1 /*
2 * Copyright (c) 1999, 2010, 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 "incls/_precompiled.incl"
26 #include "incls/_ciInstanceKlass.cpp.incl"
27
28 // ciInstanceKlass
29 //
30 // This class represents a klassOop in the HotSpot virtual machine
31 // whose Klass part in an instanceKlass.
32
33 // ------------------------------------------------------------------
34 // ciInstanceKlass::ciInstanceKlass
35 //
36 // Loaded instance klass.
37 ciInstanceKlass::ciInstanceKlass(KlassHandle h_k) :
38 ciKlass(h_k), _non_static_fields(NULL)
39 {
40 assert(get_Klass()->oop_is_instance(), "wrong type");
41 instanceKlass* ik = get_instanceKlass();
42
43 AccessFlags access_flags = ik->access_flags();
44 _flags = ciFlags(access_flags);
45 _has_finalizer = access_flags.has_finalizer();
46 _has_subklass = ik->subklass() != NULL;
47 _init_state = (instanceKlass::ClassState)ik->get_init_state();
48 _nonstatic_field_size = ik->nonstatic_field_size();
49 _has_nonstatic_fields = ik->has_nonstatic_fields();
50 _nonstatic_fields = NULL; // initialized lazily by compute_nonstatic_fields:
51
52 _nof_implementors = ik->nof_implementors();
53 for (int i = 0; i < implementors_limit; i++) {
54 _implementors[i] = NULL; // we will fill these lazily
55 }
56
57 Thread *thread = Thread::current();
58 if (ciObjectFactory::is_initialized()) {
59 _loader = JNIHandles::make_local(thread, ik->class_loader());
60 _protection_domain = JNIHandles::make_local(thread,
61 ik->protection_domain());
62 _is_shared = false;
63 } else {
64 Handle h_loader(thread, ik->class_loader());
65 Handle h_protection_domain(thread, ik->protection_domain());
66 _loader = JNIHandles::make_global(h_loader);
67 _protection_domain = JNIHandles::make_global(h_protection_domain);
68 _is_shared = true;
69 }
70
71 // Lazy fields get filled in only upon request.
72 _super = NULL;
73 _java_mirror = NULL;
74
75 if (is_shared()) {
76 if (h_k() != SystemDictionary::Object_klass()) {
77 super();
78 }
79 java_mirror();
80 //compute_nonstatic_fields(); // done outside of constructor
81 }
82
83 _field_cache = NULL;
84 }
85
86 // Version for unloaded classes:
87 ciInstanceKlass::ciInstanceKlass(ciSymbol* name,
88 jobject loader, jobject protection_domain)
89 : ciKlass(name, ciInstanceKlassKlass::make())
90 {
91 assert(name->byte_at(0) != '[', "not an instance klass");
92 _init_state = (instanceKlass::ClassState)0;
93 _nonstatic_field_size = -1;
94 _has_nonstatic_fields = false;
95 _nonstatic_fields = NULL;
96 _nof_implementors = -1;
97 _loader = loader;
98 _protection_domain = protection_domain;
99 _is_shared = false;
100 _super = NULL;
101 _java_mirror = NULL;
102 _field_cache = NULL;
103 }
104
105
106
107 // ------------------------------------------------------------------
108 // ciInstanceKlass::compute_shared_is_initialized
109 void ciInstanceKlass::compute_shared_init_state() {
110 GUARDED_VM_ENTRY(
111 instanceKlass* ik = get_instanceKlass();
112 _init_state = (instanceKlass::ClassState)ik->get_init_state();
113 )
114 }
115
116 // ------------------------------------------------------------------
117 // ciInstanceKlass::compute_shared_has_subklass
118 bool ciInstanceKlass::compute_shared_has_subklass() {
119 GUARDED_VM_ENTRY(
120 instanceKlass* ik = get_instanceKlass();
121 _has_subklass = ik->subklass() != NULL;
122 return _has_subklass;
123 )
124 }
125
126 // ------------------------------------------------------------------
127 // ciInstanceKlass::compute_shared_nof_implementors
128 int ciInstanceKlass::compute_shared_nof_implementors() {
129 // We requery this property, since it is a very old ciObject.
