1 /*
2 * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "classfile/classLoaderDataGraph.hpp"
27 #include "classfile/metadataOnStackMark.hpp"
28 #include "classfile/systemDictionary.hpp"
29 #include "code/codeCache.hpp"
30 #include "code/debugInfoRec.hpp"
31 #include "gc/shared/collectedHeap.inline.hpp"
32 #include "interpreter/bytecodeStream.hpp"
33 #include "interpreter/bytecodeTracer.hpp"
34 #include "interpreter/bytecodes.hpp"
35 #include "interpreter/interpreter.hpp"
36 #include "interpreter/oopMapCache.hpp"
37 #include "memory/allocation.inline.hpp"
38 #include "memory/heapInspection.hpp"
39 #include "memory/metadataFactory.hpp"
40 #include "memory/metaspaceClosure.hpp"
41 #include "memory/metaspaceShared.hpp"
42 #include "memory/oopFactory.hpp"
43 #include "memory/resourceArea.hpp"
44 #include "oops/constMethod.hpp"
45 #include "oops/constantPool.hpp"
46 #include "oops/method.inline.hpp"
47 #include "oops/methodData.hpp"
48 #include "oops/objArrayOop.inline.hpp"
49 #include "oops/oop.inline.hpp"
50 #include "oops/symbol.hpp"
51 #include "oops/valueKlass.hpp"
52 #include "prims/jvmtiExport.hpp"
53 #include "prims/methodHandles.hpp"
54 #include "prims/nativeLookup.hpp"
55 #include "runtime/arguments.hpp"
56 #include "runtime/compilationPolicy.hpp"
57 #include "runtime/frame.inline.hpp"
58 #include "runtime/handles.inline.hpp"
59 #include "runtime/init.hpp"
60 #include "runtime/orderAccess.hpp"
61 #include "runtime/relocator.hpp"
62 #include "runtime/safepointVerifiers.hpp"
63 #include "runtime/sharedRuntime.hpp"
64 #include "runtime/signature.hpp"
65 #include "utilities/align.hpp"
66 #include "utilities/quickSort.hpp"
67 #include "utilities/vmError.hpp"
68 #include "utilities/xmlstream.hpp"
69
70 // Implementation of Method
71
72 Method* Method::allocate(ClassLoaderData* loader_data,
73 int byte_code_size,
74 AccessFlags access_flags,
75 InlineTableSizes* sizes,
76 ConstMethod::MethodType method_type,
77 TRAPS) {
78 assert(!access_flags.is_native() || byte_code_size == 0,
79 "native methods should not contain byte codes");
80 ConstMethod* cm = ConstMethod::allocate(loader_data,
81 byte_code_size,
82 sizes,
83 method_type,
84 CHECK_NULL);
85 int size = Method::size(access_flags.is_native());
86 return new (loader_data, size, MetaspaceObj::MethodType, THREAD) Method(cm, access_flags);
87 }
88
89 Method::Method(ConstMethod* xconst, AccessFlags access_flags) {
90 NoSafepointVerifier no_safepoint;
91 set_constMethod(xconst);
92 set_access_flags(access_flags);
93 set_intrinsic_id(vmIntrinsics::_none);
94 set_force_inline(false);
95 set_hidden(false);
96 set_dont_inline(false);
97 set_has_injected_profile(false);
98 set_method_data(NULL);
99 clear_method_counters();
100 set_vtable_index(Method::garbage_vtable_index);
101
102 // Fix and bury in Method*
103 set_interpreter_entry(NULL); // sets i2i entry and from_int
104 set_adapter_entry(NULL);
105 clear_code(false /* don't need a lock */); // from_c/from_i get set to c2i/i2i
106
107 if (access_flags.is_native()) {
108 clear_native_function();
109 set_signature_handler(NULL);
110 }
111 NOT_PRODUCT(set_compiled_invocation_count(0);)
112 }
113
114 // Release Method*. The nmethod will be gone when we get here because
115 // we've walked the code cache.
116 void Method::deallocate_contents(ClassLoaderData* loader_data) {
117 MetadataFactory::free_metadata(loader_data, constMethod());
118 set_constMethod(NULL);
119 MetadataFactory::free_metadata(loader_data, method_data());
120 set_method_data(NULL);
121 MetadataFactory::free_metadata(loader_data, method_counters());
122 clear_method_counters();
123 // The nmethod will be gone when we get here.
124 if (code() != NULL) _code = NULL;
125 }
126
127 address Method::get_i2c_entry() {
128 assert(adapter() != NULL, "must have");
129 return adapter()->get_i2c_entry();
130 }
131
132 address Method::get_c2i_entry() {
133 assert(adapter() != NULL, "must have");
134 return adapter()->get_c2i_entry();
135 }
136
137 address Method::get_c2i_value_entry() {
138 assert(adapter() != NULL, "must have");
139 return adapter()->get_c2i_value_entry();
140 }
141
142 address Method::get_c2i_unverified_entry() {
143 assert(adapter() != NULL, "must have");
144 return adapter()->get_c2i_unverified_entry();
145 }
146
147 char* Method::name_and_sig_as_C_string() const {
148 return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature());
149 }
150
151 char* Method::name_and_sig_as_C_string(char* buf, int size) const {
152 return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature(), buf, size);
153 }
154
155 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature) {
156 const char* klass_name = klass->external_name();
157 int klass_name_len = (int)strlen(klass_name);
158 int method_name_len = method_name->utf8_length();
159 int len = klass_name_len + 1 + method_name_len + signature->utf8_length();
160 char* dest = NEW_RESOURCE_ARRAY(char, len + 1);
161 strcpy(dest, klass_name);
162 dest[klass_name_len] = '.';
163 strcpy(&dest[klass_name_len + 1], method_name->as_C_string());
164 strcpy(&dest[klass_name_len + 1 + method_name_len], signature->as_C_string());
165 dest[len] = 0;
166 return dest;
167 }
168
169 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size) {
170 Symbol* klass_name = klass->name();
171 klass_name->as_klass_external_name(buf, size);
172 int len = (int)strlen(buf);
173
174 if (len < size - 1) {
175 buf[len++] = '.';
176
177 method_name->as_C_string(&(buf[len]), size - len);
178 len = (int)strlen(buf);
179
180 signature->as_C_string(&(buf[len]), size - len);
181 }
182
183 return buf;
184 }
185
186 int Method::fast_exception_handler_bci_for(const methodHandle& mh, Klass* ex_klass, int throw_bci, TRAPS) {
187 // exception table holds quadruple entries of the form (beg_bci, end_bci, handler_bci, klass_index)
188 // access exception table
189 ExceptionTable table(mh());
190 int length = table.length();
191 // iterate through all entries sequentially
192 constantPoolHandle pool(THREAD, mh->constants());
193 for (int i = 0; i < length; i ++) {
194 //reacquire the table in case a GC happened
195 ExceptionTable table(mh());
196 int beg_bci = table.start_pc(i);
197 int end_bci = table.end_pc(i);
198 assert(beg_bci <= end_bci, "inconsistent exception table");
199 if (beg_bci <= throw_bci && throw_bci < end_bci) {
200 // exception handler bci range covers throw_bci => investigate further
201 int handler_bci = table.handler_pc(i);
202 int klass_index = table.catch_type_index(i);
203 if (klass_index == 0) {
204 return handler_bci;
205 } else if (ex_klass == NULL) {
206 return handler_bci;
207 } else {
208 // we know the exception class => get the constraint class
209 // this may require loading of the constraint class; if verification
210 // fails or some other exception occurs, return handler_bci
211 Klass* k = pool->klass_at(klass_index, CHECK_(handler_bci));
212 assert(k != NULL, "klass not loaded");
213 if (ex_klass->is_subtype_of(k)) {
214 return handler_bci;
215 }
216 }
217 }
218 }
219
220 return -1;
221 }
222
223 void Method::mask_for(int bci, InterpreterOopMap* mask) {
224 methodHandle h_this(Thread::current(), this);
225 // Only GC uses the OopMapCache during thread stack root scanning
226 // any other uses generate an oopmap but do not save it in the cache.
227 if (Universe::heap()->is_gc_active()) {
228 method_holder()->mask_for(h_this, bci, mask);
229 } else {
230 OopMapCache::compute_one_oop_map(h_this, bci, mask);
231 }
232 return;
233 }
234
235
236 int Method::bci_from(address bcp) const {
237 if (is_native() && bcp == 0) {
238 return 0;
239 }
240 #ifdef ASSERT
241 {
242 ResourceMark rm;
243 assert(is_native() && bcp == code_base() || contains(bcp) || VMError::is_error_reported(),
244 "bcp doesn't belong to this method: bcp: " INTPTR_FORMAT ", method: %s",
245 p2i(bcp), name_and_sig_as_C_string());
246 }
247 #endif
248 return bcp - code_base();
249 }
250
251
252 int Method::validate_bci(int bci) const {
253 return (bci == 0 || bci < code_size()) ? bci : -1;
254 }
255
256 // Return bci if it appears to be a valid bcp
257 // Return -1 otherwise.
258 // Used by profiling code, when invalid data is a possibility.
259 // The caller is responsible for validating the Method* itself.
260 int Method::validate_bci_from_bcp(address bcp) const {
261 // keep bci as -1 if not a valid bci
262 int bci = -1;
263 if (bcp == 0 || bcp == code_base()) {
264 // code_size() may return 0 and we allow 0 here
265 // the method may be native
266 bci = 0;
267 } else if (contains(bcp)) {
268 bci = bcp - code_base();
269 }
270 // Assert that if we have dodged any asserts, bci is negative.
271 assert(bci == -1 || bci == bci_from(bcp_from(bci)), "sane bci if >=0");
272 return bci;
273 }
274
275 address Method::bcp_from(int bci) const {
276 assert((is_native() && bci == 0) || (!is_native() && 0 <= bci && bci < code_size()),
277 "illegal bci: %d for %s method", bci, is_native() ? "native" : "non-native");
278 address bcp = code_base() + bci;
279 assert(is_native() && bcp == code_base() || contains(bcp), "bcp doesn't belong to this method");
280 return bcp;
281 }
282
283 address Method::bcp_from(address bcp) const {
284 if (is_native() && bcp == NULL) {
285 return code_base();
286 } else {
287 return bcp;
288 }
289 }
290
291 int Method::size(bool is_native) {
292 // If native, then include pointers for native_function and signature_handler
293 int extra_bytes = (is_native) ? 2*sizeof(address*) : 0;
294 int extra_words = align_up(extra_bytes, BytesPerWord) / BytesPerWord;
295 return align_metadata_size(header_size() + extra_words);
296 }
297
298
299 Symbol* Method::klass_name() const {
300 return method_holder()->name();
301 }
302
303
304 void Method::metaspace_pointers_do(MetaspaceClosure* it) {
305 log_trace(cds)("Iter(Method): %p", this);
306
307 it->push(&_constMethod);
308 it->push(&_method_data);
309 it->push(&_method_counters);
310 }
311
312 // Attempt to return method oop to original state. Clear any pointers
313 // (to objects outside the shared spaces). We won't be able to predict
314 // where they should point in a new JVM. Further initialize some
315 // entries now in order allow them to be write protected later.
