1 /*
2 * Copyright (c) 2012, 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 "classfile/bytecodeAssembler.hpp"
27 #include "classfile/defaultMethods.hpp"
28 #include "classfile/genericSignatures.hpp"
29 #include "classfile/symbolTable.hpp"
30 #include "memory/allocation.hpp"
31 #include "memory/metadataFactory.hpp"
32 #include "memory/resourceArea.hpp"
33 #include "runtime/signature.hpp"
34 #include "runtime/thread.hpp"
35 #include "oops/instanceKlass.hpp"
36 #include "oops/klass.hpp"
37 #include "oops/method.hpp"
38 #include "utilities/accessFlags.hpp"
39 #include "utilities/exceptions.hpp"
40 #include "utilities/ostream.hpp"
41 #include "utilities/pair.hpp"
42 #include "utilities/resourceHash.hpp"
43
44 typedef enum { QUALIFIED, DISQUALIFIED } QualifiedState;
45
46 // Because we use an iterative algorithm when iterating over the type
47 // hierarchy, we can't use traditional scoped objects which automatically do
48 // cleanup in the destructor when the scope is exited. PseudoScope (and
49 // PseudoScopeMark) provides a similar functionality, but for when you want a
50 // scoped object in non-stack memory (such as in resource memory, as we do
51 // here). You've just got to remember to call 'destroy()' on the scope when
52 // leaving it (and marks have to be explicitly added).
53 class PseudoScopeMark : public ResourceObj {
54 public:
55 virtual void destroy() = 0;
56 };
57
58 class PseudoScope : public ResourceObj {
59 private:
60 GrowableArray<PseudoScopeMark*> _marks;
61 public:
62
63 static PseudoScope* cast(void* data) {
64 return static_cast<PseudoScope*>(data);
65 }
66
67 void add_mark(PseudoScopeMark* psm) {
68 _marks.append(psm);
69 }
70
71 void destroy() {
72 for (int i = 0; i < _marks.length(); ++i) {
73 _marks.at(i)->destroy();
74 }
75 }
76 };
77
78 class ContextMark : public PseudoScopeMark {
79 private:
80 generic::Context::Mark _mark;
81 public:
82 ContextMark(const generic::Context::Mark& cm) : _mark(cm) {}
83 virtual void destroy() { _mark.destroy(); }
84 };
85
86 #ifndef PRODUCT
87 static void print_slot(outputStream* str, Symbol* name, Symbol* signature) {
88 ResourceMark rm;
89 str->print("%s%s", name->as_C_string(), signature->as_C_string());
90 }
91
92 static void print_method(outputStream* str, Method* mo, bool with_class=true) {
93 ResourceMark rm;
94 if (with_class) {
95 str->print("%s.", mo->klass_name()->as_C_string());
96 }
97 print_slot(str, mo->name(), mo->signature());
98 }
99 #endif // ndef PRODUCT
100
101 /**
102 * Perform a depth-first iteration over the class hierarchy, applying
103 * algorithmic logic as it goes.
104 *
105 * This class is one half of the inheritance hierarchy analysis mechanism.
106 * It is meant to be used in conjunction with another class, the algorithm,
107 * which is indicated by the ALGO template parameter. This class can be
108 * paired with any algorithm class that provides the required methods.
109 *
110 * This class contains all the mechanics for iterating over the class hierarchy
111 * starting at a particular root, without recursing (thus limiting stack growth
112 * from this point). It visits each superclass (if present) and superinterface
113 * in a depth-first manner, with callbacks to the ALGO class as each class is
114 * encountered (visit()), The algorithm can cut-off further exploration of a
115 * particular branch by returning 'false' from a visit() call.
116 *
117 * The ALGO class, must provide a visit() method, which each of which will be
118 * called once for each node in the inheritance tree during the iteration. In
119 * addition, it can provide a memory block via new_node_data(InstanceKlass*),
120 * which it can use for node-specific storage (and access via the
121 * current_data() and data_at_depth(int) methods).
122 *
123 * Bare minimum needed to be an ALGO class:
124 * class Algo : public HierarchyVisitor<Algo> {
125 * void* new_node_data(InstanceKlass* cls) { return NULL; }
126 * void free_node_data(void* data) { return; }
127 * bool visit() { return true; }
128 * };
129 */
130 template <class ALGO>
131 class HierarchyVisitor : StackObj {
132 private:
133
134 class Node : public ResourceObj {
135 public:
136 InstanceKlass* _class;
137 bool _super_was_visited;
138 int _interface_index;
139 void* _algorithm_data;
140
141 Node(InstanceKlass* cls, void* data, bool visit_super)
142 : _class(cls), _super_was_visited(!visit_super),
143 _interface_index(0), _algorithm_data(data) {}
144
145 int number_of_interfaces() { return _class->local_interfaces()->length(); }
146 int interface_index() { return _interface_index; }
147 void set_super_visited() { _super_was_visited = true; }
148 void increment_visited_interface() { ++_interface_index; }
149 void set_all_interfaces_visited() {
150 _interface_index = number_of_interfaces();
151 }
152 bool has_visited_super() { return _super_was_visited; }
153 bool has_visited_all_interfaces() {
154 return interface_index() >= number_of_interfaces();
155 }
156 InstanceKlass* interface_at(int index) {
157 return InstanceKlass::cast(_class->local_interfaces()->at(index));
158 }
159 InstanceKlass* next_super() { return _class->java_super(); }
160 InstanceKlass* next_interface() {
161 return interface_at(interface_index());
162 }
163 };
164
165 bool _cancelled;
166 GrowableArray<Node*> _path;
167
168 Node* current_top() const { return _path.top(); }
169 bool has_more_nodes() const { return !_path.is_empty(); }
170 void push(InstanceKlass* cls, void* data) {
171 assert(cls != NULL, "Requires a valid instance class");
172 Node* node = new Node(cls, data, has_super(cls));
173 _path.push(node);
174 }
175 void pop() { _path.pop(); }
176
177 void reset_iteration() {
178 _cancelled = false;
179 _path.clear();
180 }
181 bool is_cancelled() const { return _cancelled; }
182
183 static bool has_super(InstanceKlass* cls) {
184 return cls->super() != NULL && !cls->is_interface();
185 }
186
187 Node* node_at_depth(int i) const {
188 return (i >= _path.length()) ? NULL : _path.at(_path.length() - i - 1);
189 }
190
191 protected:
192
193 // Accessors available to the algorithm
194 int current_depth() const { return _path.length() - 1; }
195
196 InstanceKlass* class_at_depth(int i) {
197 Node* n = node_at_depth(i);
198 return n == NULL ? NULL : n->_class;
