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 //compute_nonstatic_fields(); // done outside of constructor
89 }
90
91 _field_cache = NULL;
92 }
93
94 // Version for unloaded classes:
95 ciInstanceKlass::ciInstanceKlass(ciSymbol* name,
96 jobject loader, jobject protection_domain)
97 : ciKlass(name, ciInstanceKlassKlass::make())
98 {
99 assert(name->byte_at(0) != '[', "not an instance klass");
100 _init_state = (instanceKlass::ClassState)0;
101 _nonstatic_field_size = -1;
102 _has_nonstatic_fields = false;
103 _nonstatic_fields = NULL;
104 _nof_implementors = -1;
105 _loader = loader;
106 _protection_domain = protection_domain;
107 _is_shared = false;
108 _super = NULL;
109 _java_mirror = NULL;
110 _field_cache = NULL;
111 }
112
113
114
115 // ------------------------------------------------------------------
116 // ciInstanceKlass::compute_shared_is_initialized
117 void ciInstanceKlass::compute_shared_init_state() {
118 GUARDED_VM_ENTRY(
119 instanceKlass* ik = get_instanceKlass();
120 _init_state = (instanceKlass::ClassState)ik->get_init_state();
121 )
122 }
123
124 // ------------------------------------------------------------------
125 // ciInstanceKlass::compute_shared_has_subklass
126 bool ciInstanceKlass::compute_shared_has_subklass() {
127 GUARDED_VM_ENTRY(
128 instanceKlass* ik = get_instanceKlass();
129 _has_subklass = ik->subklass() != NULL;
130 return _has_subklass;
131 )
132 }
133
134 // ------------------------------------------------------------------
135 // ciInstanceKlass::compute_shared_nof_implementors
136 int ciInstanceKlass::compute_shared_nof_implementors() {
137 // We requery this property, since it is a very old ciObject.
138 GUARDED_VM_ENTRY(
139 instanceKlass* ik = get_instanceKlass();
140 _nof_implementors = ik->nof_implementors();
141 return _nof_implementors;
142 )
143 }
144
145 // ------------------------------------------------------------------
146 // ciInstanceKlass::loader
147 oop ciInstanceKlass::loader() {
148 ASSERT_IN_VM;
149 return JNIHandles::resolve(_loader);
150 }
151
152 // ------------------------------------------------------------------
153 // ciInstanceKlass::loader_handle
154 jobject ciInstanceKlass::loader_handle() {
155 return _loader;
156 }
157
158 // ------------------------------------------------------------------
159 // ciInstanceKlass::protection_domain
160 oop ciInstanceKlass::protection_domain() {
161 ASSERT_IN_VM;
162 return JNIHandles::resolve(_protection_domain);
163 }
164
165 // ------------------------------------------------------------------
166 // ciInstanceKlass::protection_domain_handle
167 jobject ciInstanceKlass::protection_domain_handle() {
168 return _protection_domain;
169 }
170
171 // ------------------------------------------------------------------
172 // ciInstanceKlass::field_cache
173 //
174 // Get the field cache associated with this klass.
175 ciConstantPoolCache* ciInstanceKlass::field_cache() {
176 if (is_shared()) {
177 return NULL;
178 }
179 if (_field_cache == NULL) {
180 assert(!is_java_lang_Object(), "Object has no fields");
181 Arena* arena = CURRENT_ENV->arena();
182 _field_cache = new (arena) ciConstantPoolCache(arena, 5);
183 }
184 return _field_cache;
185 }
186
187 // ------------------------------------------------------------------
188 // ciInstanceKlass::get_canonical_holder
189 //
190 ciInstanceKlass* ciInstanceKlass::get_canonical_holder(int offset) {
191 #ifdef ASSERT
192 if (!(offset >= 0 && offset < layout_helper())) {
193 tty->print("*** get_canonical_holder(%d) on ", offset);
194 this->print();
195 tty->print_cr(" ***");
196 };
197 assert(offset >= 0 && offset < layout_helper(), "offset must be tame");
198 #endif
199
200 if (offset < instanceOopDesc::base_offset_in_bytes()) {
201 // All header offsets belong properly to java/lang/Object.