316
317 void Method::remove_unshareable_info() {
318 unlink_method();
319 }
320
321 void Method::set_vtable_index(int index) {
322 if (is_shared() && !MetaspaceShared::remapped_readwrite()) {
323 // At runtime initialize_vtable is rerun as part of link_class_impl()
324 // for a shared class loaded by the non-boot loader to obtain the loader
325 // constraints based on the runtime classloaders' context.
326 return; // don't write into the shared class
327 } else {
328 _vtable_index = index;
329 }
330 }
331
332 void Method::set_itable_index(int index) {
333 if (is_shared() && !MetaspaceShared::remapped_readwrite()) {
334 // At runtime initialize_itable is rerun as part of link_class_impl()
335 // for a shared class loaded by the non-boot loader to obtain the loader
336 // constraints based on the runtime classloaders' context. The dumptime
337 // itable index should be the same as the runtime index.
338 assert(_vtable_index == itable_index_max - index,
339 "archived itable index is different from runtime index");
340 return; // don’t write into the shared class
341 } else {
342 _vtable_index = itable_index_max - index;
343 }
344 assert(valid_itable_index(), "");
345 }
346
347
348
349 bool Method::was_executed_more_than(int n) {
350 // Invocation counter is reset when the Method* is compiled.
351 // If the method has compiled code we therefore assume it has
352 // be excuted more than n times.
353 if (is_accessor() || is_empty_method() || (code() != NULL)) {
354 // interpreter doesn't bump invocation counter of trivial methods
355 // compiler does not bump invocation counter of compiled methods
356 return true;
357 }
358 else if ((method_counters() != NULL &&
359 method_counters()->invocation_counter()->carry()) ||
360 (method_data() != NULL &&
361 method_data()->invocation_counter()->carry())) {
362 // The carry bit is set when the counter overflows and causes
363 // a compilation to occur. We don't know how many times
364 // the counter has been reset, so we simply assume it has
365 // been executed more than n times.
366 return true;
367 } else {
368 return invocation_count() > n;
369 }
370 }
371
372 void Method::print_invocation_count() {
373 if (is_static()) tty->print("static ");
374 if (is_final()) tty->print("final ");
375 if (is_synchronized()) tty->print("synchronized ");
376 if (is_native()) tty->print("native ");
377 tty->print("%s::", method_holder()->external_name());
378 name()->print_symbol_on(tty);
379 signature()->print_symbol_on(tty);
380
381 if (WizardMode) {
382 // dump the size of the byte codes
383 tty->print(" {%d}", code_size());
384 }
385 tty->cr();
386
387 tty->print_cr (" interpreter_invocation_count: %8d ", interpreter_invocation_count());
388 tty->print_cr (" invocation_counter: %8d ", invocation_count());
389 tty->print_cr (" backedge_counter: %8d ", backedge_count());
390 #ifndef PRODUCT
391 if (CountCompiledCalls) {
392 tty->print_cr (" compiled_invocation_count: %8d ", compiled_invocation_count());
393 }
394 #endif
395 }
396
397 // Build a MethodData* object to hold information about this method
398 // collected in the interpreter.
399 void Method::build_interpreter_method_data(const methodHandle& method, TRAPS) {
400 // Do not profile the method if metaspace has hit an OOM previously
401 // allocating profiling data. Callers clear pending exception so don't
402 // add one here.
403 if (ClassLoaderDataGraph::has_metaspace_oom()) {
404 return;
405 }
406
407 // Grab a lock here to prevent multiple
408 // MethodData*s from being created.
409 MutexLocker ml(MethodData_lock, THREAD);
410 if (method->method_data() == NULL) {
411 ClassLoaderData* loader_data = method->method_holder()->class_loader_data();
412 MethodData* method_data = MethodData::allocate(loader_data, method, THREAD);
413 if (HAS_PENDING_EXCEPTION) {
414 CompileBroker::log_metaspace_failure();
415 ClassLoaderDataGraph::set_metaspace_oom(true);
416 return; // return the exception (which is cleared)
417 }
418
419 method->set_method_data(method_data);
420 if (PrintMethodData && (Verbose || WizardMode)) {
421 ResourceMark rm(THREAD);
422 tty->print("build_interpreter_method_data for ");
423 method->print_name(tty);
424 tty->cr();
425 // At the end of the run, the MDO, full of data, will be dumped.
426 }
427 }
428 }
429
430 MethodCounters* Method::build_method_counters(Method* m, TRAPS) {
431 // Do not profile the method if metaspace has hit an OOM previously
432 if (ClassLoaderDataGraph::has_metaspace_oom()) {
433 return NULL;
434 }
435
436 methodHandle mh(m);
437 MethodCounters* counters = MethodCounters::allocate(mh, THREAD);
438 if (HAS_PENDING_EXCEPTION) {
439 CompileBroker::log_metaspace_failure();
440 ClassLoaderDataGraph::set_metaspace_oom(true);
441 return NULL; // return the exception (which is cleared)
442 }
443 if (!mh->init_method_counters(counters)) {
444 MetadataFactory::free_metadata(mh->method_holder()->class_loader_data(), counters);
445 }
446
447 if (LogTouchedMethods) {
448 mh->log_touched(CHECK_NULL);
449 }
450
451 return mh->method_counters();
452 }
453
454 bool Method::init_method_counters(MethodCounters* counters) {
455 // Try to install a pointer to MethodCounters, return true on success.
456 return Atomic::replace_if_null(counters, &_method_counters);
457 }
458
459 int Method::extra_stack_words() {
460 // not an inline function, to avoid a header dependency on Interpreter
461 return extra_stack_entries() * Interpreter::stackElementSize;
462 }
463
464
465 void Method::compute_size_of_parameters(Thread *thread) {
466 ArgumentSizeComputer asc(signature());
467 set_size_of_parameters(asc.size() + (is_static() ? 0 : 1));
468 }
469
470 BasicType Method::result_type() const {
471 ResultTypeFinder rtf(signature());
472 return rtf.type();
473 }
474
475 #ifdef ASSERT
476 // ValueKlass the method is declared to return. This must not
477 // safepoint as it is called with references live on the stack at
478 // locations the GC is unaware of.
479 ValueKlass* Method::returned_value_type(Thread* thread) const {
480 SignatureStream ss(signature());
481 while (!ss.at_return_type()) {
482 ss.next();
483 }
484 Handle class_loader(thread, method_holder()->class_loader());
485 Handle protection_domain(thread, method_holder()->protection_domain());
486 Klass* k = NULL;
487 {
488 NoSafepointVerifier nsv;
489 k = ss.as_klass(class_loader, protection_domain, SignatureStream::ReturnNull, thread);
490 }
491 assert(k != NULL && !thread->has_pending_exception(), "can't resolve klass");
492 return ValueKlass::cast(k);
493 }
494 #endif
495
496 bool Method::is_empty_method() const {
497 return code_size() == 1
498 && *code_base() == Bytecodes::_return;
499 }
500
501
502 bool Method::is_vanilla_constructor() const {
503 // Returns true if this method is a vanilla constructor, i.e. an "<init>" "()V" method
504 // which only calls the superclass vanilla constructor and possibly does stores of
505 // zero constants to local fields:
506 //
507 // aload_0
508 // invokespecial
509 // indexbyte1
510 // indexbyte2
511 //
512 // followed by an (optional) sequence of:
513 //
514 // aload_0
515 // aconst_null / iconst_0 / fconst_0 / dconst_0
516 // putfield
517 // indexbyte1
518 // indexbyte2
519 //
520 // followed by:
521 //
522 // return
523
524 assert(name() == vmSymbols::object_initializer_name(), "Should only be called for default constructors");
525 assert(signature() == vmSymbols::void_method_signature(), "Should only be called for default constructors");
526 int size = code_size();
527 // Check if size match
528 if (size == 0 || size % 5 != 0) return false;
529 address cb = code_base();
530 int last = size - 1;
531 if (cb[0] != Bytecodes::_aload_0 || cb[1] != Bytecodes::_invokespecial || cb[last] != Bytecodes::_return) {
532 // Does not call superclass default constructor
533 return false;
534 }
535 // Check optional sequence
536 for (int i = 4; i < last; i += 5) {
537 if (cb[i] != Bytecodes::_aload_0) return false;
538 if (!Bytecodes::is_zero_const(Bytecodes::cast(cb[i+1]))) return false;
539 if (cb[i+2] != Bytecodes::_putfield) return false;
540 }
541 return true;
542 }
543
544
545 bool Method::compute_has_loops_flag() {
546 BytecodeStream bcs(this);
547 Bytecodes::Code bc;
548
549 while ((bc = bcs.next()) >= 0) {
550 switch( bc ) {
551 case Bytecodes::_ifeq:
552 case Bytecodes::_ifnull:
553 case Bytecodes::_iflt:
554 case Bytecodes::_ifle:
555 case Bytecodes::_ifne:
556 case Bytecodes::_ifnonnull:
557 case Bytecodes::_ifgt:
558 case Bytecodes::_ifge:
559 case Bytecodes::_if_icmpeq:
560 case Bytecodes::_if_icmpne:
561 case Bytecodes::_if_icmplt:
562 case Bytecodes::_if_icmpgt:
563 case Bytecodes::_if_icmple:
564 case Bytecodes::_if_icmpge:
565 case Bytecodes::_if_acmpeq:
566 case Bytecodes::_if_acmpne:
567 case Bytecodes::_goto:
568 case Bytecodes::_jsr:
569 if( bcs.dest() < bcs.next_bci() ) _access_flags.set_has_loops();
570 break;
571
572 case Bytecodes::_goto_w:
573 case Bytecodes::_jsr_w:
574 if( bcs.dest_w() < bcs.next_bci() ) _access_flags.set_has_loops();
575 break;
576
577 default:
578 break;
579 }
580 }
581 _access_flags.set_loops_flag_init();
582 return _access_flags.has_loops();
583 }
584
585 bool Method::is_final_method(AccessFlags class_access_flags) const {
586 // or "does_not_require_vtable_entry"
587 // default method or overpass can occur, is not final (reuses vtable entry)
588 // private methods in classes get vtable entries for backward class compatibility.
