Fri, 30 Aug 2013 09:50:49 +0100
Merge
1 /*
2 * Copyright (c) 2012, 2013, 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 */
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"
44 typedef enum { QUALIFIED, DISQUALIFIED } QualifiedState;
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 };
58 class PseudoScope : public ResourceObj {
59 private:
60 GrowableArray<PseudoScopeMark*> _marks;
61 public:
63 static PseudoScope* cast(void* data) {
64 return static_cast<PseudoScope*>(data);
65 }
67 void add_mark(PseudoScopeMark* psm) {
68 _marks.append(psm);
69 }
71 void destroy() {
72 for (int i = 0; i < _marks.length(); ++i) {
73 _marks.at(i)->destroy();
74 }
75 }
76 };
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 };
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 }
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
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:
134 class Node : public ResourceObj {
135 public:
136 InstanceKlass* _class;
137 bool _super_was_visited;
138 int _interface_index;
139 void* _algorithm_data;
141 Node(InstanceKlass* cls, void* data, bool visit_super)
142 : _class(cls), _super_was_visited(!visit_super),
143 _interface_index(0), _algorithm_data(data) {}
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 };
165 bool _cancelled;
166 GrowableArray<Node*> _path;
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(); }
177 void reset_iteration() {
178 _cancelled = false;
179 _path.clear();
180 }
181 bool is_cancelled() const { return _cancelled; }
183 static bool has_super(InstanceKlass* cls) {
184 return cls->super() != NULL && !cls->is_interface();
185 }
187 Node* node_at_depth(int i) const {
188 return (i >= _path.length()) ? NULL : _path.at(_path.length() - i - 1);
189 }
191 protected:
193 // Accessors available to the algorithm
194 int current_depth() const { return _path.length() - 1; }
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); }
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); }
208 void cancel_iteration() { _cancelled = true; }
210 public:
212 void run(InstanceKlass* root) {
213 ALGO* algo = static_cast<ALGO*>(this);
215 reset_iteration();
217 void* algo_data = algo->new_node_data(root);
218 push(root, algo_data);
219 bool top_needs_visit = true;
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 }
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 };
254 #ifndef PRODUCT
255 class PrintHierarchy : public HierarchyVisitor<PrintHierarchy> {
256 public:
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 }
265 void* new_node_data(InstanceKlass* cls) { return NULL; }
266 void free_node_data(void* data) { return; }
267 };
268 #endif // ndef PRODUCT
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;
282 public:
283 KeepAliveRegistrar(Thread* thread) : _thread(thread), _keep_alive(20) {
284 assert(thread == Thread::current(), "Must be current thread");
285 }
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 }
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 };
305 class KeepAliveVisitor : public HierarchyVisitor<KeepAliveVisitor> {
306 private:
307 KeepAliveRegistrar* _registrar;
309 public:
310 KeepAliveVisitor(KeepAliveRegistrar* registrar) : _registrar(registrar) {}
312 void* new_node_data(InstanceKlass* cls) { return NULL; }
313 void free_node_data(void* data) { return; }
315 bool visit() {
316 _registrar->register_class(current_class());
317 return true;
318 }
319 };
322 // A method family contains a set of all methods that implement a single
323 // erased method. 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 // erased method defined in an interface.
329 class MethodFamily : public ResourceObj {
330 private:
332 GrowableArray<Pair<Method*,QualifiedState> > _members;
333 ResourceHashtable<Method*, int> _member_index;
335 Method* _selected_target; // Filled in later, if a unique target exists
336 Symbol* _exception_message; // If no unique target is found
338 bool contains_method(Method* method) {
339 int* lookup = _member_index.get(method);
340 return lookup != NULL;
341 }
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 }
349 void disqualify_method(Method* method) {
350 int* index = _member_index.get(method);
351 guarantee(index != NULL && *index >= 0 && *index < _members.length(), "bad index");
352 _members.at(*index).second = DISQUALIFIED;
353 }
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;
359 public:
361 MethodFamily()
362 : _selected_target(NULL), _exception_message(NULL) {}
364 void set_target_if_empty(Method* m) {
365 if (_selected_target == NULL && !m->is_overpass()) {
366 _selected_target = m;
367 }
368 }
370 void record_qualified_method(Method* m) {
371 // If the method already exists in the set as qualified, this operation is
372 // redundant. If it already exists as disqualified, then we leave it as
373 // disqualfied. Thus we only add to the set if it's not already in the
374 // set.
375 if (!contains_method(m)) {
376 add_method(m, QUALIFIED);
377 }
378 }
380 void record_disqualified_method(Method* m) {
381 // If not in the set, add it as disqualified. If it's already in the set,
382 // then set the state to disqualified no matter what the previous state was.