130 GUARDED_VM_ENTRY(
131 instanceKlass* ik = get_instanceKlass();
132 _nof_implementors = ik->nof_implementors();
133 return _nof_implementors;
134 )
135 }
136
137 // ------------------------------------------------------------------
138 // ciInstanceKlass::loader
139 oop ciInstanceKlass::loader() {
140 ASSERT_IN_VM;
141 return JNIHandles::resolve(_loader);
142 }
143
144 // ------------------------------------------------------------------
145 // ciInstanceKlass::loader_handle
146 jobject ciInstanceKlass::loader_handle() {
147 return _loader;
148 }
149
150 // ------------------------------------------------------------------
151 // ciInstanceKlass::protection_domain
152 oop ciInstanceKlass::protection_domain() {
153 ASSERT_IN_VM;
154 return JNIHandles::resolve(_protection_domain);
155 }
156
157 // ------------------------------------------------------------------
158 // ciInstanceKlass::protection_domain_handle
159 jobject ciInstanceKlass::protection_domain_handle() {
160 return _protection_domain;
161 }
162
163 // ------------------------------------------------------------------
164 // ciInstanceKlass::field_cache
165 //
166 // Get the field cache associated with this klass.
167 ciConstantPoolCache* ciInstanceKlass::field_cache() {
168 if (is_shared()) {
169 return NULL;
170 }
171 if (_field_cache == NULL) {
172 assert(!is_java_lang_Object(), "Object has no fields");
173 Arena* arena = CURRENT_ENV->arena();
174 _field_cache = new (arena) ciConstantPoolCache(arena, 5);
175 }
176 return _field_cache;
177 }
178
179 // ------------------------------------------------------------------
180 // ciInstanceKlass::get_canonical_holder
181 //
182 ciInstanceKlass* ciInstanceKlass::get_canonical_holder(int offset) {
183 #ifdef ASSERT
184 if (!(offset >= 0 && offset < layout_helper())) {
185 tty->print("*** get_canonical_holder(%d) on ", offset);
186 this->print();
187 tty->print_cr(" ***");
188 };
189 assert(offset >= 0 && offset < layout_helper(), "offset must be tame");
190 #endif
191
192 if (offset < instanceOopDesc::base_offset_in_bytes()) {
193 // All header offsets belong properly to java/lang/Object.
194 return CURRENT_ENV->Object_klass();
195 }
196
197 ciInstanceKlass* self = this;
198 for (;;) {
199 assert(self->is_loaded(), "must be loaded to have size");
200 ciInstanceKlass* super = self->super();
201 if (super == NULL || super->nof_nonstatic_fields() == 0 ||
202 !super->contains_field_offset(offset)) {
203 return self;
204 } else {
205 self = super; // return super->get_canonical_holder(offset)
206 }
207 }
208 }
209
210 // ------------------------------------------------------------------
211 // ciInstanceKlass::is_java_lang_Object
212 //
213 // Is this klass java.lang.Object?
214 bool ciInstanceKlass::is_java_lang_Object() {
215 return equals(CURRENT_ENV->Object_klass());
216 }
217
218 // ------------------------------------------------------------------
219 // ciInstanceKlass::uses_default_loader
220 bool ciInstanceKlass::uses_default_loader() {
221 // Note: We do not need to resolve the handle or enter the VM
222 // in order to test null-ness.
223 return _loader == NULL;
224 }
225
226 // ------------------------------------------------------------------
227 // ciInstanceKlass::is_in_package
228 //
229 // Is this klass in the given package?
230 bool ciInstanceKlass::is_in_package(const char* packagename, int len) {
231 // To avoid class loader mischief, this test always rejects application classes.
232 if (!uses_default_loader())
233 return false;
234 GUARDED_VM_ENTRY(
235 return is_in_package_impl(packagename, len);
236 )
237 }
238
239 bool ciInstanceKlass::is_in_package_impl(const char* packagename, int len) {
240 ASSERT_IN_VM;
241
242 // If packagename contains trailing '/' exclude it from the
243 // prefix-test since we test for it explicitly.
244 if (packagename[len - 1] == '/')
245 len--;
246
247 if (!name()->starts_with(packagename, len))
248 return false;
249
250 // Test if the class name is something like "java/lang".
251 if ((len + 1) > name()->utf8_length())
252 return false;
253
254 // Test for trailing '/'
255 if ((char) name()->byte_at(len) != '/')
256 return false;
257
258 // Make sure it's not actually in a subpackage:
259 if (name()->index_of_at(len+1, "/", 1) >= 0)
260 return false;
261
262 return true;
263 }
264
265 // ------------------------------------------------------------------
266 // ciInstanceKlass::print_impl
267 //
268 // Implementation of the print method.
