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 "precompiled.hpp"
26 #include "ci/ciField.hpp"
27 #include "ci/ciInstance.hpp"
28 #include "ci/ciInstanceKlass.hpp"
29 #include "ci/ciUtilities.hpp"
30 #include "classfile/systemDictionary.hpp"
31 #include "memory/allocation.hpp"
32 #include "memory/allocation.inline.hpp"
33 #include "oops/oop.inline.hpp"
34 #include "runtime/fieldDescriptor.hpp"
35
36 // ciInstanceKlass
37 //
38 // This class represents a klassOop in the HotSpot virtual machine
39 // whose Klass part in an instanceKlass.
40
41 // ------------------------------------------------------------------
42 // ciInstanceKlass::ciInstanceKlass
43 //
44 // Loaded instance klass.
45 ciInstanceKlass::ciInstanceKlass(KlassHandle h_k) :
46 ciKlass(h_k), _non_static_fields(NULL)
47 {
48 assert(get_Klass()->oop_is_instance(), "wrong type");
49 assert(get_instanceKlass()->is_loaded(), "must be at least loaded");
50 instanceKlass* ik = get_instanceKlass();
51
52 AccessFlags access_flags = ik->access_flags();
53 _flags = ciFlags(access_flags);
54 _has_finalizer = access_flags.has_finalizer();
55 _has_subklass = ik->subklass() != NULL;
56 _init_state = (instanceKlass::ClassState)ik->get_init_state();
57 _nonstatic_field_size = ik->nonstatic_field_size();
58 _has_nonstatic_fields = ik->has_nonstatic_fields();
59 _nonstatic_fields = NULL; // initialized lazily by compute_nonstatic_fields:
60
61 _nof_implementors = ik->nof_implementors();
62 for (int i = 0; i < implementors_limit; i++) {
63 _implementors[i] = NULL; // we will fill these lazily
64 }
65
66 Thread *thread = Thread::current();
67 if (ciObjectFactory::is_initialized()) {
68 _loader = JNIHandles::make_local(thread, ik->class_loader());
69 _protection_domain = JNIHandles::make_local(thread,
70 ik->protection_domain());
71 _is_shared = false;
72 } else {
73 Handle h_loader(thread, ik->class_loader());
74 Handle h_protection_domain(thread, ik->protection_domain());
75 _loader = JNIHandles::make_global(h_loader);
76 _protection_domain = JNIHandles::make_global(h_protection_domain);
77 _is_shared = true;
78 }
79
80 // Lazy fields get filled in only upon request.
81 _super = NULL;
82 _java_mirror = NULL;
83
84 if (is_shared()) {
85 if (h_k() != SystemDictionary::Object_klass()) {
86 super();
87 }
88 java_mirror();
89 //compute_nonstatic_fields(); // done outside of constructor
90 }
91
92 _field_cache = NULL;
93 }
94
95 // Version for unloaded classes:
96 ciInstanceKlass::ciInstanceKlass(ciSymbol* name,
97 jobject loader, jobject protection_domain)
98 : ciKlass(name, ciInstanceKlassKlass::make())
99 {
100 assert(name->byte_at(0) != '[', "not an instance klass");
101 _init_state = (instanceKlass::ClassState)0;
102 _nonstatic_field_size = -1;
103 _has_nonstatic_fields = false;
104 _nonstatic_fields = NULL;
105 _nof_implementors = -1;
106 _loader = loader;
107 _protection_domain = protection_domain;
108 _is_shared = false;
109 _super = NULL;
110 _java_mirror = NULL;
111 _field_cache = NULL;
112 }
113
114
115
116 // ------------------------------------------------------------------
117 // ciInstanceKlass::compute_shared_is_initialized
118 void ciInstanceKlass::compute_shared_init_state() {
119 GUARDED_VM_ENTRY(
120 instanceKlass* ik = get_instanceKlass();
121 _init_state = (instanceKlass::ClassState)ik->get_init_state();
122 )
123 }
124
125 // ------------------------------------------------------------------
126 // ciInstanceKlass::compute_shared_has_subklass
127 bool ciInstanceKlass::compute_shared_has_subklass() {
128 GUARDED_VM_ENTRY(
129 instanceKlass* ik = get_instanceKlass();
130 _has_subklass = ik->subklass() != NULL;
131 return _has_subklass;
132 )
133 }
134
135 // ------------------------------------------------------------------
136 // ciInstanceKlass::compute_shared_nof_implementors
137 int ciInstanceKlass::compute_shared_nof_implementors() {
138 // We requery this property, since it is a very old ciObject.