383 if (!contains_method(m)) {
384 add_method(m, DISQUALIFIED);
385 } else {
386 disqualify_method(m);
387 }
388 }
390 bool has_target() const { return _selected_target != NULL; }
391 bool throws_exception() { return _exception_message != NULL; }
393 Method* get_selected_target() { return _selected_target; }
394 Symbol* get_exception_message() { return _exception_message; }
396 // Either sets the target or the exception error message
397 void determine_target(InstanceKlass* root, TRAPS) {
398 if (has_target() || throws_exception()) {
399 return;
400 }
402 GrowableArray<Method*> qualified_methods;
403 for (int i = 0; i < _members.length(); ++i) {
404 Pair<Method*,QualifiedState> entry = _members.at(i);
405 if (entry.second == QUALIFIED) {
406 qualified_methods.append(entry.first);
407 }
408 }
410 if (qualified_methods.length() == 0) {
411 _exception_message = generate_no_defaults_message(CHECK);
412 } else if (qualified_methods.length() == 1) {
413 Method* method = qualified_methods.at(0);
414 if (method->is_abstract()) {
415 _exception_message = generate_abstract_method_message(method, CHECK);
416 } else {
417 _selected_target = qualified_methods.at(0);
418 }
419 } else {
420 _exception_message = generate_conflicts_message(&qualified_methods,CHECK);
421 }
423 assert((has_target() ^ throws_exception()) == 1,
424 "One and only one must be true");
425 }
427 bool contains_signature(Symbol* query) {
428 for (int i = 0; i < _members.length(); ++i) {
429 if (query == _members.at(i).first->signature()) {
430 return true;
431 }
432 }
433 return false;
434 }
436 #ifndef PRODUCT
437 void print_sig_on(outputStream* str, Symbol* signature, int indent) const {
438 streamIndentor si(str, indent * 2);
440 str->indent().print_cr("Logical Method %s:", signature->as_C_string());
442 streamIndentor si2(str);
443 for (int i = 0; i < _members.length(); ++i) {
444 str->indent();
445 print_method(str, _members.at(i).first);
446 if (_members.at(i).second == DISQUALIFIED) {
447 str->print(" (disqualified)");
448 }
449 str->print_cr("");
450 }
452 if (_selected_target != NULL) {
453 print_selected(str, 1);
454 }
455 }
457 void print_selected(outputStream* str, int indent) const {
458 assert(has_target(), "Should be called otherwise");
459 streamIndentor si(str, indent * 2);
460 str->indent().print("Selected method: ");
461 print_method(str, _selected_target);
462 str->print_cr("");
463 }
465 void print_exception(outputStream* str, int indent) {
466 assert(throws_exception(), "Should be called otherwise");
467 streamIndentor si(str, indent * 2);
468 str->indent().print_cr("%s", _exception_message->as_C_string());
469 }
470 #endif // ndef PRODUCT
471 };
473 Symbol* MethodFamily::generate_no_defaults_message(TRAPS) const {
474 return SymbolTable::new_symbol("No qualifying defaults found", CHECK_NULL);
475 }
477 Symbol* MethodFamily::generate_abstract_method_message(Method* method, TRAPS) const {
478 Symbol* klass = method->klass_name();
479 Symbol* name = method->name();
480 Symbol* sig = method->signature();
481 stringStream ss;
482 ss.print("Method ");
483 ss.write((const char*)klass->bytes(), klass->utf8_length());
484 ss.print(".");
485 ss.write((const char*)name->bytes(), name->utf8_length());
486 ss.write((const char*)sig->bytes(), sig->utf8_length());
487 ss.print(" is abstract");
488 return SymbolTable::new_symbol(ss.base(), (int)ss.size(), CHECK_NULL);
489 }
491 Symbol* MethodFamily::generate_conflicts_message(GrowableArray<Method*>* methods, TRAPS) const {
492 stringStream ss;
493 ss.print("Conflicting default methods:");
494 for (int i = 0; i < methods->length(); ++i) {
495 Method* method = methods->at(i);
496 Symbol* klass = method->klass_name();
497 Symbol* name = method->name();
498 ss.print(" ");
499 ss.write((const char*)klass->bytes(), klass->utf8_length());
500 ss.print(".");
501 ss.write((const char*)name->bytes(), name->utf8_length());
502 }
503 return SymbolTable::new_symbol(ss.base(), (int)ss.size(), CHECK_NULL);
504 }
506 // A generic method family contains a set of all methods that implement a single
507 // language-level method. Because of erasure, these methods may have different
508 // signatures. As members of the set are collected while walking over the
509 // hierarchy, they are tagged with a qualification state. The qualification
510 // state for an erased method is set to disqualified if there exists a path
511 // from the root of hierarchy to the method that contains an interleaving
512 // language-equivalent method defined in an interface.
513 class GenericMethodFamily : public MethodFamily {
514 private:
516 generic::MethodDescriptor* _descriptor; // language-level description
518 public:
520 GenericMethodFamily(generic::MethodDescriptor* canonical_desc)
521 : _descriptor(canonical_desc) {}
523 generic::MethodDescriptor* descriptor() const { return _descriptor; }
525 bool descriptor_matches(generic::MethodDescriptor* md, generic::Context* ctx) {
526 return descriptor()->covariant_match(md, ctx);
527 }
529 #ifndef PRODUCT
530 Symbol* get_generic_sig() const {
532 generic::Context ctx(NULL); // empty, as _descriptor already canonicalized
533 TempNewSymbol sig = descriptor()->reify_signature(&ctx, Thread::current());
534 return sig;
535 }
536 #endif // ndef PRODUCT
537 };
539 class StateRestorer;
541 // StatefulMethodFamily is a wrapper around a MethodFamily that maintains the
542 // qualification state during hierarchy visitation, and applies that state
543 // when adding members to the MethodFamily
544 class StatefulMethodFamily : public ResourceObj {
545 friend class StateRestorer;
546 private:
547 QualifiedState _qualification_state;
549 void set_qualification_state(QualifiedState state) {
550 _qualification_state = state;
551 }
553 protected:
554 MethodFamily* _method_family;
556 public:
557 StatefulMethodFamily() {
558 _method_family = new MethodFamily();
559 _qualification_state = QUALIFIED;
560 }
562 StatefulMethodFamily(MethodFamily* mf) {
563 _method_family = mf;
564 _qualification_state = QUALIFIED;
565 }
567 void set_target_if_empty(Method* m) { _method_family->set_target_if_empty(m); }
569 MethodFamily* get_method_family() { return _method_family; }
571 StateRestorer* record_method_and_dq_further(Method* mo);
572 };
575 // StatefulGenericMethodFamily is a wrapper around GenericMethodFamily that maintains the
576 // qualification state during hierarchy visitation, and applies that state
577 // when adding members to the GenericMethodFamily.