269 void ciInstanceKlass::print_impl(outputStream* st) {
270 ciKlass::print_impl(st);
271 GUARDED_VM_ENTRY(st->print(" loader=0x%x", (address)loader());)
272 if (is_loaded()) {
273 st->print(" loaded=true initialized=%s finalized=%s subklass=%s size=%d flags=",
274 bool_to_str(is_initialized()),
275 bool_to_str(has_finalizer()),
276 bool_to_str(has_subklass()),
277 layout_helper());
278
279 _flags.print_klass_flags();
280
281 if (_super) {
282 st->print(" super=");
283 _super->print_name();
284 }
285 if (_java_mirror) {
286 st->print(" mirror=PRESENT");
287 }
288 } else {
289 st->print(" loaded=false");
290 }
291 }
292
293 // ------------------------------------------------------------------
294 // ciInstanceKlass::super
295 //
296 // Get the superklass of this klass.
297 ciInstanceKlass* ciInstanceKlass::super() {
298 assert(is_loaded(), "must be loaded");
299 if (_super == NULL && !is_java_lang_Object()) {
300 GUARDED_VM_ENTRY(
301 klassOop super_klass = get_instanceKlass()->super();
302 _super = CURRENT_ENV->get_object(super_klass)->as_instance_klass();
303 )
304 }
305 return _super;
306 }
307
308 // ------------------------------------------------------------------
309 // ciInstanceKlass::java_mirror
310 //
311 // Get the instance of java.lang.Class corresponding to this klass.
312 // Cache it on this->_java_mirror.
313 ciInstance* ciInstanceKlass::java_mirror() {
314 if (_java_mirror == NULL) {
315 _java_mirror = ciKlass::java_mirror();
316 }
317 return _java_mirror;
318 }
319
320 // ------------------------------------------------------------------
321 // ciInstanceKlass::unique_concrete_subklass
322 ciInstanceKlass* ciInstanceKlass::unique_concrete_subklass() {
323 if (!is_loaded()) return NULL; // No change if class is not loaded
324 if (!is_abstract()) return NULL; // Only applies to abstract classes.
325 if (!has_subklass()) return NULL; // Must have at least one subklass.
326 VM_ENTRY_MARK;
327 instanceKlass* ik = get_instanceKlass();
328 Klass* up = ik->up_cast_abstract();
329 assert(up->oop_is_instance(), "must be instanceKlass");
330 if (ik == up) {
331 return NULL;
332 }
333 return CURRENT_THREAD_ENV->get_object(up->as_klassOop())->as_instance_klass();
334 }
335
336 // ------------------------------------------------------------------
337 // ciInstanceKlass::has_finalizable_subclass
338 bool ciInstanceKlass::has_finalizable_subclass() {
339 if (!is_loaded()) return true;
340 VM_ENTRY_MARK;
341 return Dependencies::find_finalizable_subclass(get_instanceKlass()) != NULL;
342 }
343
344 // ------------------------------------------------------------------
345 // ciInstanceKlass::get_field_by_offset
346 ciField* ciInstanceKlass::get_field_by_offset(int field_offset, bool is_static) {
347 if (!is_static) {
348 for (int i = 0, len = nof_nonstatic_fields(); i < len; i++) {
349 ciField* field = _nonstatic_fields->at(i);
350 int field_off = field->offset_in_bytes();
351 if (field_off == field_offset)
352 return field;
353 if (field_off > field_offset)
354 break;
355 // could do binary search or check bins, but probably not worth it
356 }
357 return NULL;
358 }
359 VM_ENTRY_MARK;
360 instanceKlass* k = get_instanceKlass();
361 fieldDescriptor fd;
362 if (!k->find_field_from_offset(field_offset, is_static, &fd)) {
363 return NULL;
364 }
365 ciField* field = new (CURRENT_THREAD_ENV->arena()) ciField(&fd);
366 return field;
367 }
368
369 // ------------------------------------------------------------------
370 // ciInstanceKlass::get_field_by_name
371 ciField* ciInstanceKlass::get_field_by_name(ciSymbol* name, ciSymbol* signature, bool is_static) {
372 VM_ENTRY_MARK;
373 instanceKlass* k = get_instanceKlass();
374 fieldDescriptor fd;
375 klassOop def = k->find_field(name->get_symbolOop(), signature->get_symbolOop(), is_static, &fd);
376 if (def == NULL) {
377 return NULL;
378 }
379 ciField* field = new (CURRENT_THREAD_ENV->arena()) ciField(&fd);
380 return field;
381 }
382
383 // ------------------------------------------------------------------
384 // ciInstanceKlass::non_static_fields.