199 }
200 InstanceKlass* current_class() { return class_at_depth(0); }
201
202 void* data_at_depth(int i) {
203 Node* n = node_at_depth(i);
204 return n == NULL ? NULL : n->_algorithm_data;
205 }
206 void* current_data() { return data_at_depth(0); }
207
208 void cancel_iteration() { _cancelled = true; }
209
210 public:
211
212 void run(InstanceKlass* root) {
213 ALGO* algo = static_cast<ALGO*>(this);
214
215 reset_iteration();
216
217 void* algo_data = algo->new_node_data(root);
218 push(root, algo_data);
219 bool top_needs_visit = true;
220
221 do {
222 Node* top = current_top();
223 if (top_needs_visit) {
224 if (algo->visit() == false) {
225 // algorithm does not want to continue along this path. Arrange
226 // it so that this state is immediately popped off the stack
227 top->set_super_visited();
228 top->set_all_interfaces_visited();
229 }
230 top_needs_visit = false;
231 }
232
233 if (top->has_visited_super() && top->has_visited_all_interfaces()) {
234 algo->free_node_data(top->_algorithm_data);
235 pop();
236 } else {
237 InstanceKlass* next = NULL;
238 if (top->has_visited_super() == false) {
239 next = top->next_super();
240 top->set_super_visited();
241 } else {
242 next = top->next_interface();
243 top->increment_visited_interface();
244 }
245 assert(next != NULL, "Otherwise we shouldn't be here");
246 algo_data = algo->new_node_data(next);
247 push(next, algo_data);
248 top_needs_visit = true;
249 }
250 } while (!is_cancelled() && has_more_nodes());
251 }
252 };
253
254 #ifndef PRODUCT
255 class PrintHierarchy : public HierarchyVisitor<PrintHierarchy> {
256 public:
257
258 bool visit() {
259 InstanceKlass* cls = current_class();
260 streamIndentor si(tty, current_depth() * 2);
261 tty->indent().print_cr("%s", cls->name()->as_C_string());
262 return true;
263 }
264
265 void* new_node_data(InstanceKlass* cls) { return NULL; }
266 void free_node_data(void* data) { return; }
267 };
268 #endif // ndef PRODUCT
269
270 // Used to register InstanceKlass objects and all related metadata structures
271 // (Methods, ConstantPools) as "in-use" by the current thread so that they can't
272 // be deallocated by class redefinition while we're using them. The classes are
273 // de-registered when this goes out of scope.
274 //
275 // Once a class is registered, we need not bother with methodHandles or
276 // constantPoolHandles for it's associated metadata.
277 class KeepAliveRegistrar : public StackObj {
278 private:
279 Thread* _thread;
280 GrowableArray<ConstantPool*> _keep_alive;
281
282 public:
283 KeepAliveRegistrar(Thread* thread) : _thread(thread), _keep_alive(20) {
284 assert(thread == Thread::current(), "Must be current thread");
285 }
286
287 ~KeepAliveRegistrar() {
288 for (int i = _keep_alive.length() - 1; i >= 0; --i) {
289 ConstantPool* cp = _keep_alive.at(i);
290 int idx = _thread->metadata_handles()->find_from_end(cp);
291 assert(idx > 0, "Must be in the list");
292 _thread->metadata_handles()->remove_at(idx);
293 }
294 }
295
296 // Register a class as 'in-use' by the thread. It's fine to register a class
297 // multiple times (though perhaps inefficient)
298 void register_class(InstanceKlass* ik) {
299 ConstantPool* cp = ik->constants();
300 _keep_alive.push(cp);
301 _thread->metadata_handles()->push(cp);
302 }
303 };
304
305 class KeepAliveVisitor : public HierarchyVisitor<KeepAliveVisitor> {
306 private:
307 KeepAliveRegistrar* _registrar;
308
309 public:
310 KeepAliveVisitor(KeepAliveRegistrar* registrar) : _registrar(registrar) {}
311
312 void* new_node_data(InstanceKlass* cls) { return NULL; }
313 void free_node_data(void* data) { return; }
314
315 bool visit() {
316 _registrar->register_class(current_class());
317 return true;
318 }
319 };
320
321 // A method family contains a set of all methods that implement a single
322 // language-level method. Because of erasure, these methods may have different
323 // signatures. As members of the set are collected while walking over the
324 // hierarchy, they are tagged with a qualification state. The qualification
325 // state for an erased method is set to disqualified if there exists a path
326 // from the root of hierarchy to the method that contains an interleaving
327 // language-equivalent method defined in an interface.
328 class MethodFamily : public ResourceObj {
329 private:
330
331 generic::MethodDescriptor* _descriptor; // language-level description
332 GrowableArray<Pair<Method*,QualifiedState> > _members;
333 ResourceHashtable<Method*, int> _member_index;
334
335 Method* _selected_target; // Filled in later, if a unique target exists
336 Symbol* _exception_message; // If no unique target is found
337
338 bool contains_method(Method* method) {
339 int* lookup = _member_index.get(method);
340 return lookup != NULL;
341 }
342
343 void add_method(Method* method, QualifiedState state) {
344 Pair<Method*,QualifiedState> entry(method, state);
345 _member_index.put(method, _members.length());
346 _members.append(entry);
347 }
348
349 void disqualify_method(Method* method) {
350 int* index = _member_index.get(method);
351 assert(index != NULL && *index >= 0 && *index < _members.length(), "bad index");
352 _members.at(*index).second = DISQUALIFIED;
353 }
354
355 Symbol* generate_no_defaults_message(TRAPS) const;
356 Symbol* generate_abstract_method_message(Method* method, TRAPS) const;
357 Symbol* generate_conflicts_message(GrowableArray<Method*>* methods, TRAPS) const;
358
359 public:
360
361 MethodFamily(generic::MethodDescriptor* canonical_desc)
362 : _descriptor(canonical_desc), _selected_target(NULL),
363 _exception_message(NULL) {}
364
365 generic::MethodDescriptor* descriptor() const { return _descriptor; }
366
367 bool descriptor_matches(generic::MethodDescriptor* md, generic::Context* ctx) {
368 return descriptor()->covariant_match(md, ctx);
369 }
370
371 void set_target_if_empty(Method* m) {
372 if (_selected_target == NULL && !m->is_overpass()) {
373 _selected_target = m;
374 }
375 }
376
377 void record_qualified_method(Method* m) {
378 // If the method already exists in the set as qualified, this operation is
379 // redundant. If it already exists as disqualified, then we leave it as
380 // disqualfied. Thus we only add to the set if it's not already in the
381 // set.