139 GUARDED_VM_ENTRY(
140 instanceKlass* ik = get_instanceKlass();
141 _nof_implementors = ik->nof_implementors();
142 return _nof_implementors;
143 )
144 }
145
146 // ------------------------------------------------------------------
147 // ciInstanceKlass::loader
148 oop ciInstanceKlass::loader() {
149 ASSERT_IN_VM;
150 return JNIHandles::resolve(_loader);
151 }
152
153 // ------------------------------------------------------------------
154 // ciInstanceKlass::loader_handle
155 jobject ciInstanceKlass::loader_handle() {
156 return _loader;
157 }
158
159 // ------------------------------------------------------------------
160 // ciInstanceKlass::protection_domain
161 oop ciInstanceKlass::protection_domain() {
162 ASSERT_IN_VM;
163 return JNIHandles::resolve(_protection_domain);
164 }
165
166 // ------------------------------------------------------------------
167 // ciInstanceKlass::protection_domain_handle
168 jobject ciInstanceKlass::protection_domain_handle() {
169 return _protection_domain;
170 }
171
172 // ------------------------------------------------------------------
173 // ciInstanceKlass::field_cache
174 //
175 // Get the field cache associated with this klass.
176 ciConstantPoolCache* ciInstanceKlass::field_cache() {
177 if (is_shared()) {
178 return NULL;
179 }
180 if (_field_cache == NULL) {
181 assert(!is_java_lang_Object(), "Object has no fields");
182 Arena* arena = CURRENT_ENV->arena();
183 _field_cache = new (arena) ciConstantPoolCache(arena, 5);
184 }
185 return _field_cache;
186 }
187
188 // ------------------------------------------------------------------
189 // ciInstanceKlass::get_canonical_holder
190 //
191 ciInstanceKlass* ciInstanceKlass::get_canonical_holder(int offset) {
192 #ifdef ASSERT
193 if (!(offset >= 0 && offset < layout_helper())) {
194 tty->print("*** get_canonical_holder(%d) on ", offset);
195 this->print();
196 tty->print_cr(" ***");
197 };
198 assert(offset >= 0 && offset < layout_helper(), "offset must be tame");
199 #endif
200
201 if (offset < instanceOopDesc::base_offset_in_bytes()) {
202 // All header offsets belong properly to java/lang/Object.
203 return CURRENT_ENV->Object_klass();
204 }
205
206 ciInstanceKlass* self = this;
207 for (;;) {
208 assert(self->is_loaded(), "must be loaded to have size");
209 ciInstanceKlass* super = self->super();
210 if (super == NULL || super->nof_nonstatic_fields() == 0 ||
211 !super->contains_field_offset(offset)) {
212 return self;
213 } else {
214 self = super; // return super->get_canonical_holder(offset)
215 }
216 }
217 }
218
219 // ------------------------------------------------------------------
220 // ciInstanceKlass::is_java_lang_Object
221 //
222 // Is this klass java.lang.Object?
223 bool ciInstanceKlass::is_java_lang_Object() {
224 return equals(CURRENT_ENV->Object_klass());
225 }
226
227 // ------------------------------------------------------------------
228 // ciInstanceKlass::uses_default_loader
229 bool ciInstanceKlass::uses_default_loader() {
230 // Note: We do not need to resolve the handle or enter the VM
231 // in order to test null-ness.
232 return _loader == NULL;
233 }
234
235 // ------------------------------------------------------------------
236 // ciInstanceKlass::is_in_package
237 //
238 // Is this klass in the given package?
239 bool ciInstanceKlass::is_in_package(const char* packagename, int len) {
240 // To avoid class loader mischief, this test always rejects application classes.
241 if (!uses_default_loader())
242 return false;
243 GUARDED_VM_ENTRY(
244 return is_in_package_impl(packagename, len);
245 )
246 }
247
248 bool ciInstanceKlass::is_in_package_impl(const char* packagename, int len) {
249 ASSERT_IN_VM;
250
251 // If packagename contains trailing '/' exclude it from the
252 // prefix-test since we test for it explicitly.
253 if (packagename[len - 1] == '/')
254 len--;
255
256 if (!name()->starts_with(packagename, len))
257 return false;
258
259 // Test if the class name is something like "java/lang".