578 class StatefulGenericMethodFamily : public StatefulMethodFamily {
580 public:
581 StatefulGenericMethodFamily(generic::MethodDescriptor* md, generic::Context* ctx)
582 : StatefulMethodFamily(new GenericMethodFamily(md->canonicalize(ctx))) {
584 }
585 GenericMethodFamily* get_method_family() {
586 return (GenericMethodFamily*)_method_family;
587 }
589 bool descriptor_matches(generic::MethodDescriptor* md, generic::Context* ctx) {
590 return get_method_family()->descriptor_matches(md, ctx);
591 }
592 };
594 class StateRestorer : public PseudoScopeMark {
595 private:
596 StatefulMethodFamily* _method;
597 QualifiedState _state_to_restore;
598 public:
599 StateRestorer(StatefulMethodFamily* dm, QualifiedState state)
600 : _method(dm), _state_to_restore(state) {}
601 ~StateRestorer() { destroy(); }
602 void restore_state() { _method->set_qualification_state(_state_to_restore); }
603 virtual void destroy() { restore_state(); }
604 };
606 StateRestorer* StatefulMethodFamily::record_method_and_dq_further(Method* mo) {
607 StateRestorer* mark = new StateRestorer(this, _qualification_state);
608 if (_qualification_state == QUALIFIED) {
609 _method_family->record_qualified_method(mo);
610 } else {
611 _method_family->record_disqualified_method(mo);
612 }
613 // Everything found "above"??? this method in the hierarchy walk is set to
614 // disqualified
615 set_qualification_state(DISQUALIFIED);
616 return mark;
617 }
619 class StatefulGenericMethodFamilies : public ResourceObj {
620 private:
621 GrowableArray<StatefulGenericMethodFamily*> _methods;
623 public:
624 StatefulGenericMethodFamily* find_matching(
625 generic::MethodDescriptor* md, generic::Context* ctx) {
626 for (int i = 0; i < _methods.length(); ++i) {
627 StatefulGenericMethodFamily* existing = _methods.at(i);
628 if (existing->descriptor_matches(md, ctx)) {
629 return existing;
630 }
631 }
632 return NULL;
633 }
635 StatefulGenericMethodFamily* find_matching_or_create(
636 generic::MethodDescriptor* md, generic::Context* ctx) {
637 StatefulGenericMethodFamily* method = find_matching(md, ctx);
638 if (method == NULL) {
639 method = new StatefulGenericMethodFamily(md, ctx);
640 _methods.append(method);
641 }
642 return method;
643 }
645 void extract_families_into(GrowableArray<GenericMethodFamily*>* array) {
646 for (int i = 0; i < _methods.length(); ++i) {
647 array->append(_methods.at(i)->get_method_family());
648 }
649 }
650 };
652 // Represents a location corresponding to a vtable slot for methods that
653 // neither the class nor any of it's ancestors provide an implementaion.
654 // Default methods may be present to fill this slot.
655 class EmptyVtableSlot : public ResourceObj {
656 private:
657 Symbol* _name;
658 Symbol* _signature;
659 int _size_of_parameters;
660 MethodFamily* _binding;
662 public:
663 EmptyVtableSlot(Method* method)
664 : _name(method->name()), _signature(method->signature()),
665 _size_of_parameters(method->size_of_parameters()), _binding(NULL) {}
667 Symbol* name() const { return _name; }
668 Symbol* signature() const { return _signature; }
669 int size_of_parameters() const { return _size_of_parameters; }
671 void bind_family(MethodFamily* lm) { _binding = lm; }
672 bool is_bound() { return _binding != NULL; }
673 MethodFamily* get_binding() { return _binding; }
675 #ifndef PRODUCT
676 void print_on(outputStream* str) const {
677 print_slot(str, name(), signature());
678 }
679 #endif // ndef PRODUCT
680 };
682 static GrowableArray<EmptyVtableSlot*>* find_empty_vtable_slots(
683 InstanceKlass* klass, GrowableArray<Method*>* mirandas, TRAPS) {
685 assert(klass != NULL, "Must be valid class");
687 GrowableArray<EmptyVtableSlot*>* slots = new GrowableArray<EmptyVtableSlot*>();
689 // All miranda methods are obvious candidates
690 for (int i = 0; i < mirandas->length(); ++i) {
691 EmptyVtableSlot* slot = new EmptyVtableSlot(mirandas->at(i));
692 slots->append(slot);
693 }
695 // Also any overpasses in our superclasses, that we haven't implemented.
696 // (can't use the vtable because it is not guaranteed to be initialized yet)
697 InstanceKlass* super = klass->java_super();
698 while (super != NULL) {
699 for (int i = 0; i < super->methods()->length(); ++i) {
700 Method* m = super->methods()->at(i);
701 if (m->is_overpass()) {
702 // m is a method that would have been a miranda if not for the
703 // default method processing that occurred on behalf of our superclass,
704 // so it's a method we want to re-examine in this new context. That is,
705 // unless we have a real implementation of it in the current class.
706 Method* impl = klass->lookup_method(m->name(), m->signature());
707 if (impl == NULL || impl->is_overpass()) {
708 slots->append(new EmptyVtableSlot(m));
709 }
710 }
711 }
712 super = super->java_super();
713 }
715 #ifndef PRODUCT
716 if (TraceDefaultMethods) {
717 tty->print_cr("Slots that need filling:");
718 streamIndentor si(tty);
719 for (int i = 0; i < slots->length(); ++i) {
720 tty->indent();
721 slots->at(i)->print_on(tty);
722 tty->print_cr("");
723 }
724 }
725 #endif // ndef PRODUCT
726 return slots;
727 }
729 // Iterates over the superinterface type hierarchy looking for all methods
730 // with a specific erased signature.
731 class FindMethodsByErasedSig : public HierarchyVisitor<FindMethodsByErasedSig> {
732 private:
733 // Context data
734 Symbol* _method_name;
735 Symbol* _method_signature;
736 StatefulMethodFamily* _family;
738 public:
739 FindMethodsByErasedSig(Symbol* name, Symbol* signature) :
740 _method_name(name), _method_signature(signature),
741 _family(NULL) {}
743 void get_discovered_family(MethodFamily** family) {
744 if (_family != NULL) {
745 *family = _family->get_method_family();
746 } else {
747 *family = NULL;
748 }
749 }
751 void* new_node_data(InstanceKlass* cls) { return new PseudoScope(); }
752 void free_node_data(void* node_data) {
753 PseudoScope::cast(node_data)->destroy();
754 }
756 // Find all methods on this hierarchy that match this
757 // method's erased (name, signature)
758 bool visit() {
759 PseudoScope* scope = PseudoScope::cast(current_data());
760 InstanceKlass* iklass = current_class();
762 Method* m = iklass->find_method(_method_name, _method_signature);
763 if (m != NULL) {
764 if (_family == NULL) {
765 _family = new StatefulMethodFamily();
766 }
768 if (iklass->is_interface()) {
769 StateRestorer* restorer = _family->record_method_and_dq_further(m);
770 scope->add_mark(restorer);
771 } else {
772 // This is the rule that methods in classes "win" (bad word) over
773 // methods in interfaces. This works because of single inheritance
774 _family->set_target_if_empty(m);
775 }
776 }
777 return true;
778 }
780 };
782 // Iterates over the type hierarchy looking for all methods with a specific
783 // method name. The result of this is a set of method families each of
784 // which is populated with a set of methods that implement the same
785 // language-level signature.