382 if (!contains_method(m)) {
383 add_method(m, QUALIFIED);
384 }
385 }
386
387 void record_disqualified_method(Method* m) {
388 // If not in the set, add it as disqualified. If it's already in the set,
389 // then set the state to disqualified no matter what the previous state was.
390 if (!contains_method(m)) {
391 add_method(m, DISQUALIFIED);
392 } else {
393 disqualify_method(m);
394 }
395 }
396
397 bool has_target() const { return _selected_target != NULL; }
398 bool throws_exception() { return _exception_message != NULL; }
399
400 Method* get_selected_target() { return _selected_target; }
401 Symbol* get_exception_message() { return _exception_message; }
402
403 // Either sets the target or the exception error message
404 void determine_target(InstanceKlass* root, TRAPS) {
405 if (has_target() || throws_exception()) {
406 return;
407 }
408
409 GrowableArray<Method*> qualified_methods;
410 for (int i = 0; i < _members.length(); ++i) {
411 Pair<Method*,QualifiedState> entry = _members.at(i);
412 if (entry.second == QUALIFIED) {
413 qualified_methods.append(entry.first);
414 }
415 }
416
417 if (qualified_methods.length() == 0) {
418 _exception_message = generate_no_defaults_message(CHECK);
419 } else if (qualified_methods.length() == 1) {
420 Method* method = qualified_methods.at(0);
421 if (method->is_abstract()) {
422 _exception_message = generate_abstract_method_message(method, CHECK);
423 } else {
424 _selected_target = qualified_methods.at(0);
425 }
426 } else {
427 _exception_message = generate_conflicts_message(&qualified_methods,CHECK);
428 }
429
430 assert((has_target() ^ throws_exception()) == 1,
431 "One and only one must be true");
432 }
433
434 bool contains_signature(Symbol* query) {
435 for (int i = 0; i < _members.length(); ++i) {
436 if (query == _members.at(i).first->signature()) {
437 return true;
438 }
439 }
440 return false;
441 }
442
443 #ifndef PRODUCT
444 void print_on(outputStream* str) const {
445 print_on(str, 0);
446 }
447
448 void print_on(outputStream* str, int indent) const {
449 streamIndentor si(str, indent * 2);
450
451 generic::Context ctx(NULL); // empty, as _descriptor already canonicalized
452 TempNewSymbol family = descriptor()->reify_signature(&ctx, Thread::current());
453 str->indent().print_cr("Logical Method %s:", family->as_C_string());
454
455 streamIndentor si2(str);
456 for (int i = 0; i < _members.length(); ++i) {
457 str->indent();
458 print_method(str, _members.at(i).first);
459 if (_members.at(i).second == DISQUALIFIED) {
460 str->print(" (disqualified)");
461 }
462 str->print_cr("");
463 }
464
465 if (_selected_target != NULL) {
466 print_selected(str, 1);
467 }
468 }
469
470 void print_selected(outputStream* str, int indent) const {
471 assert(has_target(), "Should be called otherwise");
472 streamIndentor si(str, indent * 2);
473 str->indent().print("Selected method: ");
474 print_method(str, _selected_target);
475 str->print_cr("");
476 }
477
478 void print_exception(outputStream* str, int indent) {
479 assert(throws_exception(), "Should be called otherwise");
480 streamIndentor si(str, indent * 2);
481 str->indent().print_cr("%s", _exception_message->as_C_string());
482 }
483 #endif // ndef PRODUCT
484 };
485
486 Symbol* MethodFamily::generate_no_defaults_message(TRAPS) const {
487 return SymbolTable::new_symbol("No qualifying defaults found", CHECK_NULL);
488 }
489
490 Symbol* MethodFamily::generate_abstract_method_message(Method* method, TRAPS) const {
491 Symbol* klass = method->klass_name();
492 Symbol* name = method->name();
493 Symbol* sig = method->signature();
494 stringStream ss;
495 ss.print("Method ");
496 ss.write((const char*)klass->bytes(), klass->utf8_length());
497 ss.print(".");
498 ss.write((const char*)name->bytes(), name->utf8_length());
499 ss.write((const char*)sig->bytes(), sig->utf8_length());
500 ss.print(" is abstract");
501 return SymbolTable::new_symbol(ss.base(), (int)ss.size(), CHECK_NULL);
502 }
503
504 Symbol* MethodFamily::generate_conflicts_message(GrowableArray<Method*>* methods, TRAPS) const {
505 stringStream ss;
506 ss.print("Conflicting default methods:");
507 for (int i = 0; i < methods->length(); ++i) {
508 Method* method = methods->at(i);
509 Symbol* klass = method->klass_name();
510 Symbol* name = method->name();
511 ss.print(" ");
512 ss.write((const char*)klass->bytes(), klass->utf8_length());
513 ss.print(".");
514 ss.write((const char*)name->bytes(), name->utf8_length());
515 }
516 return SymbolTable::new_symbol(ss.base(), (int)ss.size(), CHECK_NULL);
517 }
518
519 class StateRestorer;
520
521 // StatefulMethodFamily is a wrapper around MethodFamily that maintains the
522 // qualification state during hierarchy visitation, and applies that state
523 // when adding members to the MethodFamily.