260 if ((len + 1) > name()->utf8_length())
261 return false;
262
263 // Test for trailing '/'
264 if ((char) name()->byte_at(len) != '/')
265 return false;
266
267 // Make sure it's not actually in a subpackage:
268 if (name()->index_of_at(len+1, "/", 1) >= 0)
269 return false;
270
271 return true;
272 }
273
274 // ------------------------------------------------------------------
275 // ciInstanceKlass::print_impl
276 //
277 // Implementation of the print method.
278 void ciInstanceKlass::print_impl(outputStream* st) {
279 ciKlass::print_impl(st);
280 GUARDED_VM_ENTRY(st->print(" loader=0x%x", (address)loader());)
281 if (is_loaded()) {
282 st->print(" loaded=true initialized=%s finalized=%s subklass=%s size=%d flags=",
283 bool_to_str(is_initialized()),
284 bool_to_str(has_finalizer()),
285 bool_to_str(has_subklass()),
286 layout_helper());
287
288 _flags.print_klass_flags();
289
290 if (_super) {
291 st->print(" super=");
292 _super->print_name();
293 }
294 if (_java_mirror) {
295 st->print(" mirror=PRESENT");
296 }
297 } else {
298 st->print(" loaded=false");
299 }
300 }
301
302 // ------------------------------------------------------------------
303 // ciInstanceKlass::super
304 //
305 // Get the superklass of this klass.
306 ciInstanceKlass* ciInstanceKlass::super() {
307 assert(is_loaded(), "must be loaded");
308 if (_super == NULL && !is_java_lang_Object()) {
309 GUARDED_VM_ENTRY(
310 klassOop super_klass = get_instanceKlass()->super();
311 _super = CURRENT_ENV->get_object(super_klass)->as_instance_klass();
312 )
313 }
314 return _super;
315 }
316
317 // ------------------------------------------------------------------
318 // ciInstanceKlass::java_mirror
319 //
320 // Get the instance of java.lang.Class corresponding to this klass.
321 // Cache it on this->_java_mirror.
322 ciInstance* ciInstanceKlass::java_mirror() {
323 if (_java_mirror == NULL) {
324 _java_mirror = ciKlass::java_mirror();
325 }
326 return _java_mirror;
327 }
328
329 // ------------------------------------------------------------------
330 // ciInstanceKlass::unique_concrete_subklass
331 ciInstanceKlass* ciInstanceKlass::unique_concrete_subklass() {
332 if (!is_loaded()) return NULL; // No change if class is not loaded
333 if (!is_abstract()) return NULL; // Only applies to abstract classes.
334 if (!has_subklass()) return NULL; // Must have at least one subklass.
335 VM_ENTRY_MARK;
336 instanceKlass* ik = get_instanceKlass();
337 Klass* up = ik->up_cast_abstract();
338 assert(up->oop_is_instance(), "must be instanceKlass");
339 if (ik == up) {
340 return NULL;
341 }
342 return CURRENT_THREAD_ENV->get_object(up->as_klassOop())->as_instance_klass();
343 }
344
345 // ------------------------------------------------------------------
346 // ciInstanceKlass::has_finalizable_subclass
347 bool ciInstanceKlass::has_finalizable_subclass() {
348 if (!is_loaded()) return true;
349 VM_ENTRY_MARK;
350 return Dependencies::find_finalizable_subclass(get_instanceKlass()) != NULL;
351 }
352
353 // ------------------------------------------------------------------
354 // ciInstanceKlass::get_field_by_offset
355 ciField* ciInstanceKlass::get_field_by_offset(int field_offset, bool is_static) {
356 if (!is_static) {
357 for (int i = 0, len = nof_nonstatic_fields(); i < len; i++) {
358 ciField* field = _nonstatic_fields->at(i);
359 int field_off = field->offset_in_bytes();
360 if (field_off == field_offset)
361 return field;
362 if (field_off > field_offset)
363 break;
364 // could do binary search or check bins, but probably not worth it
365 }
366 return NULL;
367 }
368 VM_ENTRY_MARK;
369 instanceKlass* k = get_instanceKlass();
370 fieldDescriptor fd;
371 if (!k->find_field_from_offset(field_offset, is_static, &fd)) {
372 return NULL;
373 }
374 ciField* field = new (CURRENT_THREAD_ENV->arena()) ciField(&fd);
375 return field;
376 }
377
378 // ------------------------------------------------------------------
379 // ciInstanceKlass::get_field_by_name
380 ciField* ciInstanceKlass::get_field_by_name(ciSymbol* name, ciSymbol* signature, bool is_static) {
381 VM_ENTRY_MARK;
382 instanceKlass* k = get_instanceKlass();
383 fieldDescriptor fd;
384 klassOop def = k->find_field(name->get_symbol(), signature->get_symbol(), is_static, &fd);
385 if (def == NULL) {
386 return NULL;
387 }
388 ciField* field = new (CURRENT_THREAD_ENV->arena()) ciField(&fd);
389 return field;
390 }
391
392 // ------------------------------------------------------------------
393 // ciInstanceKlass::non_static_fields.