589 if (is_overpass() || is_default_method()) return false;
590 return is_final() || class_access_flags.is_final();
591 }
592
593 bool Method::is_final_method() const {
594 return is_final_method(method_holder()->access_flags());
595 }
596
597 bool Method::is_default_method() const {
598 if (method_holder() != NULL &&
599 method_holder()->is_interface() &&
600 !is_abstract() && !is_private()) {
601 return true;
602 } else {
603 return false;
604 }
605 }
606
607 bool Method::can_be_statically_bound(AccessFlags class_access_flags) const {
608 if (is_final_method(class_access_flags)) return true;
609 #ifdef ASSERT
610 ResourceMark rm;
611 bool is_nonv = (vtable_index() == nonvirtual_vtable_index);
612 if (class_access_flags.is_interface()) {
613 assert(is_nonv == is_static() || is_nonv == is_private(),
614 "nonvirtual unexpected for non-static, non-private: %s",
615 name_and_sig_as_C_string());
616 }
617 #endif
618 assert(valid_vtable_index() || valid_itable_index(), "method must be linked before we ask this question");
619 return vtable_index() == nonvirtual_vtable_index;
620 }
621
622 bool Method::can_be_statically_bound() const {
623 return can_be_statically_bound(method_holder()->access_flags());
624 }
625
626 bool Method::is_accessor() const {
627 return is_getter() || is_setter();
628 }
629
630 bool Method::is_getter() const {
631 if (code_size() != 5) return false;
632 if (size_of_parameters() != 1) return false;
633 if (java_code_at(0) != Bytecodes::_aload_0) return false;
634 if (java_code_at(1) != Bytecodes::_getfield) return false;
635 switch (java_code_at(4)) {
636 case Bytecodes::_ireturn:
637 case Bytecodes::_lreturn:
638 case Bytecodes::_freturn:
639 case Bytecodes::_dreturn:
640 case Bytecodes::_areturn:
641 break;
642 default:
643 return false;
644 }
645 return true;
646 }
647
648 bool Method::is_setter() const {
649 if (code_size() != 6) return false;
650 if (java_code_at(0) != Bytecodes::_aload_0) return false;
651 switch (java_code_at(1)) {
652 case Bytecodes::_iload_1:
653 case Bytecodes::_aload_1:
654 case Bytecodes::_fload_1:
655 if (size_of_parameters() != 2) return false;
656 break;
657 case Bytecodes::_dload_1:
658 case Bytecodes::_lload_1:
659 if (size_of_parameters() != 3) return false;
660 break;
661 default:
662 return false;
663 }
664 if (java_code_at(2) != Bytecodes::_putfield) return false;
665 if (java_code_at(5) != Bytecodes::_return) return false;
666 return true;
667 }
668
669 bool Method::is_constant_getter() const {
670 int last_index = code_size() - 1;
671 // Check if the first 1-3 bytecodes are a constant push
672 // and the last bytecode is a return.
673 return (2 <= code_size() && code_size() <= 4 &&
674 Bytecodes::is_const(java_code_at(0)) &&
675 Bytecodes::length_for(java_code_at(0)) == last_index &&
676 Bytecodes::is_return(java_code_at(last_index)));
677 }
678
679 bool Method::is_initializer() const {
680 return is_object_initializer() || is_static_initializer();
681 }
682
683 bool Method::has_valid_initializer_flags() const {
684 return (is_static() ||
685 method_holder()->major_version() < 51);
686 }
687
688 bool Method::is_static_initializer() const {
689 // For classfiles version 51 or greater, ensure that the clinit method is
690 // static. Non-static methods with the name "<clinit>" are not static
691 // initializers. (older classfiles exempted for backward compatibility)
692 return name() == vmSymbols::class_initializer_name() &&
693 has_valid_initializer_flags();
694 }
695
696 bool Method::is_object_initializer() const {
697 return name() == vmSymbols::object_initializer_name();
698 }
699
700 objArrayHandle Method::resolved_checked_exceptions_impl(Method* method, TRAPS) {
701 int length = method->checked_exceptions_length();
702 if (length == 0) { // common case
703 return objArrayHandle(THREAD, Universe::the_empty_class_klass_array());
704 } else {
705 methodHandle h_this(THREAD, method);
706 objArrayOop m_oop = oopFactory::new_objArray(SystemDictionary::Class_klass(), length, CHECK_(objArrayHandle()));
707 objArrayHandle mirrors (THREAD, m_oop);
708 for (int i = 0; i < length; i++) {
709 CheckedExceptionElement* table = h_this->checked_exceptions_start(); // recompute on each iteration, not gc safe
710 Klass* k = h_this->constants()->klass_at(table[i].class_cp_index, CHECK_(objArrayHandle()));
711 assert(k->is_subclass_of(SystemDictionary::Throwable_klass()), "invalid exception class");
712 mirrors->obj_at_put(i, k->java_mirror());
713 }
714 return mirrors;
715 }
716 };
717
718
719 int Method::line_number_from_bci(int bci) const {
720 int best_bci = 0;
721 int best_line = -1;
722 if (bci == SynchronizationEntryBCI) bci = 0;
723 if (0 <= bci && bci < code_size() && has_linenumber_table()) {
724 // The line numbers are a short array of 2-tuples [start_pc, line_number].
725 // Not necessarily sorted and not necessarily one-to-one.
726 CompressedLineNumberReadStream stream(compressed_linenumber_table());
727 while (stream.read_pair()) {
728 if (stream.bci() == bci) {
729 // perfect match
730 return stream.line();
731 } else {
732 // update best_bci/line
733 if (stream.bci() < bci && stream.bci() >= best_bci) {
734 best_bci = stream.bci();
735 best_line = stream.line();
736 }
737 }
738 }
739 }
740 return best_line;
741 }
742
743
744 bool Method::is_klass_loaded_by_klass_index(int klass_index) const {
745 if( constants()->tag_at(klass_index).is_unresolved_klass()) {
746 Thread *thread = Thread::current();
747 Symbol* klass_name = constants()->klass_name_at(klass_index);
748 Handle loader(thread, method_holder()->class_loader());
749 Handle prot (thread, method_holder()->protection_domain());
750 return SystemDictionary::find(klass_name, loader, prot, thread) != NULL;
751 } else {
752 return true;
753 }
754 }
755
756
757 bool Method::is_klass_loaded(int refinfo_index, bool must_be_resolved) const {
758 int klass_index = constants()->klass_ref_index_at(refinfo_index);
759 if (must_be_resolved) {
760 // Make sure klass is resolved in constantpool.
761 if (constants()->tag_at(klass_index).is_unresolved_klass()) {
762 return false;
763 }
764 }
765 return is_klass_loaded_by_klass_index(klass_index);
766 }
767
768
769 void Method::set_native_function(address function, bool post_event_flag) {
770 assert(function != NULL, "use clear_native_function to unregister natives");
771 assert(!is_method_handle_intrinsic() || function == SharedRuntime::native_method_throw_unsatisfied_link_error_entry(), "");
772 address* native_function = native_function_addr();
773
774 // We can see racers trying to place the same native function into place. Once
775 // is plenty.
776 address current = *native_function;
777 if (current == function) return;
778 if (post_event_flag && JvmtiExport::should_post_native_method_bind() &&
779 function != NULL) {
780 // native_method_throw_unsatisfied_link_error_entry() should only
781 // be passed when post_event_flag is false.
782 assert(function !=
783 SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
784 "post_event_flag mis-match");
785
786 // post the bind event, and possible change the bind function
787 JvmtiExport::post_native_method_bind(this, &function);
788 }
789 *native_function = function;
790 // This function can be called more than once. We must make sure that we always
791 // use the latest registered method -> check if a stub already has been generated.
792 // If so, we have to make it not_entrant.
793 CompiledMethod* nm = code(); // Put it into local variable to guard against concurrent updates
794 if (nm != NULL) {
795 nm->make_not_entrant();
796 }
797 }
798
799
800 bool Method::has_native_function() const {
801 if (is_method_handle_intrinsic())
802 return false; // special-cased in SharedRuntime::generate_native_wrapper
803 address func = native_function();
804 return (func != NULL && func != SharedRuntime::native_method_throw_unsatisfied_link_error_entry());
805 }
806
807
808 void Method::clear_native_function() {
809 // Note: is_method_handle_intrinsic() is allowed here.
810 set_native_function(
811 SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
812 !native_bind_event_is_interesting);
813 clear_code();
814 }
815
816 address Method::critical_native_function() {
817 methodHandle mh(this);
818 return NativeLookup::lookup_critical_entry(mh);
819 }
820
821
822 void Method::set_signature_handler(address handler) {
823 address* signature_handler = signature_handler_addr();
824 *signature_handler = handler;
825 }
826
827
828 void Method::print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason) {
829 if (PrintCompilation && report) {
830 ttyLocker ttyl;
831 tty->print("made not %scompilable on ", is_osr ? "OSR " : "");
832 if (comp_level == CompLevel_all) {
833 tty->print("all levels ");
834 } else {
835 tty->print("levels ");
836 for (int i = (int)CompLevel_none; i <= comp_level; i++) {
837 tty->print("%d ", i);
838 }
839 }
840 this->print_short_name(tty);
841 int size = this->code_size();
842 if (size > 0) {
843 tty->print(" (%d bytes)", size);
844 }
845 if (reason != NULL) {
846 tty->print(" %s", reason);
847 }
848 tty->cr();
849 }
850 if ((TraceDeoptimization || LogCompilation) && (xtty != NULL)) {
851 ttyLocker ttyl;
852 xtty->begin_elem("make_not_compilable thread='" UINTX_FORMAT "' osr='%d' level='%d'",
853 os::current_thread_id(), is_osr, comp_level);
854 if (reason != NULL) {
855 xtty->print(" reason=\'%s\'", reason);
856 }
857 xtty->method(this);
858 xtty->stamp();
859 xtty->end_elem();
860 }
861 }
862
863 bool Method::is_always_compilable() const {
864 // Generated adapters must be compiled
865 if (is_method_handle_intrinsic() && is_synthetic()) {
866 assert(!is_not_c1_compilable(), "sanity check");
867 assert(!is_not_c2_compilable(), "sanity check");
868 return true;
869 }
870
871 return false;
872 }
873
874 bool Method::is_not_compilable(int comp_level) const {
875 if (number_of_breakpoints() > 0)
876 return true;
877 if (is_always_compilable())
878 return false;
879 if (comp_level == CompLevel_any)
880 return is_not_c1_compilable() || is_not_c2_compilable();
881 if (is_c1_compile(comp_level))
882 return is_not_c1_compilable();
883 if (is_c2_compile(comp_level))
884 return is_not_c2_compilable();
885 return false;
886 }
887
888 // call this when compiler finds that this method is not compilable
889 void Method::set_not_compilable(int comp_level, bool report, const char* reason) {
890 if (is_always_compilable()) {
891 // Don't mark a method which should be always compilable
892 return;
893 }
894 print_made_not_compilable(comp_level, /*is_osr*/ false, report, reason);
895 if (comp_level == CompLevel_all) {
896 set_not_c1_compilable();
897 set_not_c2_compilable();
898 } else {
899 if (is_c1_compile(comp_level))
900 set_not_c1_compilable();
901 if (is_c2_compile(comp_level))
902 set_not_c2_compilable();
903 }
904 CompilationPolicy::policy()->disable_compilation(this);
905 assert(!CompilationPolicy::can_be_compiled(this, comp_level), "sanity check");
906 }
907
908 bool Method::is_not_osr_compilable(int comp_level) const {
909 if (is_not_compilable(comp_level))
910 return true;
911 if (comp_level == CompLevel_any)
912 return is_not_c1_osr_compilable() || is_not_c2_osr_compilable();
913 if (is_c1_compile(comp_level))
914 return is_not_c1_osr_compilable();
915 if (is_c2_compile(comp_level))
916 return is_not_c2_osr_compilable();
917 return false;
918 }
919
920 void Method::set_not_osr_compilable(int comp_level, bool report, const char* reason) {
921 print_made_not_compilable(comp_level, /*is_osr*/ true, report, reason);
922 if (comp_level == CompLevel_all) {
923 set_not_c1_osr_compilable();
924 set_not_c2_osr_compilable();
925 } else {
926 if (is_c1_compile(comp_level))
927 set_not_c1_osr_compilable();
928 if (is_c2_compile(comp_level))
929 set_not_c2_osr_compilable();
930 }
931 CompilationPolicy::policy()->disable_compilation(this);
932 assert(!CompilationPolicy::can_be_osr_compiled(this, comp_level), "sanity check");
933 }
934
935 // Revert to using the interpreter and clear out the nmethod
936 void Method::clear_code(bool acquire_lock /* = true */) {
937 MutexLockerEx pl(acquire_lock ? Patching_lock : NULL, Mutex::_no_safepoint_check_flag);
938 // this may be NULL if c2i adapters have not been made yet
939 // Only should happen at allocate time.