524 class StatefulMethodFamily : public ResourceObj {
525 friend class StateRestorer;
526 private:
527 MethodFamily* _method;
528 QualifiedState _qualification_state;
529
530 void set_qualification_state(QualifiedState state) {
531 _qualification_state = state;
532 }
533
534 public:
535 StatefulMethodFamily(generic::MethodDescriptor* md, generic::Context* ctx) {
536 _method = new MethodFamily(md->canonicalize(ctx));
537 _qualification_state = QUALIFIED;
538 }
539
540 void set_target_if_empty(Method* m) { _method->set_target_if_empty(m); }
541
542 MethodFamily* get_method_family() { return _method; }
543
544 bool descriptor_matches(generic::MethodDescriptor* md, generic::Context* ctx) {
545 return _method->descriptor_matches(md, ctx);
546 }
547
548 StateRestorer* record_method_and_dq_further(Method* mo);
549 };
550
551 class StateRestorer : public PseudoScopeMark {
552 private:
553 StatefulMethodFamily* _method;
554 QualifiedState _state_to_restore;
555 public:
556 StateRestorer(StatefulMethodFamily* dm, QualifiedState state)
557 : _method(dm), _state_to_restore(state) {}
558 ~StateRestorer() { destroy(); }
559 void restore_state() { _method->set_qualification_state(_state_to_restore); }
560 virtual void destroy() { restore_state(); }
561 };
562
563 StateRestorer* StatefulMethodFamily::record_method_and_dq_further(Method* mo) {
564 StateRestorer* mark = new StateRestorer(this, _qualification_state);
565 if (_qualification_state == QUALIFIED) {
566 _method->record_qualified_method(mo);
567 } else {
568 _method->record_disqualified_method(mo);
569 }
570 // Everything found "above"??? this method in the hierarchy walk is set to
571 // disqualified
572 set_qualification_state(DISQUALIFIED);
573 return mark;
574 }
575
576 class StatefulMethodFamilies : public ResourceObj {
577 private:
578 GrowableArray<StatefulMethodFamily*> _methods;
579
580 public:
581 StatefulMethodFamily* find_matching(
582 generic::MethodDescriptor* md, generic::Context* ctx) {
583 for (int i = 0; i < _methods.length(); ++i) {
584 StatefulMethodFamily* existing = _methods.at(i);
585 if (existing->descriptor_matches(md, ctx)) {
586 return existing;
587 }
588 }
589 return NULL;
590 }
591
592 StatefulMethodFamily* find_matching_or_create(
593 generic::MethodDescriptor* md, generic::Context* ctx) {
594 StatefulMethodFamily* method = find_matching(md, ctx);
595 if (method == NULL) {
596 method = new StatefulMethodFamily(md, ctx);
597 _methods.append(method);
598 }
599 return method;
600 }
601
602 void extract_families_into(GrowableArray<MethodFamily*>* array) {
603 for (int i = 0; i < _methods.length(); ++i) {
604 array->append(_methods.at(i)->get_method_family());
605 }
606 }
607 };
608
609 // Represents a location corresponding to a vtable slot for methods that
610 // neither the class nor any of it's ancestors provide an implementaion.
611 // Default methods may be present to fill this slot.
612 class EmptyVtableSlot : public ResourceObj {
613 private:
614 Symbol* _name;
615 Symbol* _signature;
616 int _size_of_parameters;
617 MethodFamily* _binding;
618
619 public:
620 EmptyVtableSlot(Method* method)
621 : _name(method->name()), _signature(method->signature()),
622 _size_of_parameters(method->size_of_parameters()), _binding(NULL) {}
623
624 Symbol* name() const { return _name; }
625 Symbol* signature() const { return _signature; }
626 int size_of_parameters() const { return _size_of_parameters; }
627
628 void bind_family(MethodFamily* lm) { _binding = lm; }
629 bool is_bound() { return _binding != NULL; }
630 MethodFamily* get_binding() { return _binding; }
631
632 #ifndef PRODUCT
633 void print_on(outputStream* str) const {
634 print_slot(str, name(), signature());
635 }
636 #endif // ndef PRODUCT
637 };
638
639 static GrowableArray<EmptyVtableSlot*>* find_empty_vtable_slots(
640 InstanceKlass* klass, GrowableArray<Method*>* mirandas, TRAPS) {
641
642 assert(klass != NULL, "Must be valid class");
643
644 GrowableArray<EmptyVtableSlot*>* slots = new GrowableArray<EmptyVtableSlot*>();
645
646 // All miranda methods are obvious candidates
647 for (int i = 0; i < mirandas->length(); ++i) {
648 EmptyVtableSlot* slot = new EmptyVtableSlot(mirandas->at(i));
649 slots->append(slot);
650 }
651
652 // Also any overpasses in our superclasses, that we haven't implemented.
653 // (can't use the vtable because it is not guaranteed to be initialized yet)
654 InstanceKlass* super = klass->java_super();
655 while (super != NULL) {
656 for (int i = 0; i < super->methods()->length(); ++i) {
657 Method* m = super->methods()->at(i);
658 if (m->is_overpass()) {
659 // m is a method that would have been a miranda if not for the
660 // default method processing that occurred on behalf of our superclass,
661 // so it's a method we want to re-examine in this new context. That is,
662 // unless we have a real implementation of it in the current class.
663 Method* impl = klass->lookup_method(m->name(), m->signature());
664 if (impl == NULL || impl->is_overpass()) {
665 slots->append(new EmptyVtableSlot(m));
666 }
667 }
668 }
669 super = super->java_super();
670 }
671
672 #ifndef PRODUCT
673 if (TraceDefaultMethods) {
674 tty->print_cr("Slots that need filling:");
675 streamIndentor si(tty);
676 for (int i = 0; i < slots->length(); ++i) {
677 tty->indent();
678 slots->at(i)->print_on(tty);
679 tty->print_cr("");
680 }
681 }
682 #endif // ndef PRODUCT
683 return slots;
684 }
685
686 // Iterates over the type hierarchy looking for all methods with a specific
687 // method name. The result of this is a set of method families each of
688 // which is populated with a set of methods that implement the same
689 // language-level signature.
690 class FindMethodsByName : public HierarchyVisitor<FindMethodsByName> {
691 private:
692 // Context data
693 Thread* THREAD;
694 generic::DescriptorCache* _cache;
695 Symbol* _method_name;
696 generic::Context* _ctx;
697 StatefulMethodFamilies _families;
698
699 public:
700
701 FindMethodsByName(generic::DescriptorCache* cache, Symbol* name,
702 generic::Context* ctx, Thread* thread) :
703 _cache(cache), _method_name(name), _ctx(ctx), THREAD(thread) {}
704
705 void get_discovered_families(GrowableArray<MethodFamily*>* methods) {
706 _families.extract_families_into(methods);
707 }
708
709 void* new_node_data(InstanceKlass* cls) { return new PseudoScope(); }
710 void free_node_data(void* node_data) {
711 PseudoScope::cast(node_data)->destroy();
712 }
713
714 bool visit() {
715 PseudoScope* scope = PseudoScope::cast(current_data());
716 InstanceKlass* klass = current_class();
717 InstanceKlass* sub = current_depth() > 0 ? class_at_depth(1) : NULL;
718
719 ContextMark* cm = new ContextMark(_ctx->mark());
720 scope->add_mark(cm); // will restore context when scope is freed
721
722 _ctx->apply_type_arguments(sub, klass, THREAD);
723
724 int start, end = 0;
725 start = klass->find_method_by_name(_method_name, &end);
726 if (start != -1) {
727 for (int i = start; i < end; ++i) {
728 Method* m = klass->methods()->at(i);
729 // This gets the method's parameter list with its generic type
730 // parameters resolved
731 generic::MethodDescriptor* md = _cache->descriptor_for(m, THREAD);
732
733 // Find all methods on this hierarchy that match this method
734 // (name, signature). This class collects other families of this
735 // method name.