385
386 class NonStaticFieldFiller: public FieldClosure {
387 GrowableArray<ciField*>* _arr;
388 ciEnv* _curEnv;
389 public:
390 NonStaticFieldFiller(ciEnv* curEnv, GrowableArray<ciField*>* arr) :
391 _curEnv(curEnv), _arr(arr)
392 {}
393 void do_field(fieldDescriptor* fd) {
394 ciField* field = new (_curEnv->arena()) ciField(fd);
395 _arr->append(field);
396 }
397 };
398
399 GrowableArray<ciField*>* ciInstanceKlass::non_static_fields() {
400 if (_non_static_fields == NULL) {
401 VM_ENTRY_MARK;
402 ciEnv* curEnv = ciEnv::current();
403 instanceKlass* ik = get_instanceKlass();
404 int max_n_fields = ik->fields()->length()/instanceKlass::next_offset;
405
406 Arena* arena = curEnv->arena();
407 _non_static_fields =
408 new (arena) GrowableArray<ciField*>(arena, max_n_fields, 0, NULL);
409 NonStaticFieldFiller filler(curEnv, _non_static_fields);
410 ik->do_nonstatic_fields(&filler);
411 }
412 return _non_static_fields;
413 }
414
415 static int sort_field_by_offset(ciField** a, ciField** b) {
416 return (*a)->offset_in_bytes() - (*b)->offset_in_bytes();
417 // (no worries about 32-bit overflow...)
418 }
419
420 // ------------------------------------------------------------------
421 // ciInstanceKlass::compute_nonstatic_fields
422 int ciInstanceKlass::compute_nonstatic_fields() {
423 assert(is_loaded(), "must be loaded");
424
425 if (_nonstatic_fields != NULL)
426 return _nonstatic_fields->length();
427
428 if (!has_nonstatic_fields()) {
429 Arena* arena = CURRENT_ENV->arena();
430 _nonstatic_fields = new (arena) GrowableArray<ciField*>(arena, 0, 0, NULL);
431 return 0;
432 }
433 assert(!is_java_lang_Object(), "bootstrap OK");
434
435 // Size in bytes of my fields, including inherited fields.
436 int fsize = nonstatic_field_size() * heapOopSize;
437
438 ciInstanceKlass* super = this->super();
439 GrowableArray<ciField*>* super_fields = NULL;
440 if (super != NULL && super->has_nonstatic_fields()) {
441 int super_fsize = super->nonstatic_field_size() * heapOopSize;
442 int super_flen = super->nof_nonstatic_fields();
443 super_fields = super->_nonstatic_fields;
444 assert(super_flen == 0 || super_fields != NULL, "first get nof_fields");
445 // See if I am no larger than my super; if so, I can use his fields.
446 if (fsize == super_fsize) {
447 _nonstatic_fields = super_fields;
448 return super_fields->length();
449 }
450 }
451
452 GrowableArray<ciField*>* fields = NULL;
453 GUARDED_VM_ENTRY({
454 fields = compute_nonstatic_fields_impl(super_fields);
455 });
456
457 if (fields == NULL) {
458 // This can happen if this class (java.lang.Class) has invisible fields.
459 _nonstatic_fields = super_fields;
460 return super_fields->length();
461 }
462
463 int flen = fields->length();
464
465 // Now sort them by offset, ascending.
466 // (In principle, they could mix with superclass fields.)
467 fields->sort(sort_field_by_offset);
468 #ifdef ASSERT
469 int last_offset = instanceOopDesc::base_offset_in_bytes();
470 for (int i = 0; i < fields->length(); i++) {
471 ciField* field = fields->at(i);
472 int offset = field->offset_in_bytes();
473 int size = (field->_type == NULL) ? heapOopSize : field->size_in_bytes();
474 assert(last_offset <= offset, "no field overlap");
475 if (last_offset > (int)sizeof(oopDesc))
476 assert((offset - last_offset) < BytesPerLong, "no big holes");
477 // Note: Two consecutive T_BYTE fields will be separated by wordSize-1
478 // padding bytes if one of them is declared by a superclass.