786 class FindMethodsByGenericSig : public HierarchyVisitor<FindMethodsByGenericSig> {
787 private:
788 // Context data
789 Thread* THREAD;
790 generic::DescriptorCache* _cache;
791 Symbol* _method_name;
792 generic::Context* _ctx;
793 StatefulGenericMethodFamilies _families;
795 public:
797 FindMethodsByGenericSig(generic::DescriptorCache* cache, Symbol* name,
798 generic::Context* ctx, Thread* thread) :
799 _cache(cache), _method_name(name), _ctx(ctx), THREAD(thread) {}
801 void get_discovered_families(GrowableArray<GenericMethodFamily*>* methods) {
802 _families.extract_families_into(methods);
803 }
805 void* new_node_data(InstanceKlass* cls) { return new PseudoScope(); }
806 void free_node_data(void* node_data) {
807 PseudoScope::cast(node_data)->destroy();
808 }
810 bool visit() {
811 PseudoScope* scope = PseudoScope::cast(current_data());
812 InstanceKlass* klass = current_class();
813 InstanceKlass* sub = current_depth() > 0 ? class_at_depth(1) : NULL;
815 ContextMark* cm = new ContextMark(_ctx->mark());
816 scope->add_mark(cm); // will restore context when scope is freed
818 _ctx->apply_type_arguments(sub, klass, THREAD);
820 int start, end = 0;
821 start = klass->find_method_by_name(_method_name, &end);
822 if (start != -1) {
823 for (int i = start; i < end; ++i) {
824 Method* m = klass->methods()->at(i);
825 // This gets the method's parameter list with its generic type
826 // parameters resolved
827 generic::MethodDescriptor* md = _cache->descriptor_for(m, THREAD);
829 // Find all methods on this hierarchy that match this method
830 // (name, signature). This class collects other families of this
831 // method name.
832 StatefulGenericMethodFamily* family =
833 _families.find_matching_or_create(md, _ctx);
835 if (klass->is_interface()) {
836 // ???
837 StateRestorer* restorer = family->record_method_and_dq_further(m);
838 scope->add_mark(restorer);
839 } else {
840 // This is the rule that methods in classes "win" (bad word) over
841 // methods in interfaces. This works because of single inheritance
842 family->set_target_if_empty(m);
843 }
844 }
845 }
846 return true;
847 }
848 };
850 #ifndef PRODUCT
851 static void print_generic_families(
852 GrowableArray<GenericMethodFamily*>* methods, Symbol* match) {
853 streamIndentor si(tty, 4);
854 if (methods->length() == 0) {
855 tty->indent();
856 tty->print_cr("No Logical Method found");
857 }
858 for (int i = 0; i < methods->length(); ++i) {
859 tty->indent();
860 GenericMethodFamily* lm = methods->at(i);
861 if (lm->contains_signature(match)) {
862 tty->print_cr("<Matching>");
863 } else {
864 tty->print_cr("<Non-Matching>");
865 }
866 lm->print_sig_on(tty, lm->get_generic_sig(), 1);
867 }
868 }
869 #endif // ndef PRODUCT
871 static void create_overpasses(
872 GrowableArray<EmptyVtableSlot*>* slots, InstanceKlass* klass, TRAPS);
874 static void generate_generic_defaults(
875 InstanceKlass* klass, GrowableArray<EmptyVtableSlot*>* empty_slots,
876 EmptyVtableSlot* slot, int current_slot_index, TRAPS) {
878 if (slot->is_bound()) {
879 #ifndef PRODUCT
880 if (TraceDefaultMethods) {
881 streamIndentor si(tty, 4);
882 tty->indent().print_cr("Already bound to logical method:");
883 GenericMethodFamily* lm = (GenericMethodFamily*)(slot->get_binding());
884 lm->print_sig_on(tty, lm->get_generic_sig(), 1);
885 }
886 #endif // ndef PRODUCT
887 return; // covered by previous processing
888 }
890 generic::DescriptorCache cache;
892 generic::Context ctx(&cache);
893 FindMethodsByGenericSig visitor(&cache, slot->name(), &ctx, CHECK);
894 visitor.run(klass);
896 GrowableArray<GenericMethodFamily*> discovered_families;
897 visitor.get_discovered_families(&discovered_families);
899 #ifndef PRODUCT
900 if (TraceDefaultMethods) {
901 print_generic_families(&discovered_families, slot->signature());
902 }
903 #endif // ndef PRODUCT
905 // Find and populate any other slots that match the discovered families
906 for (int j = current_slot_index; j < empty_slots->length(); ++j) {
907 EmptyVtableSlot* open_slot = empty_slots->at(j);
909 if (slot->name() == open_slot->name()) {
910 for (int k = 0; k < discovered_families.length(); ++k) {
911 GenericMethodFamily* lm = discovered_families.at(k);
913 if (lm->contains_signature(open_slot->signature())) {
914 lm->determine_target(klass, CHECK);
915 open_slot->bind_family(lm);
916 }
917 }
918 }
919 }
920 }
922 static void generate_erased_defaults(
923 InstanceKlass* klass, GrowableArray<EmptyVtableSlot*>* empty_slots,
924 EmptyVtableSlot* slot, TRAPS) {
926 // sets up a set of methods with the same exact erased signature
927 FindMethodsByErasedSig visitor(slot->name(), slot->signature());
928 visitor.run(klass);
930 MethodFamily* family;
931 visitor.get_discovered_family(&family);
932 if (family != NULL) {
933 family->determine_target(klass, CHECK);
934 slot->bind_family(family);
935 }
936 }
938 static void merge_in_new_methods(InstanceKlass* klass,
939 GrowableArray<Method*>* new_methods, TRAPS);
941 // This is the guts of the default methods implementation. This is called just
942 // after the classfile has been parsed if some ancestor has default methods.
943 //
944 // First if finds any name/signature slots that need any implementation (either
945 // because they are miranda or a superclass's implementation is an overpass
946 // itself). For each slot, iterate over the hierarchy, using generic signature
947 // information to partition any methods that match the name into method families
948 // where each family contains methods whose signatures are equivalent at the
949 // language level (i.e., their reified parameters match and return values are
950 // covariant). Check those sets to see if they contain a signature that matches
951 // the slot we're looking at (if we're lucky, there might be other empty slots
952 // that we can fill using the same analysis).
953 //
954 // For each slot filled, we generate an overpass method that either calls the
955 // unique default method candidate using invokespecial, or throws an exception
956 // (in the case of no default method candidates, or more than one valid
957 // candidate). These methods are then added to the class's method list. If
958 // the method set we're using contains methods (qualified or not) with a
959 // different runtime signature than the method we're creating, then we have to
960 // create bridges with those signatures too.