736 StatefulMethodFamily* family =
737 _families.find_matching_or_create(md, _ctx);
738
739 if (klass->is_interface()) {
740 // ???
741 StateRestorer* restorer = family->record_method_and_dq_further(m);
742 scope->add_mark(restorer);
743 } else {
744 // This is the rule that methods in classes "win" (bad word) over
745 // methods in interfaces. This works because of single inheritance
746 family->set_target_if_empty(m);
747 }
748 }
749 }
750 return true;
751 }
752 };
753
754 #ifndef PRODUCT
755 static void print_families(
756 GrowableArray<MethodFamily*>* methods, Symbol* match) {
757 streamIndentor si(tty, 4);
758 if (methods->length() == 0) {
759 tty->indent();
760 tty->print_cr("No Logical Method found");
761 }
762 for (int i = 0; i < methods->length(); ++i) {
763 tty->indent();
764 MethodFamily* lm = methods->at(i);
765 if (lm->contains_signature(match)) {
766 tty->print_cr("<Matching>");
767 } else {
768 tty->print_cr("<Non-Matching>");
769 }
770 lm->print_on(tty, 1);
771 }
772 }
773 #endif // ndef PRODUCT
774
775 static void merge_in_new_methods(InstanceKlass* klass,
776 GrowableArray<Method*>* new_methods, TRAPS);
777 static void create_overpasses(
778 GrowableArray<EmptyVtableSlot*>* slots, InstanceKlass* klass, TRAPS);
779
780 // This is the guts of the default methods implementation. This is called just
781 // after the classfile has been parsed if some ancestor has default methods.
782 //
783 // First if finds any name/signature slots that need any implementation (either
784 // because they are miranda or a superclass's implementation is an overpass
785 // itself). For each slot, iterate over the hierarchy, using generic signature
786 // information to partition any methods that match the name into method families
787 // where each family contains methods whose signatures are equivalent at the
788 // language level (i.e., their reified parameters match and return values are
789 // covariant). Check those sets to see if they contain a signature that matches
790 // the slot we're looking at (if we're lucky, there might be other empty slots
791 // that we can fill using the same analysis).
792 //
793 // For each slot filled, we generate an overpass method that either calls the
794 // unique default method candidate using invokespecial, or throws an exception
795 // (in the case of no default method candidates, or more than one valid
796 // candidate). These methods are then added to the class's method list. If
797 // the method set we're using contains methods (qualified or not) with a
798 // different runtime signature than the method we're creating, then we have to
799 // create bridges with those signatures too.
800 void DefaultMethods::generate_default_methods(
801 InstanceKlass* klass, GrowableArray<Method*>* mirandas, TRAPS) {
802
803 // This resource mark is the bound for all memory allocation that takes
804 // place during default method processing. After this goes out of scope,
805 // all (Resource) objects' memory will be reclaimed. Be careful if adding an
806 // embedded resource mark under here as that memory can't be used outside
807 // whatever scope it's in.
808 ResourceMark rm(THREAD);
809
810 generic::DescriptorCache cache;
811
812 // Keep entire hierarchy alive for the duration of the computation
813 KeepAliveRegistrar keepAlive(THREAD);
814 KeepAliveVisitor loadKeepAlive(&keepAlive);
815 loadKeepAlive.run(klass);
816
817 #ifndef PRODUCT
818 if (TraceDefaultMethods) {
819 ResourceMark rm; // be careful with these!
820 tty->print_cr("Class %s requires default method processing",
821 klass->name()->as_klass_external_name());
822 PrintHierarchy printer;
823 printer.run(klass);
824 }
825 #endif // ndef PRODUCT
826
827 GrowableArray<EmptyVtableSlot*>* empty_slots =
828 find_empty_vtable_slots(klass, mirandas, CHECK);
829
830 for (int i = 0; i < empty_slots->length(); ++i) {
831 EmptyVtableSlot* slot = empty_slots->at(i);
832 #ifndef PRODUCT
833 if (TraceDefaultMethods) {
834 streamIndentor si(tty, 2);
835 tty->indent().print("Looking for default methods for slot ");
836 slot->print_on(tty);
837 tty->print_cr("");
838 }
839 #endif // ndef PRODUCT
840 if (slot->is_bound()) {
841 #ifndef PRODUCT
842 if (TraceDefaultMethods) {
843 streamIndentor si(tty, 4);
844 tty->indent().print_cr("Already bound to logical method:");
845 slot->get_binding()->print_on(tty, 1);
846 }
847 #endif // ndef PRODUCT
848 continue; // covered by previous processing
849 }
850
851 generic::Context ctx(&cache);
852 FindMethodsByName visitor(&cache, slot->name(), &ctx, CHECK);
853 visitor.run(klass);
854
855 GrowableArray<MethodFamily*> discovered_families;
856 visitor.get_discovered_families(&discovered_families);
857
858 #ifndef PRODUCT
859 if (TraceDefaultMethods) {
860 print_families(&discovered_families, slot->signature());
861 }
862 #endif // ndef PRODUCT
863
864 // Find and populate any other slots that match the discovered families
865 for (int j = i; j < empty_slots->length(); ++j) {
866 EmptyVtableSlot* open_slot = empty_slots->at(j);
867
868 if (slot->name() == open_slot->name()) {
869 for (int k = 0; k < discovered_families.length(); ++k) {
870 MethodFamily* lm = discovered_families.at(k);
871
872 if (lm->contains_signature(open_slot->signature())) {
873 lm->determine_target(klass, CHECK);
874 open_slot->bind_family(lm);
875 }
876 }
877 }
878 }
879 }
880
881 #ifndef PRODUCT
882 if (TraceDefaultMethods) {
883 tty->print_cr("Creating overpasses...");
884 }
885 #endif // ndef PRODUCT
886
887 create_overpasses(empty_slots, klass, CHECK);
888
889 #ifndef PRODUCT
890 if (TraceDefaultMethods) {
891 tty->print_cr("Default method processing complete");
892 }
893 #endif // ndef PRODUCT
894 }
895
896
897 /**
898 * Generic analysis was used upon interface '_target' and found a unique
899 * default method candidate with generic signature '_method_desc'. This
900 * method is only viable if it would also be in the set of default method
901 * candidates if we ran a full analysis on the current class.
902 *
903 * The only reason that the method would not be in the set of candidates for
904 * the current class is if that there's another covariantly matching method
905 * which is "more specific" than the found method -- i.e., one could find a
906 * path in the interface hierarchy in which the matching method appears
907 * before we get to '_target'.