202 return CURRENT_ENV->Object_klass();
203 }
204
205 ciInstanceKlass* self = this;
206 for (;;) {
207 assert(self->is_loaded(), "must be loaded to have size");
208 ciInstanceKlass* super = self->super();
209 if (super == NULL || super->nof_nonstatic_fields() == 0 ||
210 !super->contains_field_offset(offset)) {
211 return self;
212 } else {
213 self = super; // return super->get_canonical_holder(offset)
214 }
215 }
216 }
217
218 // ------------------------------------------------------------------
219 // ciInstanceKlass::is_java_lang_Object
220 //
221 // Is this klass java.lang.Object?
222 bool ciInstanceKlass::is_java_lang_Object() {
223 return equals(CURRENT_ENV->Object_klass());
224 }
225
226 // ------------------------------------------------------------------
227 // ciInstanceKlass::uses_default_loader
228 bool ciInstanceKlass::uses_default_loader() {
229 // Note: We do not need to resolve the handle or enter the VM
230 // in order to test null-ness.
231 return _loader == NULL;
232 }
233
234 // ------------------------------------------------------------------
235 // ciInstanceKlass::is_in_package
236 //
237 // Is this klass in the given package?
238 bool ciInstanceKlass::is_in_package(const char* packagename, int len) {
239 // To avoid class loader mischief, this test always rejects application classes.
240 if (!uses_default_loader())
241 return false;
242 GUARDED_VM_ENTRY(
243 return is_in_package_impl(packagename, len);
244 )
245 }
246
247 bool ciInstanceKlass::is_in_package_impl(const char* packagename, int len) {
248 ASSERT_IN_VM;
249
250 // If packagename contains trailing '/' exclude it from the
251 // prefix-test since we test for it explicitly.
252 if (packagename[len - 1] == '/')
253 len--;
254
255 if (!name()->starts_with(packagename, len))
256 return false;
257
258 // Test if the class name is something like "java/lang".
259 if ((len + 1) > name()->utf8_length())
260 return false;
261
262 // Test for trailing '/'
263 if ((char) name()->byte_at(len) != '/')
264 return false;
265
266 // Make sure it's not actually in a subpackage:
267 if (name()->index_of_at(len+1, "/", 1) >= 0)
268 return false;
269
270 return true;
271 }
272
273 // ------------------------------------------------------------------
274 // ciInstanceKlass::print_impl
275 //
276 // Implementation of the print method.
277 void ciInstanceKlass::print_impl(outputStream* st) {
278 ciKlass::print_impl(st);
279 GUARDED_VM_ENTRY(st->print(" loader=0x%x", (address)loader());)
280 if (is_loaded()) {
281 st->print(" loaded=true initialized=%s finalized=%s subklass=%s size=%d flags=",
282 bool_to_str(is_initialized()),
283 bool_to_str(has_finalizer()),
284 bool_to_str(has_subklass()),
285 layout_helper());
286
287 _flags.print_klass_flags();
288
289 if (_super) {
290 st->print(" super=");
291 _super->print_name();
292 }
293 if (_java_mirror) {
294 st->print(" mirror=PRESENT");
295 }
296 } else {
297 st->print(" loaded=false");
298 }
299 }
300
301 // ------------------------------------------------------------------
302 // ciInstanceKlass::super
303 //
304 // Get the superklass of this klass.
305 ciInstanceKlass* ciInstanceKlass::super() {
306 assert(is_loaded(), "must be loaded");
307 if (_super == NULL && !is_java_lang_Object()) {
308 GUARDED_VM_ENTRY(
309 klassOop super_klass = get_instanceKlass()->super();
310 _super = CURRENT_ENV->get_object(super_klass)->as_instance_klass();
311 )
312 }
313 return _super;
314 }
315
316 // ------------------------------------------------------------------
317 // ciInstanceKlass::java_mirror
318 //
319 // Get the instance of java.lang.Class corresponding to this klass.