394
395 class NonStaticFieldFiller: public FieldClosure {
396 GrowableArray<ciField*>* _arr;
397 ciEnv* _curEnv;
398 public:
399 NonStaticFieldFiller(ciEnv* curEnv, GrowableArray<ciField*>* arr) :
400 _curEnv(curEnv), _arr(arr)
401 {}
402 void do_field(fieldDescriptor* fd) {
403 ciField* field = new (_curEnv->arena()) ciField(fd);
404 _arr->append(field);
405 }
406 };
407
408 GrowableArray<ciField*>* ciInstanceKlass::non_static_fields() {
409 if (_non_static_fields == NULL) {
410 VM_ENTRY_MARK;
411 ciEnv* curEnv = ciEnv::current();
412 instanceKlass* ik = get_instanceKlass();
413 int max_n_fields = ik->fields()->length()/instanceKlass::next_offset;
414
415 Arena* arena = curEnv->arena();
416 _non_static_fields =
417 new (arena) GrowableArray<ciField*>(arena, max_n_fields, 0, NULL);
418 NonStaticFieldFiller filler(curEnv, _non_static_fields);
419 ik->do_nonstatic_fields(&filler);
420 }
421 return _non_static_fields;
422 }
423
424 static int sort_field_by_offset(ciField** a, ciField** b) {
425 return (*a)->offset_in_bytes() - (*b)->offset_in_bytes();
426 // (no worries about 32-bit overflow...)
427 }
428
429 // ------------------------------------------------------------------
430 // ciInstanceKlass::compute_nonstatic_fields
431 int ciInstanceKlass::compute_nonstatic_fields() {
432 assert(is_loaded(), "must be loaded");
433
434 if (_nonstatic_fields != NULL)
435 return _nonstatic_fields->length();
436
437 if (!has_nonstatic_fields()) {
438 Arena* arena = CURRENT_ENV->arena();
439 _nonstatic_fields = new (arena) GrowableArray<ciField*>(arena, 0, 0, NULL);
440 return 0;
441 }
442 assert(!is_java_lang_Object(), "bootstrap OK");
443
444 // Size in bytes of my fields, including inherited fields.
445 int fsize = nonstatic_field_size() * heapOopSize;
446
447 ciInstanceKlass* super = this->super();
448 GrowableArray<ciField*>* super_fields = NULL;
449 if (super != NULL && super->has_nonstatic_fields()) {
450 int super_fsize = super->nonstatic_field_size() * heapOopSize;
451 int super_flen = super->nof_nonstatic_fields();
452 super_fields = super->_nonstatic_fields;
453 assert(super_flen == 0 || super_fields != NULL, "first get nof_fields");
454 // See if I am no larger than my super; if so, I can use his fields.
455 if (fsize == super_fsize) {
456 _nonstatic_fields = super_fields;
457 return super_fields->length();
458 }
459 }
460
461 GrowableArray<ciField*>* fields = NULL;
462 GUARDED_VM_ENTRY({
463 fields = compute_nonstatic_fields_impl(super_fields);
464 });
465
466 if (fields == NULL) {
467 // This can happen if this class (java.lang.Class) has invisible fields.
468 _nonstatic_fields = super_fields;
469 return super_fields->length();
470 }
471
472 int flen = fields->length();
473
474 // Now sort them by offset, ascending.
475 // (In principle, they could mix with superclass fields.)
476 fields->sort(sort_field_by_offset);
477 #ifdef ASSERT
478 int last_offset = instanceOopDesc::base_offset_in_bytes();
479 for (int i = 0; i < fields->length(); i++) {
480 ciField* field = fields->at(i);
481 int offset = field->offset_in_bytes();
482 int size = (field->_type == NULL) ? heapOopSize : field->size_in_bytes();
483 assert(last_offset <= offset, err_msg("no field overlap: %d <= %d", last_offset, offset));
484 if (last_offset > (int)sizeof(oopDesc))
485 assert((offset - last_offset) < BytesPerLong, "no big holes");
486 // Note: Two consecutive T_BYTE fields will be separated by wordSize-1
487 // padding bytes if one of them is declared by a superclass.