908 *
909 * In order to determine this, we examine all of the implemented
910 * interfaces. If we find path that leads to the '_target' interface, then
911 * we examine that path to see if there are any methods that would shadow
912 * the selected method along that path.
913 */
914 class ShadowChecker : public HierarchyVisitor<ShadowChecker> {
915 private:
916 generic::DescriptorCache* _cache;
917 Thread* THREAD;
918
919 InstanceKlass* _target;
920
921 Symbol* _method_name;
922 InstanceKlass* _method_holder;
923 generic::MethodDescriptor* _method_desc;
924 bool _found_shadow;
925
926 bool path_has_shadow() {
927 generic::Context ctx(_cache);
928
929 for (int i = current_depth() - 1; i > 0; --i) {
930 InstanceKlass* ik = class_at_depth(i);
931 InstanceKlass* sub = class_at_depth(i + 1);
932 ctx.apply_type_arguments(sub, ik, THREAD);
933
934 if (ik->is_interface()) {
935 int end;
936 int start = ik->find_method_by_name(_method_name, &end);
937 if (start != -1) {
938 for (int j = start; j < end; ++j) {
939 Method* mo = ik->methods()->at(j);
940 generic::MethodDescriptor* md = _cache->descriptor_for(mo, THREAD);
941 if (_method_desc->covariant_match(md, &ctx)) {
942 return true;
943 }
944 }
945 }
946 }
947 }
948 return false;
949 }
950
951 public:
952
953 ShadowChecker(generic::DescriptorCache* cache, Thread* thread,
954 Symbol* name, InstanceKlass* holder, generic::MethodDescriptor* desc,
955 InstanceKlass* target)
956 : _cache(cache), THREAD(thread), _method_name(name), _method_holder(holder),
957 _method_desc(desc), _target(target), _found_shadow(false) {}
958
959 void* new_node_data(InstanceKlass* cls) { return NULL; }
960 void free_node_data(void* data) { return; }
961
962 bool visit() {
963 InstanceKlass* ik = current_class();
964 if (ik == _target && current_depth() == 1) {
965 return false; // This was the specified super -- no need to search it
966 }
967 if (ik == _method_holder || ik == _target) {
968 // We found a path that should be examined to see if it shadows _method
969 if (path_has_shadow()) {
970 _found_shadow = true;
971 cancel_iteration();
972 }
973 return false; // no need to continue up hierarchy
974 }
975 return true;
976 }
977
978 bool found_shadow() { return _found_shadow; }
979 };
980
981 // This is called during linktime when we find an invokespecial call that
982 // refers to a direct superinterface. It indicates that we should find the
983 // default method in the hierarchy of that superinterface, and if that method
984 // would have been a candidate from the point of view of 'this' class, then we
985 // return that method.
986 Method* DefaultMethods::find_super_default(
987 Klass* cls, Klass* super, Symbol* method_name, Symbol* sig, TRAPS) {
988
989 ResourceMark rm(THREAD);
990
991 assert(cls != NULL && super != NULL, "Need real classes");
992
993 InstanceKlass* current_class = InstanceKlass::cast(cls);
994 InstanceKlass* direction = InstanceKlass::cast(super);
995
996 // Keep entire hierarchy alive for the duration of the computation
997 KeepAliveRegistrar keepAlive(THREAD);
998 KeepAliveVisitor loadKeepAlive(&keepAlive);
999 loadKeepAlive.run(current_class);
1000
1001 #ifndef PRODUCT
1002 if (TraceDefaultMethods) {
1003 tty->print_cr("Finding super default method %s.%s%s from %s",
1004 direction->name()->as_C_string(),
1005 method_name->as_C_string(), sig->as_C_string(),
1006 current_class->name()->as_C_string());
1007 }
1008 #endif // ndef PRODUCT
1009
1010 if (!direction->is_interface()) {
1011 // We should not be here
1012 return NULL;
1013 }
1014
1015 generic::DescriptorCache cache;
1016 generic::Context ctx(&cache);
1017
1018 // Prime the initial generic context for current -> direction
1019 ctx.apply_type_arguments(current_class, direction, CHECK_NULL);
1020
1021 FindMethodsByName visitor(&cache, method_name, &ctx, CHECK_NULL);
1022 visitor.run(direction);
1023
1024 GrowableArray<MethodFamily*> families;
1025 visitor.get_discovered_families(&families);
1026
1027 #ifndef PRODUCT
1028 if (TraceDefaultMethods) {
1029 print_families(&families, sig);
1030 }
1031 #endif // ndef PRODUCT
1032
1033 MethodFamily* selected_family = NULL;
1034
1035 for (int i = 0; i < families.length(); ++i) {
1036 MethodFamily* lm = families.at(i);
1037 if (lm->contains_signature(sig)) {
1038 lm->determine_target(current_class, CHECK_NULL);
1039 selected_family = lm;
1040 }
1041 }
1042
1043 if (selected_family->has_target()) {
1044 Method* target = selected_family->get_selected_target();
1045 InstanceKlass* holder = InstanceKlass::cast(target->method_holder());
1046
1047 // Verify that the identified method is valid from the context of
1048 // the current class
1049 ShadowChecker checker(&cache, THREAD, target->name(),
1050 holder, selected_family->descriptor(), direction);
1051 checker.run(current_class);
1052
1053 if (checker.found_shadow()) {
1054 #ifndef PRODUCT
1055 if (TraceDefaultMethods) {
1056 tty->print_cr(" Only candidate found was shadowed.");
1057 }
1058 #endif // ndef PRODUCT
1059 THROW_MSG_(vmSymbols::java_lang_AbstractMethodError(),
1060 "Accessible default method not found", NULL);
1061 } else {
1062 #ifndef PRODUCT
1063 if (TraceDefaultMethods) {
1064 tty->print(" Returning ");
1065 print_method(tty, target, true);
1066 tty->print_cr("");
1067 }
1068 #endif // ndef PRODUCT
1069 return target;
1070 }
1071 } else {
1072 assert(selected_family->throws_exception(), "must have target or throw");
1073 THROW_MSG_(vmSymbols::java_lang_AbstractMethodError(),
1074 selected_family->get_exception_message()->as_C_string(), NULL);
1075 }
1076 }
1077
1078
1079 static int assemble_redirect(
1080 BytecodeConstantPool* cp, BytecodeBuffer* buffer,
1081 Symbol* incoming, Method* target, TRAPS) {
1082
1083 BytecodeAssembler assem(buffer, cp);
1084
1085 SignatureStream in(incoming, true);
1086 SignatureStream out(target->signature(), true);
1087 u2 parameter_count = 0;
1088