320 // Cache it on this->_java_mirror.
321 ciInstance* ciInstanceKlass::java_mirror() {
322 if (is_shared()) {
323 return ciKlass::java_mirror();
324 }
325 if (_java_mirror == NULL) {
326 _java_mirror = ciKlass::java_mirror();
327 }
328 return _java_mirror;
329 }
330
331 // ------------------------------------------------------------------
332 // ciInstanceKlass::unique_concrete_subklass
333 ciInstanceKlass* ciInstanceKlass::unique_concrete_subklass() {
334 if (!is_loaded()) return NULL; // No change if class is not loaded
335 if (!is_abstract()) return NULL; // Only applies to abstract classes.
336 if (!has_subklass()) return NULL; // Must have at least one subklass.
337 VM_ENTRY_MARK;
338 instanceKlass* ik = get_instanceKlass();
339 Klass* up = ik->up_cast_abstract();
340 assert(up->oop_is_instance(), "must be instanceKlass");
341 if (ik == up) {
342 return NULL;
343 }
344 return CURRENT_THREAD_ENV->get_object(up->as_klassOop())->as_instance_klass();
345 }
346
347 // ------------------------------------------------------------------
348 // ciInstanceKlass::has_finalizable_subclass
349 bool ciInstanceKlass::has_finalizable_subclass() {
350 if (!is_loaded()) return true;
351 VM_ENTRY_MARK;
352 return Dependencies::find_finalizable_subclass(get_instanceKlass()) != NULL;
353 }
354
355 // ------------------------------------------------------------------
356 // ciInstanceKlass::get_field_by_offset
357 ciField* ciInstanceKlass::get_field_by_offset(int field_offset, bool is_static) {
358 if (!is_static) {
359 for (int i = 0, len = nof_nonstatic_fields(); i < len; i++) {
360 ciField* field = _nonstatic_fields->at(i);
361 int field_off = field->offset_in_bytes();
362 if (field_off == field_offset)
363 return field;
364 if (field_off > field_offset)
365 break;
366 // could do binary search or check bins, but probably not worth it
367 }
368 return NULL;
369 }
370 VM_ENTRY_MARK;
371 instanceKlass* k = get_instanceKlass();
372 fieldDescriptor fd;
373 if (!k->find_field_from_offset(field_offset, is_static, &fd)) {
374 return NULL;
375 }
376 ciField* field = new (CURRENT_THREAD_ENV->arena()) ciField(&fd);
377 return field;
378 }
379
380 // ------------------------------------------------------------------
381 // ciInstanceKlass::get_field_by_name
382 ciField* ciInstanceKlass::get_field_by_name(ciSymbol* name, ciSymbol* signature, bool is_static) {
383 VM_ENTRY_MARK;
384 instanceKlass* k = get_instanceKlass();
385 fieldDescriptor fd;
386 klassOop def = k->find_field(name->get_symbol(), signature->get_symbol(), is_static, &fd);
387 if (def == NULL) {
388 return NULL;
389 }
390 ciField* field = new (CURRENT_THREAD_ENV->arena()) ciField(&fd);
391 return field;
392 }
393
394 // ------------------------------------------------------------------
395 // ciInstanceKlass::non_static_fields.