961 void DefaultMethods::generate_default_methods(
962 InstanceKlass* klass, GrowableArray<Method*>* mirandas, TRAPS) {
964 // This resource mark is the bound for all memory allocation that takes
965 // place during default method processing. After this goes out of scope,
966 // all (Resource) objects' memory will be reclaimed. Be careful if adding an
967 // embedded resource mark under here as that memory can't be used outside
968 // whatever scope it's in.
969 ResourceMark rm(THREAD);
971 // Keep entire hierarchy alive for the duration of the computation
972 KeepAliveRegistrar keepAlive(THREAD);
973 KeepAliveVisitor loadKeepAlive(&keepAlive);
974 loadKeepAlive.run(klass);
976 #ifndef PRODUCT
977 if (TraceDefaultMethods) {
978 ResourceMark rm; // be careful with these!
979 tty->print_cr("Class %s requires default method processing",
980 klass->name()->as_klass_external_name());
981 PrintHierarchy printer;
982 printer.run(klass);
983 }
984 #endif // ndef PRODUCT
986 GrowableArray<EmptyVtableSlot*>* empty_slots =
987 find_empty_vtable_slots(klass, mirandas, CHECK);
989 for (int i = 0; i < empty_slots->length(); ++i) {
990 EmptyVtableSlot* slot = empty_slots->at(i);
991 #ifndef PRODUCT
992 if (TraceDefaultMethods) {
993 streamIndentor si(tty, 2);
994 tty->indent().print("Looking for default methods for slot ");
995 slot->print_on(tty);
996 tty->print_cr("");
997 }
998 #endif // ndef PRODUCT
1000 if (ParseGenericDefaults) {
1001 generate_generic_defaults(klass, empty_slots, slot, i, CHECK);
1002 } else {
1003 generate_erased_defaults(klass, empty_slots, slot, CHECK);
1004 }
1005 }
1006 #ifndef PRODUCT
1007 if (TraceDefaultMethods) {
1008 tty->print_cr("Creating overpasses...");
1009 }
1010 #endif // ndef PRODUCT
1012 create_overpasses(empty_slots, klass, CHECK);
1014 #ifndef PRODUCT
1015 if (TraceDefaultMethods) {
1016 tty->print_cr("Default method processing complete");
1017 }
1018 #endif // ndef PRODUCT
1019 }
1021 /**
1022 * Generic analysis was used upon interface '_target' and found a unique
1023 * default method candidate with generic signature '_method_desc'. This
1024 * method is only viable if it would also be in the set of default method
1025 * candidates if we ran a full analysis on the current class.
1026 *
1027 * The only reason that the method would not be in the set of candidates for
1028 * the current class is if that there's another covariantly matching method
1029 * which is "more specific" than the found method -- i.e., one could find a
1030 * path in the interface hierarchy in which the matching method appears
1031 * before we get to '_target'.
1032 *
1033 * In order to determine this, we examine all of the implemented
1034 * interfaces. If we find path that leads to the '_target' interface, then
1035 * we examine that path to see if there are any methods that would shadow
1036 * the selected method along that path.
1037 */
1038 class ShadowChecker : public HierarchyVisitor<ShadowChecker> {
1039 protected:
1040 Thread* THREAD;
1042 InstanceKlass* _target;
1044 Symbol* _method_name;
1045 InstanceKlass* _method_holder;
1046 bool _found_shadow;
1049 public:
1051 ShadowChecker(Thread* thread, Symbol* name, InstanceKlass* holder,
1052 InstanceKlass* target)
1053 : THREAD(thread), _method_name(name), _method_holder(holder),
1054 _target(target), _found_shadow(false) {}
1056 void* new_node_data(InstanceKlass* cls) { return NULL; }
1057 void free_node_data(void* data) { return; }
1059 bool visit() {
1060 InstanceKlass* ik = current_class();
1061 if (ik == _target && current_depth() == 1) {
1062 return false; // This was the specified super -- no need to search it
1063 }
1064 if (ik == _method_holder || ik == _target) {
1065 // We found a path that should be examined to see if it shadows _method
1066 if (path_has_shadow()) {
1067 _found_shadow = true;
1068 cancel_iteration();
1069 }
1070 return false; // no need to continue up hierarchy
1071 }
1072 return true;
1073 }
1075 virtual bool path_has_shadow() = 0;
1076 bool found_shadow() { return _found_shadow; }
1077 };
1079 // Used for Invokespecial.
1080 // Invokespecial is allowed to invoke a concrete interface method
1081 // and can be used to disambuiguate among qualified candidates,
1082 // which are methods in immediate superinterfaces,
1083 // but may not be used to invoke a candidate that would be shadowed
1084 // from the perspective of the caller.
1085 // Invokespecial is also used in the overpass generation today
1086 // We re-run the shadowchecker because we can't distinguish this case,
1087 // but it should return the same answer, since the overpass target
1088 // is now the invokespecial caller.