1089 assem.aload(parameter_count++); // load 'this'
1090
1091 while (!in.at_return_type()) {
1092 assert(!out.at_return_type(), "Parameter counts do not match");
1093 BasicType bt = in.type();
1094 assert(out.type() == bt, "Parameter types are not compatible");
1095 assem.load(bt, parameter_count);
1096 if (in.is_object() && in.as_symbol(THREAD) != out.as_symbol(THREAD)) {
1097 assem.checkcast(out.as_symbol(THREAD));
1098 } else if (bt == T_LONG || bt == T_DOUBLE) {
1099 ++parameter_count; // longs and doubles use two slots
1100 }
1101 ++parameter_count;
1102 in.next();
1103 out.next();
1104 }
1105 assert(out.at_return_type(), "Parameter counts do not match");
1106 assert(in.type() == out.type(), "Return types are not compatible");
1107
1108 if (parameter_count == 1 && (in.type() == T_LONG || in.type() == T_DOUBLE)) {
1109 ++parameter_count; // need room for return value
1110 }
1111 if (target->method_holder()->is_interface()) {
1112 assem.invokespecial(target);
1113 } else {
1114 assem.invokevirtual(target);
1115 }
1116
1117 if (in.is_object() && in.as_symbol(THREAD) != out.as_symbol(THREAD)) {
1118 assem.checkcast(in.as_symbol(THREAD));
1119 }
1120 assem._return(in.type());
1121 return parameter_count;
1122 }
1123
1124 static int assemble_abstract_method_error(
1125 BytecodeConstantPool* cp, BytecodeBuffer* buffer, Symbol* message, TRAPS) {
1126
1127 Symbol* errorName = vmSymbols::java_lang_AbstractMethodError();
1128 Symbol* init = vmSymbols::object_initializer_name();
1129 Symbol* sig = vmSymbols::string_void_signature();
1130
1131 BytecodeAssembler assem(buffer, cp);
1132
1133 assem._new(errorName);
1134 assem.dup();
1135 assem.load_string(message);
1136 assem.invokespecial(errorName, init, sig);
1137 assem.athrow();
1138
1139 return 3; // max stack size: [ exception, exception, string ]
1140 }
1141
1142 static Method* new_method(
1143 BytecodeConstantPool* cp, BytecodeBuffer* bytecodes, Symbol* name,
1144 Symbol* sig, AccessFlags flags, int max_stack, int params,
1145 ConstMethod::MethodType mt, TRAPS) {
1146
1147 address code_start = static_cast<address>(bytecodes->adr_at(0));
1148 int code_length = bytecodes->length();
1149
1150 Method* m = Method::allocate(cp->pool_holder()->class_loader_data(),
1151 code_length, flags, 0, 0, 0, 0, 0, 0,
1152 mt, CHECK_NULL);
1153
1154 m->set_constants(NULL); // This will get filled in later
1155 m->set_name_index(cp->utf8(name));
1156 m->set_signature_index(cp->utf8(sig));
1157 #ifdef CC_INTERP
1158 ResultTypeFinder rtf(sig);
1159 m->set_result_index(rtf.type());
1160 #endif
1161 m->set_size_of_parameters(params);
1162 m->set_max_stack(max_stack);
1163 m->set_max_locals(params);
1164 m->constMethod()->set_stackmap_data(NULL);
1165 m->set_code(code_start);
1166 m->set_force_inline(true);
1167
1168 return m;
1169 }
1170
1171 static void switchover_constant_pool(BytecodeConstantPool* bpool,
1172 InstanceKlass* klass, GrowableArray<Method*>* new_methods, TRAPS) {
1173
1174 if (new_methods->length() > 0) {
1175 ConstantPool* cp = bpool->create_constant_pool(CHECK);
1176 if (cp != klass->constants()) {
1177 klass->class_loader_data()->add_to_deallocate_list(klass->constants());
1178 klass->set_constants(cp);
1179 cp->set_pool_holder(klass);
1180
1181 for (int i = 0; i < new_methods->length(); ++i) {
1182 new_methods->at(i)->set_constants(cp);
1183 }
1184 for (int i = 0; i < klass->methods()->length(); ++i) {
1185 Method* mo = klass->methods()->at(i);
1186 mo->set_constants(cp);
1187 }
1188 }
1189 }
1190 }
1191
1192 // A "bridge" is a method created by javac to bridge the gap between
1193 // an implementation and a generically-compatible, but different, signature.
1194 // Bridges have actual bytecode implementation in classfiles.
1195 // An "overpass", on the other hand, performs the same function as a bridge
1196 // but does not occur in a classfile; the VM creates overpass itself,
1197 // when it needs a path to get from a call site to an default method, and
1198 // a bridge doesn't exist.
1199 static void create_overpasses(
1200 GrowableArray<EmptyVtableSlot*>* slots,
1201 InstanceKlass* klass, TRAPS) {
1202
1203 GrowableArray<Method*> overpasses;
1204 BytecodeConstantPool bpool(klass->constants());
1205
1206 for (int i = 0; i < slots->length(); ++i) {
1207 EmptyVtableSlot* slot = slots->at(i);
1208
1209 if (slot->is_bound()) {
1210 MethodFamily* method = slot->get_binding();
1211 int max_stack = 0;
1212 BytecodeBuffer buffer;
1213
1214 #ifndef PRODUCT
1215 if (TraceDefaultMethods) {
1216 tty->print("for slot: ");
1217 slot->print_on(tty);
1218 tty->print_cr("");
1219 if (method->has_target()) {
1220 method->print_selected(tty, 1);
1221 } else {
1222 method->print_exception(tty, 1);
1223 }
1224 }
1225 #endif // ndef PRODUCT
1226 if (method->has_target()) {
1227 Method* selected = method->get_selected_target();
1228 max_stack = assemble_redirect(
1229 &bpool, &buffer, slot->signature(), selected, CHECK);
1230 } else if (method->throws_exception()) {
1231 max_stack = assemble_abstract_method_error(
1232 &bpool, &buffer, method->get_exception_message(), CHECK);
1233 }
1234 AccessFlags flags = accessFlags_from(
1235 JVM_ACC_PUBLIC | JVM_ACC_SYNTHETIC | JVM_ACC_BRIDGE);
1236 Method* m = new_method(&bpool, &buffer, slot->name(), slot->signature(),
1237 flags, max_stack, slot->size_of_parameters(),
1238 ConstMethod::OVERPASS, CHECK);
1239 if (m != NULL) {
1240 overpasses.push(m);
1241 }
1242 }
1243 }
1244
1245 #ifndef PRODUCT
1246 if (TraceDefaultMethods) {
1247 tty->print_cr("Created %d overpass methods", overpasses.length());
1248 }
1249 #endif // ndef PRODUCT
1250
1251 switchover_constant_pool(&bpool, klass, &overpasses, CHECK);
1252 merge_in_new_methods(klass, &overpasses, CHECK);
1253 }
1254
1255 static void sort_methods(GrowableArray<Method*>* methods) {
1256 // Note that this must sort using the same key as is used for sorting
1257 // methods in InstanceKlass.