396
397 class NonStaticFieldFiller: public FieldClosure {
398 GrowableArray<ciField*>* _arr;
399 ciEnv* _curEnv;
400 public:
401 NonStaticFieldFiller(ciEnv* curEnv, GrowableArray<ciField*>* arr) :
402 _curEnv(curEnv), _arr(arr)
403 {}
404 void do_field(fieldDescriptor* fd) {
405 ciField* field = new (_curEnv->arena()) ciField(fd);
406 _arr->append(field);
407 }
408 };
409
410 GrowableArray<ciField*>* ciInstanceKlass::non_static_fields() {
411 if (_non_static_fields == NULL) {
412 VM_ENTRY_MARK;
413 ciEnv* curEnv = ciEnv::current();
414 instanceKlass* ik = get_instanceKlass();
415 int max_n_fields = ik->fields()->length()/instanceKlass::next_offset;
416
417 Arena* arena = curEnv->arena();
418 _non_static_fields =
419 new (arena) GrowableArray<ciField*>(arena, max_n_fields, 0, NULL);
420 NonStaticFieldFiller filler(curEnv, _non_static_fields);
421 ik->do_nonstatic_fields(&filler);
422 }
423 return _non_static_fields;
424 }
425
426 static int sort_field_by_offset(ciField** a, ciField** b) {
427 return (*a)->offset_in_bytes() - (*b)->offset_in_bytes();
428 // (no worries about 32-bit overflow...)
429 }
430
431 // ------------------------------------------------------------------
432 // ciInstanceKlass::compute_nonstatic_fields
433 int ciInstanceKlass::compute_nonstatic_fields() {
434 assert(is_loaded(), "must be loaded");
435
436 if (_nonstatic_fields != NULL)
437 return _nonstatic_fields->length();
438
439 if (!has_nonstatic_fields()) {
440 Arena* arena = CURRENT_ENV->arena();
441 _nonstatic_fields = new (arena) GrowableArray<ciField*>(arena, 0, 0, NULL);
442 return 0;
443 }
444 assert(!is_java_lang_Object(), "bootstrap OK");
445
446 // Size in bytes of my fields, including inherited fields.
447 int fsize = nonstatic_field_size() * heapOopSize;
448
449 ciInstanceKlass* super = this->super();
450 GrowableArray<ciField*>* super_fields = NULL;
451 if (super != NULL && super->has_nonstatic_fields()) {
452 int super_fsize = super->nonstatic_field_size() * heapOopSize;
453 int super_flen = super->nof_nonstatic_fields();
454 super_fields = super->_nonstatic_fields;
455 assert(super_flen == 0 || super_fields != NULL, "first get nof_fields");
456 // See if I am no larger than my super; if so, I can use his fields.
457 if (fsize == super_fsize) {
458 _nonstatic_fields = super_fields;
459 return super_fields->length();
460 }
461 }
462
463 GrowableArray<ciField*>* fields = NULL;
464 GUARDED_VM_ENTRY({
465 fields = compute_nonstatic_fields_impl(super_fields);
466 });
467
468 if (fields == NULL) {
469 // This can happen if this class (java.lang.Class) has invisible fields.
470 _nonstatic_fields = super_fields;
471 return super_fields->length();
472 }
473
474 int flen = fields->length();
475
476 // Now sort them by offset, ascending.
477 // (In principle, they could mix with superclass fields.)
478 fields->sort(sort_field_by_offset);
479 #ifdef ASSERT
480 int last_offset = instanceOopDesc::base_offset_in_bytes();
481 for (int i = 0; i < fields->length(); i++) {
482 ciField* field = fields->at(i);
483 int offset = field->offset_in_bytes();
484 int size = (field->_type == NULL) ? heapOopSize : field->size_in_bytes();
485 assert(last_offset <= offset, err_msg("no field overlap: %d <= %d", last_offset, offset));
486 if (last_offset > (int)sizeof(oopDesc))
487 assert((offset - last_offset) < BytesPerLong, "no big holes");
488 // Note: Two consecutive T_BYTE fields will be separated by wordSize-1
489 // padding bytes if one of them is declared by a superclass.
490 // This is a minor inefficiency classFileParser.cpp.