1089 class ErasedShadowChecker : public ShadowChecker {
1090 private:
1091 bool path_has_shadow() {
1093 for (int i = current_depth() - 1; i > 0; --i) {
1094 InstanceKlass* ik = class_at_depth(i);
1096 if (ik->is_interface()) {
1097 int end;
1098 int start = ik->find_method_by_name(_method_name, &end);
1099 if (start != -1) {
1100 return true;
1101 }
1102 }
1103 }
1104 return false;
1105 }
1106 public:
1108 ErasedShadowChecker(Thread* thread, Symbol* name, InstanceKlass* holder,
1109 InstanceKlass* target)
1110 : ShadowChecker(thread, name, holder, target) {}
1111 };
1113 class GenericShadowChecker : public ShadowChecker {
1114 private:
1115 generic::DescriptorCache* _cache;
1116 generic::MethodDescriptor* _method_desc;
1118 bool path_has_shadow() {
1119 generic::Context ctx(_cache);
1121 for (int i = current_depth() - 1; i > 0; --i) {
1122 InstanceKlass* ik = class_at_depth(i);
1123 InstanceKlass* sub = class_at_depth(i + 1);
1124 ctx.apply_type_arguments(sub, ik, THREAD);
1126 if (ik->is_interface()) {
1127 int end;
1128 int start = ik->find_method_by_name(_method_name, &end);
1129 if (start != -1) {
1130 for (int j = start; j < end; ++j) {
1131 Method* mo = ik->methods()->at(j);
1132 generic::MethodDescriptor* md = _cache->descriptor_for(mo, THREAD);
1133 if (_method_desc->covariant_match(md, &ctx)) {
1134 return true;
1135 }
1136 }
1137 }
1138 }
1139 }
1140 return false;
1141 }
1143 public:
1145 GenericShadowChecker(generic::DescriptorCache* cache, Thread* thread,
1146 Symbol* name, InstanceKlass* holder, generic::MethodDescriptor* desc,
1147 InstanceKlass* target)
1148 : ShadowChecker(thread, name, holder, target) {
1149 _cache = cache;
1150 _method_desc = desc;
1151 }
1152 };
1156 // Find the unique qualified candidate from the perspective of the super_class
1157 // which is the resolved_klass, which must be an immediate superinterface
1158 // of klass
1159 Method* find_erased_super_default(InstanceKlass* current_class, InstanceKlass* super_class, Symbol* method_name, Symbol* sig, TRAPS) {
1161 FindMethodsByErasedSig visitor(method_name, sig);
1162 visitor.run(super_class); // find candidates from resolved_klass
1164 MethodFamily* family;
1165 visitor.get_discovered_family(&family);
1167 if (family != NULL) {
1168 family->determine_target(current_class, CHECK_NULL); // get target from current_class
1169 }
1171 if (family->has_target()) {
1172 Method* target = family->get_selected_target();
1173 InstanceKlass* holder = InstanceKlass::cast(target->method_holder());
1175 // Verify that the identified method is valid from the context of
1176 // the current class, which is the caller class for invokespecial
1177 // link resolution, i.e. ensure there it is not shadowed.
1178 // You can use invokespecial to disambiguate interface methods, but
1179 // you can not use it to skip over an interface method that would shadow it.
1180 ErasedShadowChecker checker(THREAD, target->name(), holder, super_class);
1181 checker.run(current_class);
1183 if (checker.found_shadow()) {
1184 #ifndef PRODUCT
1185 if (TraceDefaultMethods) {
1186 tty->print_cr(" Only candidate found was shadowed.");
1187 }
1188 #endif // ndef PRODUCT
1189 THROW_MSG_(vmSymbols::java_lang_AbstractMethodError(),
1190 "Accessible default method not found", NULL);
1191 } else {
1192 #ifndef PRODUCT
1193 if (TraceDefaultMethods) {
1194 family->print_sig_on(tty, target->signature(), 1);
1195 }
1196 #endif // ndef PRODUCT
1197 return target;
1198 }
1199 } else {
1200 assert(family->throws_exception(), "must have target or throw");
1201 THROW_MSG_(vmSymbols::java_lang_AbstractMethodError(),
1202 family->get_exception_message()->as_C_string(), NULL);
1203 }
1204 }
1206 // super_class is assumed to be the direct super of current_class
1207 Method* find_generic_super_default( InstanceKlass* current_class,
1208 InstanceKlass* super_class,
1209 Symbol* method_name, Symbol* sig, TRAPS) {
1210 generic::DescriptorCache cache;
1211 generic::Context ctx(&cache);
1213 // Prime the initial generic context for current -> super_class
1214 ctx.apply_type_arguments(current_class, super_class, CHECK_NULL);
1216 FindMethodsByGenericSig visitor(&cache, method_name, &ctx, CHECK_NULL);
1217 visitor.run(super_class);
1219 GrowableArray<GenericMethodFamily*> families;
1220 visitor.get_discovered_families(&families);
1222 #ifndef PRODUCT
1223 if (TraceDefaultMethods) {
1224 print_generic_families(&families, sig);
1225 }
1226 #endif // ndef PRODUCT
1228 GenericMethodFamily* selected_family = NULL;
1230 for (int i = 0; i < families.length(); ++i) {
1231 GenericMethodFamily* lm = families.at(i);
1232 if (lm->contains_signature(sig)) {
1233 lm->determine_target(current_class, CHECK_NULL);
1234 selected_family = lm;
1235 }
1236 }
1238 if (selected_family->has_target()) {
1239 Method* target = selected_family->get_selected_target();
1240 InstanceKlass* holder = InstanceKlass::cast(target->method_holder());
1242 // Verify that the identified method is valid from the context of
1243 // the current class
1244 GenericShadowChecker checker(&cache, THREAD, target->name(),
1245 holder, selected_family->descriptor(), super_class);
1246 checker.run(current_class);
1248 if (checker.found_shadow()) {
1249 #ifndef PRODUCT
1250 if (TraceDefaultMethods) {
1251 tty->print_cr(" Only candidate found was shadowed.");
1252 }
1253 #endif // ndef PRODUCT
1254 THROW_MSG_(vmSymbols::java_lang_AbstractMethodError(),
1255 "Accessible default method not found", NULL);
1256 } else {
1257 return target;
1258 }
1259 } else {
1260 assert(selected_family->throws_exception(), "must have target or throw");
1261 THROW_MSG_(vmSymbols::java_lang_AbstractMethodError(),
1262 selected_family->get_exception_message()->as_C_string(), NULL);
1263 }
1264 }
1266 // This is called during linktime when we find an invokespecial call that
1267 // refers to a direct superinterface. It indicates that we should find the
1268 // default method in the hierarchy of that superinterface, and if that method
1269 // would have been a candidate from the point of view of 'this' class, then we
1270 // return that method.