940 if (adapter() == NULL) {
941 _from_compiled_entry = NULL;
942 _from_compiled_value_entry = NULL;
943 _from_compiled_value_ro_entry = NULL;
944 } else {
945 _from_compiled_entry = adapter()->get_c2i_entry();
946 _from_compiled_value_entry = adapter()->get_c2i_value_entry();
947 _from_compiled_value_ro_entry = adapter()->get_c2i_value_ro_entry();
948 }
949 OrderAccess::storestore();
950 _from_interpreted_entry = _i2i_entry;
951 OrderAccess::storestore();
952 _code = NULL;
953 }
954
955 #if INCLUDE_CDS
956 // Called by class data sharing to remove any entry points (which are not shared)
957 void Method::unlink_method() {
958 _code = NULL;
959
960 assert(DumpSharedSpaces, "dump time only");
961 // Set the values to what they should be at run time. Note that
962 // this Method can no longer be executed during dump time.
963 _i2i_entry = Interpreter::entry_for_cds_method(this);
964 _from_interpreted_entry = _i2i_entry;
965
966 if (is_native()) {
967 *native_function_addr() = NULL;
968 set_signature_handler(NULL);
969 }
970 NOT_PRODUCT(set_compiled_invocation_count(0);)
971
972 CDSAdapterHandlerEntry* cds_adapter = (CDSAdapterHandlerEntry*)adapter();
973 constMethod()->set_adapter_trampoline(cds_adapter->get_adapter_trampoline());
974 _from_compiled_entry = cds_adapter->get_c2i_entry_trampoline();
975 assert(*((int*)_from_compiled_entry) == 0, "must be NULL during dump time, to be initialized at run time");
976 _from_compiled_value_entry = cds_adapter->get_c2i_entry_trampoline();
977 assert(*((int*)_from_compiled_value_entry) == 0, "must be NULL during dump time, to be initialized at run time");
978 _from_compiled_value_ro_entry = cds_adapter->get_c2i_entry_trampoline();
979 assert(*((int*)_from_compiled_value_ro_entry) == 0, "must be NULL during dump time, to be initialized at run time");
980
981 set_method_data(NULL);
982 clear_method_counters();
983 }
984 #endif
985
986 /****************************************************************************
987 // The following illustrates how the entries work for CDS shared Methods:
988 //
989 // Our goal is to delay writing into a shared Method until it's compiled.
990 // Hence, we want to determine the initial values for _i2i_entry,
991 // _from_interpreted_entry and _from_compiled_entry during CDS dump time.
992 //
993 // In this example, both Methods A and B have the _i2i_entry of "zero_locals".
994 // They also have similar signatures so that they will share the same
995 // AdapterHandlerEntry.
996 //
997 // _adapter_trampoline points to a fixed location in the RW section of
998 // the CDS archive. This location initially contains a NULL pointer. When the
999 // first of method A or B is linked, an AdapterHandlerEntry is allocated
1000 // dynamically, and its c2i/i2c entries are generated.
1001 //
1002 // _i2i_entry and _from_interpreted_entry initially points to the same
1003 // (fixed) location in the CODE section of the CDS archive. This contains
1004 // an unconditional branch to the actual entry for "zero_locals", which is
1005 // generated at run time and may be on an arbitrary address. Thus, the
1006 // unconditional branch is also generated at run time to jump to the correct
1007 // address.
1008 //
1009 // Similarly, _from_compiled_entry points to a fixed address in the CODE
1010 // section. This address has enough space for an unconditional branch
1011 // instruction, and is initially zero-filled. After the AdapterHandlerEntry is
1012 // initialized, and the address for the actual c2i_entry is known, we emit a
1013 // branch instruction here to branch to the actual c2i_entry.
1014 //
1015 // The effect of the extra branch on the i2i and c2i entries is negligible.
1016 //
1017 // The reason for putting _adapter_trampoline in RO is many shared Methods
1018 // share the same AdapterHandlerEntry, so we can save space in the RW section
1019 // by having the extra indirection.
1020
1021
1022 [Method A: RW]
1023 _constMethod ----> [ConstMethod: RO]
1024 _adapter_trampoline -----------+
1025 |
1026 _i2i_entry (same value as method B) |
1027 _from_interpreted_entry (same value as method B) |
1028 _from_compiled_entry (same value as method B) |
1029 |
1030 |
1031 [Method B: RW] +--------+
1032 _constMethod ----> [ConstMethod: RO] |
1033 _adapter_trampoline --+--->(AdapterHandlerEntry* ptr: RW)-+
1034 |
1035 +-------------------------------+
1036 |
1037 +----> [AdapterHandlerEntry] (allocated at run time)
1038 _fingerprint
1039 _c2i_entry ---------------------------------+->[c2i entry..]
1040 _i2i_entry -------------+ _i2c_entry ---------------+-> [i2c entry..] |
1041 _from_interpreted_entry | _c2i_unverified_entry | |
1042 | | | |
1043 | | (_cds_entry_table: CODE) | |
1044 | +->[0]: jmp _entry_table[0] --> (i2i_entry_for "zero_locals") | |
1045 | | (allocated at run time) | |
1046 | | ... [asm code ...] | |
1047 +-[not compiled]-+ [n]: jmp _entry_table[n] | |
1048 | | |
1049 | | |
1050 +-[compiled]-------------------------------------------------------------------+ |
1051 |
1052 _from_compiled_entry------------> (_c2i_entry_trampoline: CODE) |
1053 [jmp c2i_entry] ------------------------------------------------------+
1054
1055 ***/
1056
1057 // Called when the method_holder is getting linked. Setup entrypoints so the method
1058 // is ready to be called from interpreter, compiler, and vtables.
1059 void Method::link_method(const methodHandle& h_method, TRAPS) {
1060 // If the code cache is full, we may reenter this function for the
1061 // leftover methods that weren't linked.
1062 if (is_shared()) {
1063 address entry = Interpreter::entry_for_cds_method(h_method);
1064 assert(entry != NULL && entry == _i2i_entry,
1065 "should be correctly set during dump time");
1066 if (adapter() != NULL) {
1067 return;
1068 }
1069 assert(entry == _from_interpreted_entry,
1070 "should be correctly set during dump time");
1071 } else if (_i2i_entry != NULL) {
1072 return;
1073 }
1074 assert( _code == NULL, "nothing compiled yet" );
1075
1076 // Setup interpreter entrypoint
1077 assert(this == h_method(), "wrong h_method()" );
1078
1079 if (!is_shared()) {
1080 assert(adapter() == NULL, "init'd to NULL");
1081 address entry = Interpreter::entry_for_method(h_method);
1082 assert(entry != NULL, "interpreter entry must be non-null");
1083 // Sets both _i2i_entry and _from_interpreted_entry
1084 set_interpreter_entry(entry);
1085 }
1086
1087 // Don't overwrite already registered native entries.
1088 if (is_native() && !has_native_function()) {
1089 set_native_function(
1090 SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
1091 !native_bind_event_is_interesting);
1092 }
1093
1094 // Setup compiler entrypoint. This is made eagerly, so we do not need
1095 // special handling of vtables. An alternative is to make adapters more
1096 // lazily by calling make_adapter() from from_compiled_entry() for the
1097 // normal calls. For vtable calls life gets more complicated. When a
1098 // call-site goes mega-morphic we need adapters in all methods which can be
1099 // called from the vtable. We need adapters on such methods that get loaded
1100 // later. Ditto for mega-morphic itable calls. If this proves to be a
1101 // problem we'll make these lazily later.
1102 (void) make_adapters(h_method, CHECK);
1103
1104 // ONLY USE the h_method now as make_adapter may have blocked
1105
1106 }
1107
1108 address Method::make_adapters(const methodHandle& mh, TRAPS) {
1109 // Adapters for compiled code are made eagerly here. They are fairly
1110 // small (generally < 100 bytes) and quick to make (and cached and shared)
1111 // so making them eagerly shouldn't be too expensive.
1112 AdapterHandlerEntry* adapter = AdapterHandlerLibrary::get_adapter(mh);
1113 if (adapter == NULL ) {
1114 if (!is_init_completed()) {
1115 // Don't throw exceptions during VM initialization because java.lang.* classes
1116 // might not have been initialized, causing problems when constructing the
1117 // Java exception object.
1118 vm_exit_during_initialization("Out of space in CodeCache for adapters");
1119 } else {
1120 THROW_MSG_NULL(vmSymbols::java_lang_VirtualMachineError(), "Out of space in CodeCache for adapters");
1121 }
1122 }
1123
1124 if (mh->is_shared()) {
1125 assert(mh->adapter() == adapter, "must be");
1126 assert(mh->_from_compiled_entry != NULL, "must be");
1127 assert(mh->_from_compiled_value_entry != NULL, "must be");
1128 assert(mh->_from_compiled_value_ro_entry != NULL, "must be");
1129 } else {
1130 mh->set_adapter_entry(adapter);
1131 mh->_from_compiled_entry = adapter->get_c2i_entry();
1132 mh->_from_compiled_value_entry = adapter->get_c2i_value_entry();
1133 mh->_from_compiled_value_ro_entry = adapter->get_c2i_value_ro_entry();
1134 }
1135 return adapter->get_c2i_entry();
1136 }
1137
1138 void Method::restore_unshareable_info(TRAPS) {
1139 assert(is_method() && is_valid_method(this), "ensure C++ vtable is restored");
1140
1141 // Since restore_unshareable_info can be called more than once for a method, don't
1142 // redo any work.