488 // This is a minor inefficiency classFileParser.cpp.
489 last_offset = offset + size;
490 }
491 assert(last_offset <= (int)instanceOopDesc::base_offset_in_bytes() + fsize, "no overflow");
492 #endif
493
494 _nonstatic_fields = fields;
495 return flen;
496 }
497
498 GrowableArray<ciField*>*
499 ciInstanceKlass::compute_nonstatic_fields_impl(GrowableArray<ciField*>*
500 super_fields) {
501 ASSERT_IN_VM;
502 Arena* arena = CURRENT_ENV->arena();
503 int flen = 0;
504 GrowableArray<ciField*>* fields = NULL;
505 instanceKlass* k = get_instanceKlass();
506 typeArrayOop fields_array = k->fields();
507 for (int pass = 0; pass <= 1; pass++) {
508 for (int i = 0, alen = fields_array->length(); i < alen; i += instanceKlass::next_offset) {
509 fieldDescriptor fd;
510 fd.initialize(k->as_klassOop(), i);
511 if (fd.is_static()) continue;
512 if (pass == 0) {
513 flen += 1;
514 } else {
515 ciField* field = new (arena) ciField(&fd);
516 fields->append(field);
517 }
518 }
519
520 // Between passes, allocate the array:
521 if (pass == 0) {
522 if (flen == 0) {
523 return NULL; // return nothing if none are locally declared
524 }
525 if (super_fields != NULL) {
526 flen += super_fields->length();
527 }
528 fields = new (arena) GrowableArray<ciField*>(arena, flen, 0, NULL);
529 if (super_fields != NULL) {
530 fields->appendAll(super_fields);
531 }
532 }
533 }
534 assert(fields->length() == flen, "sanity");
535 return fields;
536 }
537
538 // ------------------------------------------------------------------
539 // ciInstanceKlass::find_method
540 //
541 // Find a method in this klass.
542 ciMethod* ciInstanceKlass::find_method(ciSymbol* name, ciSymbol* signature) {
543 VM_ENTRY_MARK;
544 instanceKlass* k = get_instanceKlass();
545 Symbol* name_sym = name->get_symbol();
546 Symbol* sig_sym= signature->get_symbol();
547
548 methodOop m = k->find_method(name_sym, sig_sym);
549 if (m == NULL) return NULL;
550
551 return CURRENT_THREAD_ENV->get_object(m)->as_method();
552 }
553
554 // ------------------------------------------------------------------
555 // ciInstanceKlass::is_leaf_type
556 bool ciInstanceKlass::is_leaf_type() {
557 assert(is_loaded(), "must be loaded");
558 if (is_shared()) {
559 return is_final(); // approximately correct
560 } else {
561 return !_has_subklass && (_nof_implementors == 0);
562 }
563 }
564
565 // ------------------------------------------------------------------
566 // ciInstanceKlass::implementor
567 //
568 // Report an implementor of this interface.
569 // Returns NULL if exact information is not available.
570 // Note that there are various races here, since my copy
571 // of _nof_implementors might be out of date with respect
572 // to results returned by instanceKlass::implementor.
573 // This is OK, since any dependencies we decide to assert
574 // will be checked later under the Compile_lock.
575 ciInstanceKlass* ciInstanceKlass::implementor(int n) {
576 if (n >= implementors_limit) {
577 return NULL;
578 }
579 ciInstanceKlass* impl = _implementors[n];
580 if (impl == NULL) {
581 if (_nof_implementors > implementors_limit) {
582 return NULL;
583 }
584 // Go into the VM to fetch the implementor.
585 {
586 VM_ENTRY_MARK;
587 klassOop k = get_instanceKlass()->implementor(n);
588 if (k != NULL) {
589 impl = CURRENT_THREAD_ENV->get_object(k)->as_instance_klass();
590 }
591 }
592 // Memoize this result.
593 if (!is_shared()) {
594 _implementors[n] = (impl == NULL)? this: impl;
595 }
596 } else if (impl == this) {
597 impl = NULL; // memoized null result from a VM query
598 }
599 return impl;
600 }