1271 // This logic assumes that the super is a direct superclass of the caller
1272 Method* DefaultMethods::find_super_default(
1273 Klass* cls, Klass* super, Symbol* method_name, Symbol* sig, TRAPS) {
1275 ResourceMark rm(THREAD);
1277 assert(cls != NULL && super != NULL, "Need real classes");
1279 InstanceKlass* current_class = InstanceKlass::cast(cls);
1280 InstanceKlass* super_class = InstanceKlass::cast(super);
1282 // Keep entire hierarchy alive for the duration of the computation
1283 KeepAliveRegistrar keepAlive(THREAD);
1284 KeepAliveVisitor loadKeepAlive(&keepAlive);
1285 loadKeepAlive.run(current_class); // get hierarchy from current class
1287 #ifndef PRODUCT
1288 if (TraceDefaultMethods) {
1289 tty->print_cr("Finding super default method %s.%s%s from %s",
1290 super_class->name()->as_C_string(),
1291 method_name->as_C_string(), sig->as_C_string(),
1292 current_class->name()->as_C_string());
1293 }
1294 #endif // ndef PRODUCT
1296 assert(super_class->is_interface(), "only call for default methods");
1298 Method* target = NULL;
1299 if (ParseGenericDefaults) {
1300 target = find_generic_super_default(current_class, super_class,
1301 method_name, sig, CHECK_NULL);
1302 } else {
1303 target = find_erased_super_default(current_class, super_class,
1304 method_name, sig, CHECK_NULL);
1305 }
1307 #ifndef PRODUCT
1308 if (target != NULL) {
1309 if (TraceDefaultMethods) {
1310 tty->print(" Returning ");
1311 print_method(tty, target, true);
1312 tty->print_cr("");
1313 }
1314 }
1315 #endif // ndef PRODUCT
1316 return target;
1317 }
1319 #ifndef PRODUCT
1320 // Return true is broad type is a covariant return of narrow type
1321 static bool covariant_return_type(BasicType narrow, BasicType broad) {
1322 if (narrow == broad) {
1323 return true;
1324 }
1325 if (broad == T_OBJECT) {
1326 return true;
1327 }
1328 return false;
1329 }
1330 #endif // ndef PRODUCT
1332 static int assemble_redirect(
1333 BytecodeConstantPool* cp, BytecodeBuffer* buffer,
1334 Symbol* incoming, Method* target, TRAPS) {
1336 BytecodeAssembler assem(buffer, cp);
1338 SignatureStream in(incoming, true);
1339 SignatureStream out(target->signature(), true);
1340 u2 parameter_count = 0;
1342 assem.aload(parameter_count++); // load 'this'
1344 while (!in.at_return_type()) {
1345 assert(!out.at_return_type(), "Parameter counts do not match");
1346 BasicType bt = in.type();
1347 assert(out.type() == bt, "Parameter types are not compatible");
1348 assem.load(bt, parameter_count);
1349 if (in.is_object() && in.as_symbol(THREAD) != out.as_symbol(THREAD)) {
1350 assem.checkcast(out.as_symbol(THREAD));
1351 } else if (bt == T_LONG || bt == T_DOUBLE) {
1352 ++parameter_count; // longs and doubles use two slots
1353 }
1354 ++parameter_count;
1355 in.next();
1356 out.next();
1357 }
1358 assert(out.at_return_type(), "Parameter counts do not match");
1359 assert(covariant_return_type(out.type(), in.type()), "Return types are not compatible");
1361 if (parameter_count == 1 && (in.type() == T_LONG || in.type() == T_DOUBLE)) {
1362 ++parameter_count; // need room for return value
1363 }
1364 if (target->method_holder()->is_interface()) {
1365 assem.invokespecial(target);
1366 } else {
1367 assem.invokevirtual(target);
1368 }
1370 if (in.is_object() && in.as_symbol(THREAD) != out.as_symbol(THREAD)) {
1371 assem.checkcast(in.as_symbol(THREAD));
1372 }
1373 assem._return(in.type());
1374 return parameter_count;
1375 }
1377 static int assemble_abstract_method_error(
1378 BytecodeConstantPool* cp, BytecodeBuffer* buffer, Symbol* message, TRAPS) {
1380 Symbol* errorName = vmSymbols::java_lang_AbstractMethodError();
1381 Symbol* init = vmSymbols::object_initializer_name();
1382 Symbol* sig = vmSymbols::string_void_signature();
1384 BytecodeAssembler assem(buffer, cp);
1386 assem._new(errorName);
1387 assem.dup();
1388 assem.load_string(message);
1389 assem.invokespecial(errorName, init, sig);
1390 assem.athrow();
1392 return 3; // max stack size: [ exception, exception, string ]
1393 }
1395 static Method* new_method(
1396 BytecodeConstantPool* cp, BytecodeBuffer* bytecodes, Symbol* name,
1397 Symbol* sig, AccessFlags flags, int max_stack, int params,
1398 ConstMethod::MethodType mt, TRAPS) {
1400 address code_start = 0;
1401 int code_length = 0;
1402 InlineTableSizes sizes;
1404 if (bytecodes != NULL && bytecodes->length() > 0) {
1405 code_start = static_cast<address>(bytecodes->adr_at(0));
1406 code_length = bytecodes->length();
1407 }
1409 Method* m = Method::allocate(cp->pool_holder()->class_loader_data(),
1410 code_length, flags, &sizes,
1411 mt, CHECK_NULL);
1413 m->set_constants(NULL); // This will get filled in later
1414 m->set_name_index(cp->utf8(name));
1415 m->set_signature_index(cp->utf8(sig));
1416 #ifdef CC_INTERP
1417 ResultTypeFinder rtf(sig);
1418 m->set_result_index(rtf.type());
1419 #endif
1420 m->set_size_of_parameters(params);
1421 m->set_max_stack(max_stack);
1422 m->set_max_locals(params);
1423 m->constMethod()->set_stackmap_data(NULL);
1424 m->set_code(code_start);
1425 m->set_force_inline(true);
1427 return m;
1428 }
1430 static void switchover_constant_pool(BytecodeConstantPool* bpool,
1431 InstanceKlass* klass, GrowableArray<Method*>* new_methods, TRAPS) {
1433 if (new_methods->length() > 0) {
1434 ConstantPool* cp = bpool->create_constant_pool(CHECK);
1435 if (cp != klass->constants()) {
1436 klass->class_loader_data()->add_to_deallocate_list(klass->constants());
1437 klass->set_constants(cp);
1438 cp->set_pool_holder(klass);
1440 for (int i = 0; i < new_methods->length(); ++i) {
1441 new_methods->at(i)->set_constants(cp);
1442 }
1443 for (int i = 0; i < klass->methods()->length(); ++i) {
1444 Method* mo = klass->methods()->at(i);
1445 mo->set_constants(cp);
1446 }
1447 }
1448 }
1449 }
1451 // A "bridge" is a method created by javac to bridge the gap between
1452 // an implementation and a generically-compatible, but different, signature.
1453 // Bridges have actual bytecode implementation in classfiles.
1454 // An "overpass", on the other hand, performs the same function as a bridge
1455 // but does not occur in a classfile; the VM creates overpass itself,
1456 // when it needs a path to get from a call site to an default method, and
1457 // a bridge doesn't exist.