1143 if (adapter() == NULL) {
1144 methodHandle mh(THREAD, this);
1145 link_method(mh, CHECK);
1146 }
1147 }
1148
1149 address Method::from_compiled_entry_no_trampoline() const {
1150 CompiledMethod *code = OrderAccess::load_acquire(&_code);
1151 if (code) {
1152 return code->verified_entry_point();
1153 } else {
1154 return adapter()->get_c2i_entry();
1155 }
1156 }
1157
1158 // The verified_code_entry() must be called when a invoke is resolved
1159 // on this method.
1160
1161 // It returns the compiled code entry point, after asserting not null.
1162 // This function is called after potential safepoints so that nmethod
1163 // or adapter that it points to is still live and valid.
1164 // This function must not hit a safepoint!
1165 address Method::verified_code_entry() {
1166 debug_only(NoSafepointVerifier nsv;)
1167 assert(_from_compiled_entry != NULL, "must be set");
1168 return _from_compiled_entry;
1169 }
1170
1171 address Method::verified_value_code_entry() {
1172 debug_only(NoSafepointVerifier nsv;)
1173 assert(_from_compiled_value_entry != NULL, "must be set");
1174 return _from_compiled_value_entry;
1175 }
1176
1177 address Method::verified_value_ro_code_entry() {
1178 debug_only(NoSafepointVerifier nsv;)
1179 assert(_from_compiled_value_ro_entry != NULL, "must be set");
1180 return _from_compiled_value_ro_entry;
1181 }
1182
1183 // Check that if an nmethod ref exists, it has a backlink to this or no backlink at all
1184 // (could be racing a deopt).
1185 // Not inline to avoid circular ref.
1186 bool Method::check_code() const {
1187 // cached in a register or local. There's a race on the value of the field.
1188 CompiledMethod *code = OrderAccess::load_acquire(&_code);
1189 return code == NULL || (code->method() == NULL) || (code->method() == (Method*)this && !code->is_osr_method());
1190 }
1191
1192 // Install compiled code. Instantly it can execute.
1193 void Method::set_code(const methodHandle& mh, CompiledMethod *code) {
1194 MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
1195 assert( code, "use clear_code to remove code" );
1196 assert( mh->check_code(), "" );
1197
1198 guarantee(mh->adapter() != NULL, "Adapter blob must already exist!");
1199
1200 // These writes must happen in this order, because the interpreter will
1201 // directly jump to from_interpreted_entry which jumps to an i2c adapter
1202 // which jumps to _from_compiled_entry.
1203 mh->_code = code; // Assign before allowing compiled code to exec
1204
1205 int comp_level = code->comp_level();
1206 // In theory there could be a race here. In practice it is unlikely
1207 // and not worth worrying about.
1208 if (comp_level > mh->highest_comp_level()) {
1209 mh->set_highest_comp_level(comp_level);
1210 }
1211
1212 OrderAccess::storestore();
1213 mh->_from_compiled_entry = code->verified_entry_point();
1214 mh->_from_compiled_value_entry = code->verified_value_entry_point();
1215 mh->_from_compiled_value_ro_entry = code->verified_value_ro_entry_point();
1216 OrderAccess::storestore();
1217 // Instantly compiled code can execute.
1218 if (!mh->is_method_handle_intrinsic())
1219 mh->_from_interpreted_entry = mh->get_i2c_entry();
1220 }
1221
1222
1223 bool Method::is_overridden_in(Klass* k) const {
1224 InstanceKlass* ik = InstanceKlass::cast(k);
1225
1226 if (ik->is_interface()) return false;
1227
1228 // If method is an interface, we skip it - except if it
1229 // is a miranda method
1230 if (method_holder()->is_interface()) {
1231 // Check that method is not a miranda method
1232 if (ik->lookup_method(name(), signature()) == NULL) {
1233 // No implementation exist - so miranda method
1234 return false;
1235 }
1236 return true;
1237 }
1238
1239 assert(ik->is_subclass_of(method_holder()), "should be subklass");
1240 if (!has_vtable_index()) {
1241 return false;
1242 } else {
1243 Method* vt_m = ik->method_at_vtable(vtable_index());
1244 return vt_m != this;
1245 }
1246 }
1247
1248
1249 // give advice about whether this Method* should be cached or not
1250 bool Method::should_not_be_cached() const {
1251 if (is_old()) {
1252 // This method has been redefined. It is either EMCP or obsolete
1253 // and we don't want to cache it because that would pin the method
1254 // down and prevent it from being collectible if and when it
1255 // finishes executing.
1256 return true;
1257 }
1258
1259 // caching this method should be just fine
1260 return false;
1261 }
1262
1263
1264 /**
1265 * Returns true if this is one of the specially treated methods for
1266 * security related stack walks (like Reflection.getCallerClass).
1267 */
1268 bool Method::is_ignored_by_security_stack_walk() const {
1269 if (intrinsic_id() == vmIntrinsics::_invoke) {
1270 // This is Method.invoke() -- ignore it
1271 return true;
1272 }
1273 if (method_holder()->is_subclass_of(SystemDictionary::reflect_MethodAccessorImpl_klass())) {
1274 // This is an auxilary frame -- ignore it
1275 return true;
1276 }
1277 if (is_method_handle_intrinsic() || is_compiled_lambda_form()) {
1278 // This is an internal adapter frame for method handles -- ignore it
1279 return true;
1280 }
1281 return false;
1282 }
1283
1284
1285 // Constant pool structure for invoke methods:
1286 enum {
1287 _imcp_invoke_name = 1, // utf8: 'invokeExact', etc.
1288 _imcp_invoke_signature, // utf8: (variable Symbol*)
1289 _imcp_limit
1290 };
1291
1292 // Test if this method is an MH adapter frame generated by Java code.
1293 // Cf. java/lang/invoke/InvokerBytecodeGenerator
1294 bool Method::is_compiled_lambda_form() const {
1295 return intrinsic_id() == vmIntrinsics::_compiledLambdaForm;
1296 }
1297
1298 // Test if this method is an internal MH primitive method.
1299 bool Method::is_method_handle_intrinsic() const {
1300 vmIntrinsics::ID iid = intrinsic_id();
1301 return (MethodHandles::is_signature_polymorphic(iid) &&
1302 MethodHandles::is_signature_polymorphic_intrinsic(iid));
1303 }
1304
1305 bool Method::has_member_arg() const {
1306 vmIntrinsics::ID iid = intrinsic_id();
1307 return (MethodHandles::is_signature_polymorphic(iid) &&
1308 MethodHandles::has_member_arg(iid));
1309 }
1310
1311 // Make an instance of a signature-polymorphic internal MH primitive.
1312 methodHandle Method::make_method_handle_intrinsic(vmIntrinsics::ID iid,
1313 Symbol* signature,
1314 TRAPS) {
1315 ResourceMark rm;
1316 methodHandle empty;
1317
1318 InstanceKlass* holder = SystemDictionary::MethodHandle_klass();
1319 Symbol* name = MethodHandles::signature_polymorphic_intrinsic_name(iid);
1320 assert(iid == MethodHandles::signature_polymorphic_name_id(name), "");
1321 if (TraceMethodHandles) {
1322 tty->print_cr("make_method_handle_intrinsic MH.%s%s", name->as_C_string(), signature->as_C_string());
1323 }
1324
1325 // invariant: cp->symbol_at_put is preceded by a refcount increment (more usually a lookup)
1326 name->increment_refcount();
1327 signature->increment_refcount();
1328
1329 int cp_length = _imcp_limit;
1330 ClassLoaderData* loader_data = holder->class_loader_data();
1331 constantPoolHandle cp;
1332 {
1333 ConstantPool* cp_oop = ConstantPool::allocate(loader_data, cp_length, CHECK_(empty));
1334 cp = constantPoolHandle(THREAD, cp_oop);
1335 }
1336 cp->set_pool_holder(holder);
1337 cp->symbol_at_put(_imcp_invoke_name, name);
1338 cp->symbol_at_put(_imcp_invoke_signature, signature);
1339 cp->set_has_preresolution();
1340
1341 // decide on access bits: public or not?
1342 int flags_bits = (JVM_ACC_NATIVE | JVM_ACC_SYNTHETIC | JVM_ACC_FINAL);
1343 bool must_be_static = MethodHandles::is_signature_polymorphic_static(iid);
1344 if (must_be_static) flags_bits |= JVM_ACC_STATIC;
1345 assert((flags_bits & JVM_ACC_PUBLIC) == 0, "do not expose these methods");
1346
1347 methodHandle m;
1348 {
1349 InlineTableSizes sizes;
1350 Method* m_oop = Method::allocate(loader_data, 0,
1351 accessFlags_from(flags_bits), &sizes,
1352 ConstMethod::NORMAL, CHECK_(empty));
1353 m = methodHandle(THREAD, m_oop);
1354 }
1355 m->set_constants(cp());
1356 m->set_name_index(_imcp_invoke_name);
1357 m->set_signature_index(_imcp_invoke_signature);
1358 assert(MethodHandles::is_signature_polymorphic_name(m->name()), "");
1359 assert(m->signature() == signature, "");
1360 ResultTypeFinder rtf(signature);
1361 m->constMethod()->set_result_type(rtf.type());
1362 m->compute_size_of_parameters(THREAD);
1363 m->init_intrinsic_id();
1364 assert(m->is_method_handle_intrinsic(), "");
1365 #ifdef ASSERT
1366 if (!MethodHandles::is_signature_polymorphic(m->intrinsic_id())) m->print();
1367 assert(MethodHandles::is_signature_polymorphic(m->intrinsic_id()), "must be an invoker");
1368 assert(m->intrinsic_id() == iid, "correctly predicted iid");
1369 #endif //ASSERT
1370
1371 // Finally, set up its entry points.