479 // This is a minor inefficiency classFileParser.cpp.
480 last_offset = offset + size;
481 }
482 assert(last_offset <= (int)instanceOopDesc::base_offset_in_bytes() + fsize, "no overflow");
483 #endif
484
485 _nonstatic_fields = fields;
486 return flen;
487 }
488
489 GrowableArray<ciField*>*
490 ciInstanceKlass::compute_nonstatic_fields_impl(GrowableArray<ciField*>*
491 super_fields) {
492 ASSERT_IN_VM;
493 Arena* arena = CURRENT_ENV->arena();
494 int flen = 0;
495 GrowableArray<ciField*>* fields = NULL;
496 instanceKlass* k = get_instanceKlass();
497 typeArrayOop fields_array = k->fields();
498 for (int pass = 0; pass <= 1; pass++) {
499 for (int i = 0, alen = fields_array->length(); i < alen; i += instanceKlass::next_offset) {
500 fieldDescriptor fd;
501 fd.initialize(k->as_klassOop(), i);
502 if (fd.is_static()) continue;
503 if (pass == 0) {
504 flen += 1;
505 } else {
506 ciField* field = new (arena) ciField(&fd);
507 fields->append(field);
508 }
509 }
510
511 // Between passes, allocate the array:
512 if (pass == 0) {
513 if (flen == 0) {
514 return NULL; // return nothing if none are locally declared
515 }
516 if (super_fields != NULL) {
517 flen += super_fields->length();
518 }
519 fields = new (arena) GrowableArray<ciField*>(arena, flen, 0, NULL);
520 if (super_fields != NULL) {
521 fields->appendAll(super_fields);
522 }
523 }
524 }
525 assert(fields->length() == flen, "sanity");
526 return fields;
527 }
528
529 // ------------------------------------------------------------------
530 // ciInstanceKlass::find_method
531 //
532 // Find a method in this klass.
533 ciMethod* ciInstanceKlass::find_method(ciSymbol* name, ciSymbol* signature) {
534 VM_ENTRY_MARK;
535 instanceKlass* k = get_instanceKlass();
536 symbolOop name_sym = name->get_symbolOop();
537 symbolOop sig_sym= signature->get_symbolOop();
538
539 methodOop m = k->find_method(name_sym, sig_sym);
540 if (m == NULL) return NULL;
541
542 return CURRENT_THREAD_ENV->get_object(m)->as_method();
543 }
544
545 // ------------------------------------------------------------------
546 // ciInstanceKlass::is_leaf_type
547 bool ciInstanceKlass::is_leaf_type() {
548 assert(is_loaded(), "must be loaded");
549 if (is_shared()) {
550 return is_final(); // approximately correct
551 } else {
552 return !_has_subklass && (_nof_implementors == 0);
553 }
554 }
555
556 // ------------------------------------------------------------------
557 // ciInstanceKlass::implementor
558 //
559 // Report an implementor of this interface.
560 // Returns NULL if exact information is not available.
561 // Note that there are various races here, since my copy
562 // of _nof_implementors might be out of date with respect
563 // to results returned by instanceKlass::implementor.
564 // This is OK, since any dependencies we decide to assert
565 // will be checked later under the Compile_lock.
566 ciInstanceKlass* ciInstanceKlass::implementor(int n) {
567 if (n > implementors_limit) {
568 return NULL;
569 }
570 ciInstanceKlass* impl = _implementors[n];
571 if (impl == NULL) {
572 if (_nof_implementors > implementors_limit) {
573 return NULL;
574 }
575 // Go into the VM to fetch the implementor.
576 {
577 VM_ENTRY_MARK;
578 klassOop k = get_instanceKlass()->implementor(n);
579 if (k != NULL) {
580 impl = CURRENT_THREAD_ENV->get_object(k)->as_instance_klass();
581 }
582 }
583 // Memoize this result.
584 if (!is_shared()) {
585 _implementors[n] = (impl == NULL)? this: impl;
586 }
587 } else if (impl == this) {
588 impl = NULL; // memoized null result from a VM query
589 }
590 return impl;
591 }