1258 bool sorted = true;
1259 for (int i = methods->length() - 1; i > 0; --i) {
1260 for (int j = 0; j < i; ++j) {
1261 Method* m1 = methods->at(j);
1262 Method* m2 = methods->at(j + 1);
1263 if ((uintptr_t)m1->name() > (uintptr_t)m2->name()) {
1264 methods->at_put(j, m2);
1265 methods->at_put(j + 1, m1);
1266 sorted = false;
1267 }
1268 }
1269 if (sorted) break;
1270 sorted = true;
1271 }
1272 #ifdef ASSERT
1273 uintptr_t prev = 0;
1274 for (int i = 0; i < methods->length(); ++i) {
1275 Method* mh = methods->at(i);
1276 uintptr_t nv = (uintptr_t)mh->name();
1277 assert(nv >= prev, "Incorrect overpass method ordering");
1278 prev = nv;
1279 }
1280 #endif
1281 }
1282
1283 static void merge_in_new_methods(InstanceKlass* klass,
1284 GrowableArray<Method*>* new_methods, TRAPS) {
1285
1286 enum { ANNOTATIONS, PARAMETERS, DEFAULTS, NUM_ARRAYS };
1287
1288 Array<AnnotationArray*>* original_annots[NUM_ARRAYS] = { NULL };
1289
1290 Array<Method*>* original_methods = klass->methods();
1291 Annotations* annots = klass->annotations();
1292 if (annots != NULL) {
1293 original_annots[ANNOTATIONS] = annots->methods_annotations();
1294 original_annots[PARAMETERS] = annots->methods_parameter_annotations();
1295 original_annots[DEFAULTS] = annots->methods_default_annotations();
1296 }
1297
1298 Array<int>* original_ordering = klass->method_ordering();
1299 Array<int>* merged_ordering = Universe::the_empty_int_array();
1300
1301 int new_size = klass->methods()->length() + new_methods->length();
1302
1303 Array<AnnotationArray*>* merged_annots[NUM_ARRAYS];
1304
1305 Array<Method*>* merged_methods = MetadataFactory::new_array<Method*>(
1306 klass->class_loader_data(), new_size, NULL, CHECK);
1307 for (int i = 0; i < NUM_ARRAYS; ++i) {
1308 if (original_annots[i] != NULL) {
1309 merged_annots[i] = MetadataFactory::new_array<AnnotationArray*>(
1310 klass->class_loader_data(), new_size, CHECK);
1311 } else {
1312 merged_annots[i] = NULL;
1313 }
1314 }
1315 if (original_ordering != NULL && original_ordering->length() > 0) {
1316 merged_ordering = MetadataFactory::new_array<int>(
1317 klass->class_loader_data(), new_size, CHECK);
1318 }
1319 int method_order_index = klass->methods()->length();
1320
1321 sort_methods(new_methods);
1322
1323 // Perform grand merge of existing methods and new methods
1324 int orig_idx = 0;
1325 int new_idx = 0;
1326
1327 for (int i = 0; i < new_size; ++i) {
1328 Method* orig_method = NULL;
1329 Method* new_method = NULL;
1330 if (orig_idx < original_methods->length()) {
1331 orig_method = original_methods->at(orig_idx);
1332 }
1333 if (new_idx < new_methods->length()) {
1334 new_method = new_methods->at(new_idx);
1335 }
1336
1337 if (orig_method != NULL &&
1338 (new_method == NULL || orig_method->name() < new_method->name())) {
1339 merged_methods->at_put(i, orig_method);
1340 original_methods->at_put(orig_idx, NULL);
1341 for (int j = 0; j < NUM_ARRAYS; ++j) {
1342 if (merged_annots[j] != NULL) {
1343 merged_annots[j]->at_put(i, original_annots[j]->at(orig_idx));
1344 original_annots[j]->at_put(orig_idx, NULL);
1345 }
1346 }
1347 if (merged_ordering->length() > 0) {
1348 merged_ordering->at_put(i, original_ordering->at(orig_idx));
1349 }
1350 ++orig_idx;
1351 } else {
1352 merged_methods->at_put(i, new_method);
1353 if (merged_ordering->length() > 0) {
1354 merged_ordering->at_put(i, method_order_index++);
1355 }
1356 ++new_idx;
1357 }
1358 // update idnum for new location
1359 merged_methods->at(i)->set_method_idnum(i);
1360 }
1361
1362 // Verify correct order
1363 #ifdef ASSERT
1364 uintptr_t prev = 0;
1365 for (int i = 0; i < merged_methods->length(); ++i) {
1366 Method* mo = merged_methods->at(i);
1367 uintptr_t nv = (uintptr_t)mo->name();
1368 assert(nv >= prev, "Incorrect method ordering");
1369 prev = nv;
1370 }
1371 #endif
1372
1373 // Replace klass methods with new merged lists
1374 klass->set_methods(merged_methods);
1375 if (annots != NULL) {
1376 annots->set_methods_annotations(merged_annots[ANNOTATIONS]);
1377 annots->set_methods_parameter_annotations(merged_annots[PARAMETERS]);
1378 annots->set_methods_default_annotations(merged_annots[DEFAULTS]);
1379 } else {
1380 assert(merged_annots[ANNOTATIONS] == NULL, "Must be");
1381 assert(merged_annots[PARAMETERS] == NULL, "Must be");
1382 assert(merged_annots[DEFAULTS] == NULL, "Must be");
1383 }
1384
1385 ClassLoaderData* cld = klass->class_loader_data();
1386 MetadataFactory::free_array(cld, original_methods);
1387 for (int i = 0; i < NUM_ARRAYS; ++i) {
1388 MetadataFactory::free_array(cld, original_annots[i]);
1389 }
1390 if (original_ordering->length() > 0) {
1391 klass->set_method_ordering(merged_ordering);
1392 MetadataFactory::free_array(cld, original_ordering);
1393 }
1394 }
1395