1372 assert(m->can_be_statically_bound(), "");
1373 m->set_vtable_index(Method::nonvirtual_vtable_index);
1374 m->link_method(m, CHECK_(empty));
1375
1376 if (TraceMethodHandles && (Verbose || WizardMode)) {
1377 ttyLocker ttyl;
1378 m->print_on(tty);
1379 }
1380
1381 return m;
1382 }
1383
1384 Klass* Method::check_non_bcp_klass(Klass* klass) {
1385 if (klass != NULL && klass->class_loader() != NULL) {
1386 if (klass->is_objArray_klass())
1387 klass = ObjArrayKlass::cast(klass)->bottom_klass();
1388 return klass;
1389 }
1390 return NULL;
1391 }
1392
1393
1394 methodHandle Method::clone_with_new_data(const methodHandle& m, u_char* new_code, int new_code_length,
1395 u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS) {
1396 // Code below does not work for native methods - they should never get rewritten anyway
1397 assert(!m->is_native(), "cannot rewrite native methods");
1398 // Allocate new Method*
1399 AccessFlags flags = m->access_flags();
1400
1401 ConstMethod* cm = m->constMethod();
1402 int checked_exceptions_len = cm->checked_exceptions_length();
1403 int localvariable_len = cm->localvariable_table_length();
1404 int exception_table_len = cm->exception_table_length();
1405 int method_parameters_len = cm->method_parameters_length();
1406 int method_annotations_len = cm->method_annotations_length();
1407 int parameter_annotations_len = cm->parameter_annotations_length();
1408 int type_annotations_len = cm->type_annotations_length();
1409 int default_annotations_len = cm->default_annotations_length();
1410
1411 InlineTableSizes sizes(
1412 localvariable_len,
1413 new_compressed_linenumber_size,
1414 exception_table_len,
1415 checked_exceptions_len,
1416 method_parameters_len,
1417 cm->generic_signature_index(),
1418 method_annotations_len,
1419 parameter_annotations_len,
1420 type_annotations_len,
1421 default_annotations_len,
1422 0);
1423
1424 ClassLoaderData* loader_data = m->method_holder()->class_loader_data();
1425 Method* newm_oop = Method::allocate(loader_data,
1426 new_code_length,
1427 flags,
1428 &sizes,
1429 m->method_type(),
1430 CHECK_(methodHandle()));
1431 methodHandle newm (THREAD, newm_oop);
1432
1433 // Create a shallow copy of Method part, but be careful to preserve the new ConstMethod*
1434 ConstMethod* newcm = newm->constMethod();
1435 int new_const_method_size = newm->constMethod()->size();
1436
1437 // This works because the source and target are both Methods. Some compilers
1438 // (e.g., clang) complain that the target vtable pointer will be stomped,
1439 // so cast away newm()'s and m()'s Methodness.
1440 memcpy((void*)newm(), (void*)m(), sizeof(Method));
1441
1442 // Create shallow copy of ConstMethod.
1443 memcpy(newcm, m->constMethod(), sizeof(ConstMethod));
1444
1445 // Reset correct method/const method, method size, and parameter info
1446 newm->set_constMethod(newcm);
1447 newm->constMethod()->set_code_size(new_code_length);
1448 newm->constMethod()->set_constMethod_size(new_const_method_size);
1449 assert(newm->code_size() == new_code_length, "check");
1450 assert(newm->method_parameters_length() == method_parameters_len, "check");
1451 assert(newm->checked_exceptions_length() == checked_exceptions_len, "check");
1452 assert(newm->exception_table_length() == exception_table_len, "check");
1453 assert(newm->localvariable_table_length() == localvariable_len, "check");
1454 // Copy new byte codes
1455 memcpy(newm->code_base(), new_code, new_code_length);
1456 // Copy line number table
1457 if (new_compressed_linenumber_size > 0) {
1458 memcpy(newm->compressed_linenumber_table(),
1459 new_compressed_linenumber_table,
1460 new_compressed_linenumber_size);
1461 }
1462 // Copy method_parameters
1463 if (method_parameters_len > 0) {
1464 memcpy(newm->method_parameters_start(),
1465 m->method_parameters_start(),
1466 method_parameters_len * sizeof(MethodParametersElement));
1467 }
1468 // Copy checked_exceptions
1469 if (checked_exceptions_len > 0) {
1470 memcpy(newm->checked_exceptions_start(),
1471 m->checked_exceptions_start(),
1472 checked_exceptions_len * sizeof(CheckedExceptionElement));
1473 }
1474 // Copy exception table
1475 if (exception_table_len > 0) {
1476 memcpy(newm->exception_table_start(),
1477 m->exception_table_start(),
1478 exception_table_len * sizeof(ExceptionTableElement));
1479 }
1480 // Copy local variable number table
1481 if (localvariable_len > 0) {
1482 memcpy(newm->localvariable_table_start(),
1483 m->localvariable_table_start(),
1484 localvariable_len * sizeof(LocalVariableTableElement));
1485 }
1486 // Copy stackmap table
1487 if (m->has_stackmap_table()) {
1488 int code_attribute_length = m->stackmap_data()->length();
1489 Array<u1>* stackmap_data =
1490 MetadataFactory::new_array<u1>(loader_data, code_attribute_length, 0, CHECK_NULL);
1491 memcpy((void*)stackmap_data->adr_at(0),
1492 (void*)m->stackmap_data()->adr_at(0), code_attribute_length);
1493 newm->set_stackmap_data(stackmap_data);
1494 }
1495
1496 // copy annotations over to new method
1497 newcm->copy_annotations_from(loader_data, cm, CHECK_NULL);
1498 return newm;
1499 }
1500
1501 vmSymbols::SID Method::klass_id_for_intrinsics(const Klass* holder) {
1502 // if loader is not the default loader (i.e., != NULL), we can't know the intrinsics
1503 // because we are not loading from core libraries
1504 // exception: the AES intrinsics come from lib/ext/sunjce_provider.jar
1505 // which does not use the class default class loader so we check for its loader here
1506 const InstanceKlass* ik = InstanceKlass::cast(holder);
1507 if ((ik->class_loader() != NULL) && !SystemDictionary::is_platform_class_loader(ik->class_loader())) {
1508 return vmSymbols::NO_SID; // regardless of name, no intrinsics here
1509 }
1510
1511 // see if the klass name is well-known:
1512 Symbol* klass_name = ik->name();
1513 return vmSymbols::find_sid(klass_name);
1514 }
1515
1516 void Method::init_intrinsic_id() {
1517 assert(_intrinsic_id == vmIntrinsics::_none, "do this just once");
1518 const uintptr_t max_id_uint = right_n_bits((int)(sizeof(_intrinsic_id) * BitsPerByte));
1519 assert((uintptr_t)vmIntrinsics::ID_LIMIT <= max_id_uint, "else fix size");
1520 assert(intrinsic_id_size_in_bytes() == sizeof(_intrinsic_id), "");
1521
1522 // the klass name is well-known:
1523 vmSymbols::SID klass_id = klass_id_for_intrinsics(method_holder());
1524 assert(klass_id != vmSymbols::NO_SID, "caller responsibility");
1525
1526 // ditto for method and signature:
1527 vmSymbols::SID name_id = vmSymbols::find_sid(name());
1528 if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1529 && klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle)
1530 && name_id == vmSymbols::NO_SID) {
1531 return;
1532 }
1533 vmSymbols::SID sig_id = vmSymbols::find_sid(signature());
1534 if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1535 && klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle)
1536 && sig_id == vmSymbols::NO_SID) {
1537 return;
1538 }
1539 jshort flags = access_flags().as_short();
1540
1541 vmIntrinsics::ID id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1542 if (id != vmIntrinsics::_none) {
1543 set_intrinsic_id(id);
1544 if (id == vmIntrinsics::_Class_cast) {
1545 // Even if the intrinsic is rejected, we want to inline this simple method.
1546 set_force_inline(true);
1547 }
1548 return;
1549 }
1550
1551 // A few slightly irregular cases:
1552 switch (klass_id) {
1553 case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_StrictMath):
1554 // Second chance: check in regular Math.
1555 switch (name_id) {
1556 case vmSymbols::VM_SYMBOL_ENUM_NAME(min_name):
1557 case vmSymbols::VM_SYMBOL_ENUM_NAME(max_name):
1558 case vmSymbols::VM_SYMBOL_ENUM_NAME(sqrt_name):
1559 // pretend it is the corresponding method in the non-strict class:
1560 klass_id = vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_Math);
1561 id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1562 break;
1563 default:
1564 break;
1565 }
1566 break;
1567
1568 // Signature-polymorphic methods: MethodHandle.invoke*, InvokeDynamic.*., VarHandle
1569 case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle):
1570 case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle):
1571 if (!is_native()) break;
1572 id = MethodHandles::signature_polymorphic_name_id(method_holder(), name());
1573 if (is_static() != MethodHandles::is_signature_polymorphic_static(id))
1574 id = vmIntrinsics::_none;
1575 break;
1576
1577 default:
1578 break;
1579 }
1580
1581 if (id != vmIntrinsics::_none) {
1582 // Set up its iid. It is an alias method.
1583 set_intrinsic_id(id);
1584 return;
1585 }
1586 }
1587
1588 // These two methods are static since a GC may move the Method
1589 bool Method::load_signature_classes(const methodHandle& m, TRAPS) {
1590 if (!THREAD->can_call_java()) {
1591 // There is nothing useful this routine can do from within the Compile thread.
1592 // Hopefully, the signature contains only well-known classes.
1593 // We could scan for this and return true/false, but the caller won't care.
1594 return false;
1595 }
1596 bool sig_is_loaded = true;
1597 Handle class_loader(THREAD, m->method_holder()->class_loader());
1598 Handle protection_domain(THREAD, m->method_holder()->protection_domain());
1599 ResourceMark rm(THREAD);
1600 Symbol* signature = m->signature();
1601 for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
1602 if (ss.is_object()) {
1603 Symbol* sym = ss.as_symbol(CHECK_(false));
1604 Symbol* name = sym;
1605 Klass* klass = SystemDictionary::resolve_or_null(name, class_loader,
1606 protection_domain, THREAD);
1607 // We are loading classes eagerly. If a ClassNotFoundException or
1608 // a LinkageError was generated, be sure to ignore it.
1609 if (HAS_PENDING_EXCEPTION) {
1610 if (PENDING_EXCEPTION->is_a(SystemDictionary::ClassNotFoundException_klass()) ||
1611 PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass())) {
1612 CLEAR_PENDING_EXCEPTION;
1613 } else {
1614 return false;
1615 }
1616 }
1617 if( klass == NULL) { sig_is_loaded = false; }
1618 }
1619 }
1620 return sig_is_loaded;
1621 }
1622
1623 bool Method::has_unloaded_classes_in_signature(const methodHandle& m, TRAPS) {
1624 Handle class_loader(THREAD, m->method_holder()->class_loader());
1625 Handle protection_domain(THREAD, m->method_holder()->protection_domain());
1626 ResourceMark rm(THREAD);
1627 Symbol* signature = m->signature();
1628 for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
1629 if (ss.type() == T_OBJECT) {
1630 Symbol* name = ss.as_symbol_or_null();
1631 if (name == NULL) return true;
1632 Klass* klass = SystemDictionary::find(name, class_loader, protection_domain, THREAD);
1633 if (klass == NULL) return true;
1634 }
1635 }
1636 return false;
1637 }
1638
1639 // Exposed so field engineers can debug VM
1640 void Method::print_short_name(outputStream* st) {
1641 ResourceMark rm;
1642 #ifdef PRODUCT
1643 st->print(" %s::", method_holder()->external_name());
1644 #else
1645 st->print(" %s::", method_holder()->internal_name());
1646 #endif
1647 name()->print_symbol_on(st);
1648 if (WizardMode) signature()->print_symbol_on(st);
1649 else if (MethodHandles::is_signature_polymorphic(intrinsic_id()))
1650 MethodHandles::print_as_basic_type_signature_on(st, signature(), true);
1651 }
1652
1653 // Comparer for sorting an object array containing
1654 // Method*s.