491 last_offset = offset + size;
492 }
493 assert(last_offset <= (int)instanceOopDesc::base_offset_in_bytes() + fsize, "no overflow");
494 #endif
495
496 _nonstatic_fields = fields;
497 return flen;
498 }
499
500 GrowableArray<ciField*>*
501 ciInstanceKlass::compute_nonstatic_fields_impl(GrowableArray<ciField*>*
502 super_fields) {
503 ASSERT_IN_VM;
504 Arena* arena = CURRENT_ENV->arena();
505 int flen = 0;
506 GrowableArray<ciField*>* fields = NULL;
507 instanceKlass* k = get_instanceKlass();
508 typeArrayOop fields_array = k->fields();
509 for (int pass = 0; pass <= 1; pass++) {
510 for (int i = 0, alen = fields_array->length(); i < alen; i += instanceKlass::next_offset) {
511 fieldDescriptor fd;
512 fd.initialize(k->as_klassOop(), i);
513 if (fd.is_static()) continue;
514 if (pass == 0) {
515 flen += 1;
516 } else {
517 ciField* field = new (arena) ciField(&fd);
518 fields->append(field);
519 }
520 }
521
522 // Between passes, allocate the array:
523 if (pass == 0) {
524 if (flen == 0) {
525 return NULL; // return nothing if none are locally declared
526 }
527 if (super_fields != NULL) {
528 flen += super_fields->length();
529 }
530 fields = new (arena) GrowableArray<ciField*>(arena, flen, 0, NULL);
531 if (super_fields != NULL) {
532 fields->appendAll(super_fields);
533 }
534 }
535 }
536 assert(fields->length() == flen, "sanity");
537 return fields;
538 }
539
540 // ------------------------------------------------------------------
541 // ciInstanceKlass::find_method
542 //
543 // Find a method in this klass.
544 ciMethod* ciInstanceKlass::find_method(ciSymbol* name, ciSymbol* signature) {
545 VM_ENTRY_MARK;
546 instanceKlass* k = get_instanceKlass();
547 Symbol* name_sym = name->get_symbol();
548 Symbol* sig_sym= signature->get_symbol();
549
550 methodOop m = k->find_method(name_sym, sig_sym);
551 if (m == NULL) return NULL;
552
553 return CURRENT_THREAD_ENV->get_object(m)->as_method();
554 }
555
556 // ------------------------------------------------------------------
557 // ciInstanceKlass::is_leaf_type
558 bool ciInstanceKlass::is_leaf_type() {
559 assert(is_loaded(), "must be loaded");
560 if (is_shared()) {
561 return is_final(); // approximately correct
562 } else {
563 return !_has_subklass && (_nof_implementors == 0);
564 }
565 }
566
567 // ------------------------------------------------------------------
568 // ciInstanceKlass::implementor
569 //
570 // Report an implementor of this interface.
571 // Returns NULL if exact information is not available.
572 // Note that there are various races here, since my copy
573 // of _nof_implementors might be out of date with respect
574 // to results returned by instanceKlass::implementor.
575 // This is OK, since any dependencies we decide to assert
576 // will be checked later under the Compile_lock.
577 ciInstanceKlass* ciInstanceKlass::implementor(int n) {
578 if (n >= implementors_limit) {
579 return NULL;
580 }
581 ciInstanceKlass* impl = _implementors[n];
582 if (impl == NULL) {
583 if (_nof_implementors > implementors_limit) {
584 return NULL;
585 }
586 // Go into the VM to fetch the implementor.
587 {
588 VM_ENTRY_MARK;
589 klassOop k = get_instanceKlass()->implementor(n);
590 if (k != NULL) {
591 impl = CURRENT_THREAD_ENV->get_object(k)->as_instance_klass();
592 }
593 }
594 // Memoize this result.
595 if (!is_shared()) {
596 _implementors[n] = (impl == NULL)? this: impl;
597 }
598 } else if (impl == this) {
599 impl = NULL; // memoized null result from a VM query
600 }
601 return impl;
602 }