1458 static void create_overpasses(
1459 GrowableArray<EmptyVtableSlot*>* slots,
1460 InstanceKlass* klass, TRAPS) {
1462 GrowableArray<Method*> overpasses;
1463 BytecodeConstantPool bpool(klass->constants());
1465 for (int i = 0; i < slots->length(); ++i) {
1466 EmptyVtableSlot* slot = slots->at(i);
1468 if (slot->is_bound()) {
1469 MethodFamily* method = slot->get_binding();
1470 int max_stack = 0;
1471 BytecodeBuffer buffer;
1473 #ifndef PRODUCT
1474 if (TraceDefaultMethods) {
1475 tty->print("for slot: ");
1476 slot->print_on(tty);
1477 tty->print_cr("");
1478 if (method->has_target()) {
1479 method->print_selected(tty, 1);
1480 } else {
1481 method->print_exception(tty, 1);
1482 }
1483 }
1484 #endif // ndef PRODUCT
1485 if (method->has_target()) {
1486 Method* selected = method->get_selected_target();
1487 max_stack = assemble_redirect(
1488 &bpool, &buffer, slot->signature(), selected, CHECK);
1489 } else if (method->throws_exception()) {
1490 max_stack = assemble_abstract_method_error(
1491 &bpool, &buffer, method->get_exception_message(), CHECK);
1492 }
1493 AccessFlags flags = accessFlags_from(
1494 JVM_ACC_PUBLIC | JVM_ACC_SYNTHETIC | JVM_ACC_BRIDGE);
1495 Method* m = new_method(&bpool, &buffer, slot->name(), slot->signature(),
1496 flags, max_stack, slot->size_of_parameters(),
1497 ConstMethod::OVERPASS, CHECK);
1498 if (m != NULL) {
1499 overpasses.push(m);
1500 }
1501 }
1502 }
1504 #ifndef PRODUCT
1505 if (TraceDefaultMethods) {
1506 tty->print_cr("Created %d overpass methods", overpasses.length());
1507 }
1508 #endif // ndef PRODUCT
1510 switchover_constant_pool(&bpool, klass, &overpasses, CHECK);
1511 merge_in_new_methods(klass, &overpasses, CHECK);
1512 }
1514 static void sort_methods(GrowableArray<Method*>* methods) {
1515 // Note that this must sort using the same key as is used for sorting
1516 // methods in InstanceKlass.
1517 bool sorted = true;
1518 for (int i = methods->length() - 1; i > 0; --i) {
1519 for (int j = 0; j < i; ++j) {
1520 Method* m1 = methods->at(j);
1521 Method* m2 = methods->at(j + 1);
1522 if ((uintptr_t)m1->name() > (uintptr_t)m2->name()) {
1523 methods->at_put(j, m2);
1524 methods->at_put(j + 1, m1);
1525 sorted = false;
1526 }
1527 }
1528 if (sorted) break;
1529 sorted = true;
1530 }
1531 #ifdef ASSERT
1532 uintptr_t prev = 0;
1533 for (int i = 0; i < methods->length(); ++i) {
1534 Method* mh = methods->at(i);
1535 uintptr_t nv = (uintptr_t)mh->name();
1536 assert(nv >= prev, "Incorrect overpass method ordering");
1537 prev = nv;
1538 }
1539 #endif
1540 }
1542 static void merge_in_new_methods(InstanceKlass* klass,
1543 GrowableArray<Method*>* new_methods, TRAPS) {
1545 enum { ANNOTATIONS, PARAMETERS, DEFAULTS, NUM_ARRAYS };
1547 Array<Method*>* original_methods = klass->methods();
1548 Array<int>* original_ordering = klass->method_ordering();
1549 Array<int>* merged_ordering = Universe::the_empty_int_array();
1551 int new_size = klass->methods()->length() + new_methods->length();
1553 Array<Method*>* merged_methods = MetadataFactory::new_array<Method*>(
1554 klass->class_loader_data(), new_size, NULL, CHECK);
1556 if (original_ordering != NULL && original_ordering->length() > 0) {
1557 merged_ordering = MetadataFactory::new_array<int>(
1558 klass->class_loader_data(), new_size, CHECK);
1559 }
1560 int method_order_index = klass->methods()->length();
1562 sort_methods(new_methods);
1564 // Perform grand merge of existing methods and new methods
1565 int orig_idx = 0;
1566 int new_idx = 0;
1568 for (int i = 0; i < new_size; ++i) {
1569 Method* orig_method = NULL;
1570 Method* new_method = NULL;
1571 if (orig_idx < original_methods->length()) {
1572 orig_method = original_methods->at(orig_idx);
1573 }
1574 if (new_idx < new_methods->length()) {
1575 new_method = new_methods->at(new_idx);
1576 }
1578 if (orig_method != NULL &&
1579 (new_method == NULL || orig_method->name() < new_method->name())) {
1580 merged_methods->at_put(i, orig_method);
1581 original_methods->at_put(orig_idx, NULL);
1582 if (merged_ordering->length() > 0) {
1583 merged_ordering->at_put(i, original_ordering->at(orig_idx));
1584 }
1585 ++orig_idx;
1586 } else {
1587 merged_methods->at_put(i, new_method);
1588 if (merged_ordering->length() > 0) {
1589 merged_ordering->at_put(i, method_order_index++);
1590 }
1591 ++new_idx;
1592 }
1593 // update idnum for new location
1594 merged_methods->at(i)->set_method_idnum(i);
1595 }
1597 // Verify correct order
1598 #ifdef ASSERT
1599 uintptr_t prev = 0;
1600 for (int i = 0; i < merged_methods->length(); ++i) {
1601 Method* mo = merged_methods->at(i);
1602 uintptr_t nv = (uintptr_t)mo->name();
1603 assert(nv >= prev, "Incorrect method ordering");
1604 prev = nv;
1605 }
1606 #endif
1608 // Replace klass methods with new merged lists
1609 klass->set_methods(merged_methods);
1610 klass->set_initial_method_idnum(new_size);
1612 ClassLoaderData* cld = klass->class_loader_data();
1613 MetadataFactory::free_array(cld, original_methods);
1614 if (original_ordering->length() > 0) {
1615 klass->set_method_ordering(merged_ordering);
1616 MetadataFactory::free_array(cld, original_ordering);
1617 }
1618 }