1655 static int method_comparator(Method* a, Method* b) {
1656 return a->name()->fast_compare(b->name());
1657 }
1658
1659 // This is only done during class loading, so it is OK to assume method_idnum matches the methods() array
1660 // default_methods also uses this without the ordering for fast find_method
1661 void Method::sort_methods(Array<Method*>* methods, bool set_idnums) {
1662 int length = methods->length();
1663 if (length > 1) {
1664 {
1665 NoSafepointVerifier nsv;
1666 QuickSort::sort(methods->data(), length, method_comparator, /*idempotent=*/false);
1667 }
1668 // Reset method ordering
1669 if (set_idnums) {
1670 for (int i = 0; i < length; i++) {
1671 Method* m = methods->at(i);
1672 m->set_method_idnum(i);
1673 m->set_orig_method_idnum(i);
1674 }
1675 }
1676 }
1677 }
1678
1679 //-----------------------------------------------------------------------------------
1680 // Non-product code unless JVM/TI needs it
1681
1682 #if !defined(PRODUCT) || INCLUDE_JVMTI
1683 class SignatureTypePrinter : public SignatureTypeNames {
1684 private:
1685 outputStream* _st;
1686 bool _use_separator;
1687
1688 void type_name(const char* name) {
1689 if (_use_separator) _st->print(", ");
1690 _st->print("%s", name);
1691 _use_separator = true;
1692 }
1693
1694 public:
1695 SignatureTypePrinter(Symbol* signature, outputStream* st) : SignatureTypeNames(signature) {
1696 _st = st;
1697 _use_separator = false;
1698 }
1699
1700 void print_parameters() { _use_separator = false; iterate_parameters(); }
1701 void print_returntype() { _use_separator = false; iterate_returntype(); }
1702 };
1703
1704
1705 void Method::print_name(outputStream* st) {
1706 Thread *thread = Thread::current();
1707 ResourceMark rm(thread);
1708 st->print("%s ", is_static() ? "static" : "virtual");
1709 if (WizardMode) {
1710 st->print("%s.", method_holder()->internal_name());
1711 name()->print_symbol_on(st);
1712 signature()->print_symbol_on(st);
1713 } else {
1714 SignatureTypePrinter sig(signature(), st);
1715 sig.print_returntype();
1716 st->print(" %s.", method_holder()->internal_name());
1717 name()->print_symbol_on(st);
1718 st->print("(");
1719 sig.print_parameters();
1720 st->print(")");
1721 }
1722 }
1723 #endif // !PRODUCT || INCLUDE_JVMTI
1724
1725
1726 void Method::print_codes_on(outputStream* st) const {
1727 print_codes_on(0, code_size(), st);
1728 }
1729
1730 void Method::print_codes_on(int from, int to, outputStream* st) const {
1731 Thread *thread = Thread::current();
1732 ResourceMark rm(thread);
1733 methodHandle mh (thread, (Method*)this);
1734 BytecodeStream s(mh);
1735 s.set_interval(from, to);
1736 BytecodeTracer::set_closure(BytecodeTracer::std_closure());
1737 while (s.next() >= 0) BytecodeTracer::trace(mh, s.bcp(), st);
1738 }
1739
1740 CompressedLineNumberReadStream::CompressedLineNumberReadStream(u_char* buffer) : CompressedReadStream(buffer) {
1741 _bci = 0;
1742 _line = 0;
1743 };
1744
1745 bool CompressedLineNumberReadStream::read_pair() {
1746 jubyte next = read_byte();
1747 // Check for terminator
1748 if (next == 0) return false;
1749 if (next == 0xFF) {
1750 // Escape character, regular compression used
1751 _bci += read_signed_int();
1752 _line += read_signed_int();
1753 } else {
1754 // Single byte compression used
1755 _bci += next >> 3;
1756 _line += next & 0x7;
1757 }
1758 return true;
1759 }
1760
1761 #if INCLUDE_JVMTI
1762
1763 Bytecodes::Code Method::orig_bytecode_at(int bci) const {
1764 BreakpointInfo* bp = method_holder()->breakpoints();
1765 for (; bp != NULL; bp = bp->next()) {
1766 if (bp->match(this, bci)) {
1767 return bp->orig_bytecode();
1768 }
1769 }
1770 {
1771 ResourceMark rm;
1772 fatal("no original bytecode found in %s at bci %d", name_and_sig_as_C_string(), bci);
1773 }
1774 return Bytecodes::_shouldnotreachhere;
1775 }
1776
1777 void Method::set_orig_bytecode_at(int bci, Bytecodes::Code code) {
1778 assert(code != Bytecodes::_breakpoint, "cannot patch breakpoints this way");
1779 BreakpointInfo* bp = method_holder()->breakpoints();
1780 for (; bp != NULL; bp = bp->next()) {
1781 if (bp->match(this, bci)) {
1782 bp->set_orig_bytecode(code);
1783 // and continue, in case there is more than one
1784 }
1785 }
1786 }
1787
1788 void Method::set_breakpoint(int bci) {
1789 InstanceKlass* ik = method_holder();
1790 BreakpointInfo *bp = new BreakpointInfo(this, bci);
1791 bp->set_next(ik->breakpoints());
1792 ik->set_breakpoints(bp);
1793 // do this last:
1794 bp->set(this);
1795 }
1796
1797 static void clear_matches(Method* m, int bci) {
1798 InstanceKlass* ik = m->method_holder();
1799 BreakpointInfo* prev_bp = NULL;
1800 BreakpointInfo* next_bp;
1801 for (BreakpointInfo* bp = ik->breakpoints(); bp != NULL; bp = next_bp) {
1802 next_bp = bp->next();
1803 // bci value of -1 is used to delete all breakpoints in method m (ex: clear_all_breakpoint).
1804 if (bci >= 0 ? bp->match(m, bci) : bp->match(m)) {
1805 // do this first:
1806 bp->clear(m);
1807 // unhook it
1808 if (prev_bp != NULL)
1809 prev_bp->set_next(next_bp);
1810 else
1811 ik->set_breakpoints(next_bp);
1812 delete bp;
1813 // When class is redefined JVMTI sets breakpoint in all versions of EMCP methods
1814 // at same location. So we have multiple matching (method_index and bci)
1815 // BreakpointInfo nodes in BreakpointInfo list. We should just delete one
1816 // breakpoint for clear_breakpoint request and keep all other method versions
1817 // BreakpointInfo for future clear_breakpoint request.
1818 // bcivalue of -1 is used to clear all breakpoints (see clear_all_breakpoints)
1819 // which is being called when class is unloaded. We delete all the Breakpoint
1820 // information for all versions of method. We may not correctly restore the original
1821 // bytecode in all method versions, but that is ok. Because the class is being unloaded
1822 // so these methods won't be used anymore.
1823 if (bci >= 0) {
1824 break;
1825 }
1826 } else {
1827 // This one is a keeper.
1828 prev_bp = bp;
1829 }
1830 }
1831 }
1832
1833 void Method::clear_breakpoint(int bci) {
1834 assert(bci >= 0, "");
1835 clear_matches(this, bci);
1836 }
1837
1838 void Method::clear_all_breakpoints() {
1839 clear_matches(this, -1);
1840 }
1841
1842 #endif // INCLUDE_JVMTI
1843
1844 int Method::invocation_count() {
1845 MethodCounters *mcs = method_counters();
1846 if (TieredCompilation) {
1847 MethodData* const mdo = method_data();
1848 if (((mcs != NULL) ? mcs->invocation_counter()->carry() : false) ||
1849 ((mdo != NULL) ? mdo->invocation_counter()->carry() : false)) {
1850 return InvocationCounter::count_limit;
1851 } else {
1852 return ((mcs != NULL) ? mcs->invocation_counter()->count() : 0) +
1853 ((mdo != NULL) ? mdo->invocation_counter()->count() : 0);
1854 }
1855 } else {
1856 return (mcs == NULL) ? 0 : mcs->invocation_counter()->count();
1857 }
1858 }
1859
1860 int Method::backedge_count() {
1861 MethodCounters *mcs = method_counters();
1862 if (TieredCompilation) {
1863 MethodData* const mdo = method_data();
1864 if (((mcs != NULL) ? mcs->backedge_counter()->carry() : false) ||
1865 ((mdo != NULL) ? mdo->backedge_counter()->carry() : false)) {
1866 return InvocationCounter::count_limit;
1867 } else {
1868 return ((mcs != NULL) ? mcs->backedge_counter()->count() : 0) +
1869 ((mdo != NULL) ? mdo->backedge_counter()->count() : 0);
1870 }
1871 } else {
1872 return (mcs == NULL) ? 0 : mcs->backedge_counter()->count();
1873 }
1874 }
1875
1876 int Method::highest_comp_level() const {
1877 const MethodCounters* mcs = method_counters();
1878 if (mcs != NULL) {
1879 return mcs->highest_comp_level();
1880 } else {
1881 return CompLevel_none;
1882 }
1883 }
1884
1885 int Method::highest_osr_comp_level() const {
1886 const MethodCounters* mcs = method_counters();
1887 if (mcs != NULL) {
1888 return mcs->highest_osr_comp_level();
1889 } else {
1890 return CompLevel_none;
1891 }
1892 }
1893
1894 void Method::set_highest_comp_level(int level) {
1895 MethodCounters* mcs = method_counters();
1896 if (mcs != NULL) {
1897 mcs->set_highest_comp_level(level);
1898 }
1899 }
1900
1901 void Method::set_highest_osr_comp_level(int level) {
1902 MethodCounters* mcs = method_counters();
1903 if (mcs != NULL) {
1904 mcs->set_highest_osr_comp_level(level);
1905 }
1906 }
1907
1908 #if INCLUDE_JVMTI
1909
1910 BreakpointInfo::BreakpointInfo(Method* m, int bci) {
1911 _bci = bci;
1912 _name_index = m->name_index();
1913 _signature_index = m->signature_index();
1914 _orig_bytecode = (Bytecodes::Code) *m->bcp_from(_bci);
1915 if (_orig_bytecode == Bytecodes::_breakpoint)
1916 _orig_bytecode = m->orig_bytecode_at(_bci);
1917 _next = NULL;
1918 }
1919
1920 void BreakpointInfo::set(Method* method) {
1921 #ifdef ASSERT
1922 {
1923 Bytecodes::Code code = (Bytecodes::Code) *method->bcp_from(_bci);
1924 if (code == Bytecodes::_breakpoint)
1925 code = method->orig_bytecode_at(_bci);
1926 assert(orig_bytecode() == code, "original bytecode must be the same");
1927 }
1928 #endif
1929 Thread *thread = Thread::current();
1930 *method->bcp_from(_bci) = Bytecodes::_breakpoint;
1931 method->incr_number_of_breakpoints(thread);
1932 SystemDictionary::notice_modification();
1933 {
1934 // Deoptimize all dependents on this method
1935 HandleMark hm(thread);
1936 methodHandle mh(thread, method);
1937 CodeCache::flush_dependents_on_method(mh);
1938 }
1939 }
1940
1941 void BreakpointInfo::clear(Method* method) {
1942 *method->bcp_from(_bci) = orig_bytecode();
1943 assert(method->number_of_breakpoints() > 0, "must not go negative");
1944 method->decr_number_of_breakpoints(Thread::current());
1945 }
1946
1947 #endif // INCLUDE_JVMTI
1948
1949 // jmethodID handling
1950
1951 // This is a block allocating object, sort of like JNIHandleBlock, only a
1952 // lot simpler.
1953 // It's allocated on the CHeap because once we allocate a jmethodID, we can
1954 // never get rid of it.
1955
1956 static const int min_block_size = 8;
1957
1958 class JNIMethodBlockNode : public CHeapObj<mtClass> {
1959 friend class JNIMethodBlock;
1960 Method** _methods;
1961 int _number_of_methods;
1962 int _top;
1963 JNIMethodBlockNode* _next;
1964
1965 public:
1966
1967 JNIMethodBlockNode(int num_methods = min_block_size);
1968
1969 ~JNIMethodBlockNode() { FREE_C_HEAP_ARRAY(Method*, _methods); }
1970
1971 void ensure_methods(int num_addl_methods) {
1972 if (_top < _number_of_methods) {
1973 num_addl_methods -= _number_of_methods - _top;
1974 if (num_addl_methods <= 0) {
1975 return;
1976 }
1977 }
1978 if (_next == NULL) {
1979 _next = new JNIMethodBlockNode(MAX2(num_addl_methods, min_block_size));
1980 } else {
1981 _next->ensure_methods(num_addl_methods);
1982 }
1983 }
1984 };
1985
1986 class JNIMethodBlock : public CHeapObj<mtClass> {
1987 JNIMethodBlockNode _head;
1988 JNIMethodBlockNode *_last_free;
1989 public:
1990 static Method* const _free_method;
1991
1992 JNIMethodBlock(int initial_capacity = min_block_size)
1993 : _head(initial_capacity), _last_free(&_head) {}
1994
1995 void ensure_methods(int num_addl_methods) {
1996 _last_free->ensure_methods(num_addl_methods);
1997 }
1998
1999 Method** add_method(Method* m) {
2000 for (JNIMethodBlockNode* b = _last_free; b != NULL; b = b->_next) {
2001 if (b->_top < b->_number_of_methods) {
2002 // top points to the next free entry.
2003 int i = b->_top;
2004 b->_methods[i] = m;
2005 b->_top++;
2006 _last_free = b;
2007 return &(b->_methods[i]);
2008 } else if (b->_top == b->_number_of_methods) {
2009 // if the next free entry ran off the block see if there's a free entry
2010 for (int i = 0; i < b->_number_of_methods; i++) {
2011 if (b->_methods[i] == _free_method) {
2012 b->_methods[i] = m;
2013 _last_free = b;
2014 return &(b->_methods[i]);
2015 }
2016 }
2017 // Only check each block once for frees. They're very unlikely.
2018 // Increment top past the end of the block.
2019 b->_top++;
2020 }
2021 // need to allocate a next block.
2022 if (b->_next == NULL) {
2023 b->_next = _last_free = new JNIMethodBlockNode();
2024 }
2025 }
2026 guarantee(false, "Should always allocate a free block");
2027 return NULL;
2028 }
2029
2030 bool contains(Method** m) {
2031 if (m == NULL) return false;
2032 for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2033 if (b->_methods <= m && m < b->_methods + b->_number_of_methods) {
2034 // This is a bit of extra checking, for two reasons. One is
2035 // that contains() deals with pointers that are passed in by
2036 // JNI code, so making sure that the pointer is aligned
2037 // correctly is valuable. The other is that <= and > are
2038 // technically not defined on pointers, so the if guard can
2039 // pass spuriously; no modern compiler is likely to make that
2040 // a problem, though (and if one did, the guard could also
2041 // fail spuriously, which would be bad).
2042 ptrdiff_t idx = m - b->_methods;
2043 if (b->_methods + idx == m) {
2044 return true;
2045 }
2046 }
2047 }
2048 return false; // not found
2049 }
2050
2051 // Doesn't really destroy it, just marks it as free so it can be reused.
2052 void destroy_method(Method** m) {
2053 #ifdef ASSERT
2054 assert(contains(m), "should be a methodID");
2055 #endif // ASSERT
2056 *m = _free_method;
2057 }
2058
2059 // During class unloading the methods are cleared, which is different
2060 // than freed.
2061 void clear_all_methods() {
2062 for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2063 for (int i = 0; i< b->_number_of_methods; i++) {
2064 b->_methods[i] = NULL;
2065 }
2066 }
2067 }
2068 #ifndef PRODUCT
2069 int count_methods() {
2070 // count all allocated methods
2071 int count = 0;
2072 for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2073 for (int i = 0; i< b->_number_of_methods; i++) {
2074 if (b->_methods[i] != _free_method) count++;
2075 }
2076 }
2077 return count;
2078 }
2079 #endif // PRODUCT
2080 };
2081
2082 // Something that can't be mistaken for an address or a markOop
2083 Method* const JNIMethodBlock::_free_method = (Method*)55;
2084
2085 JNIMethodBlockNode::JNIMethodBlockNode(int num_methods) : _top(0), _next(NULL) {
2086 _number_of_methods = MAX2(num_methods, min_block_size);
2087 _methods = NEW_C_HEAP_ARRAY(Method*, _number_of_methods, mtInternal);
2088 for (int i = 0; i < _number_of_methods; i++) {
2089 _methods[i] = JNIMethodBlock::_free_method;
2090 }
2091 }
2092
2093 void Method::ensure_jmethod_ids(ClassLoaderData* loader_data, int capacity) {
2094 ClassLoaderData* cld = loader_data;
2095 if (!SafepointSynchronize::is_at_safepoint()) {
2096 // Have to add jmethod_ids() to class loader data thread-safely.
2097 // Also have to add the method to the list safely, which the cld lock
2098 // protects as well.
2099 MutexLockerEx ml(cld->metaspace_lock(), Mutex::_no_safepoint_check_flag);
2100 if (cld->jmethod_ids() == NULL) {
2101 cld->set_jmethod_ids(new JNIMethodBlock(capacity));
2102 } else {
2103 cld->jmethod_ids()->ensure_methods(capacity);
2104 }
2105 } else {
2106 // At safepoint, we are single threaded and can set this.
2107 if (cld->jmethod_ids() == NULL) {
2108 cld->set_jmethod_ids(new JNIMethodBlock(capacity));
2109 } else {
2110 cld->jmethod_ids()->ensure_methods(capacity);
2111 }
2112 }
2113 }
2114
2115 // Add a method id to the jmethod_ids
2116 jmethodID Method::make_jmethod_id(ClassLoaderData* loader_data, Method* m) {
2117 ClassLoaderData* cld = loader_data;
2118
2119 if (!SafepointSynchronize::is_at_safepoint()) {
2120 // Have to add jmethod_ids() to class loader data thread-safely.
2121 // Also have to add the method to the list safely, which the cld lock
2122 // protects as well.
2123 MutexLockerEx ml(cld->metaspace_lock(), Mutex::_no_safepoint_check_flag);
2124 if (cld->jmethod_ids() == NULL) {
2125 cld->set_jmethod_ids(new JNIMethodBlock());
2126 }
2127 // jmethodID is a pointer to Method*
2128 return (jmethodID)cld->jmethod_ids()->add_method(m);
2129 } else {
2130 // At safepoint, we are single threaded and can set this.
2131 if (cld->jmethod_ids() == NULL) {
2132 cld->set_jmethod_ids(new JNIMethodBlock());
2133 }
2134 // jmethodID is a pointer to Method*
2135 return (jmethodID)cld->jmethod_ids()->add_method(m);
2136 }
2137 }
2138
2139 // Mark a jmethodID as free. This is called when there is a data race in
2140 // InstanceKlass while creating the jmethodID cache.
2141 void Method::destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID m) {
2142 ClassLoaderData* cld = loader_data;
2143 Method** ptr = (Method**)m;
2144 assert(cld->jmethod_ids() != NULL, "should have method handles");
2145 cld->jmethod_ids()->destroy_method(ptr);
2146 }
2147
2148 void Method::change_method_associated_with_jmethod_id(jmethodID jmid, Method* new_method) {
2149 // Can't assert the method_holder is the same because the new method has the
2150 // scratch method holder.
2151 assert(resolve_jmethod_id(jmid)->method_holder()->class_loader()
2152 == new_method->method_holder()->class_loader() ||
2153 new_method->method_holder()->class_loader() == NULL, // allow Unsafe substitution
2154 "changing to a different class loader");
2155 // Just change the method in place, jmethodID pointer doesn't change.
2156 *((Method**)jmid) = new_method;
2157 }
2158
2159 bool Method::is_method_id(jmethodID mid) {
2160 Method* m = resolve_jmethod_id(mid);
2161 assert(m != NULL, "should be called with non-null method");
2162 InstanceKlass* ik = m->method_holder();
2163 ClassLoaderData* cld = ik->class_loader_data();
2164 if (cld->jmethod_ids() == NULL) return false;
2165 return (cld->jmethod_ids()->contains((Method**)mid));
2166 }
2167
2168 Method* Method::checked_resolve_jmethod_id(jmethodID mid) {
2169 if (mid == NULL) return NULL;
2170 Method* o = resolve_jmethod_id(mid);
2171 if (o == NULL || o == JNIMethodBlock::_free_method || !((Metadata*)o)->is_method()) {
2172 return NULL;
2173 }
2174 return o;
2175 };
2176
2177 void Method::set_on_stack(const bool value) {
2178 // Set both the method itself and its constant pool. The constant pool
2179 // on stack means some method referring to it is also on the stack.
2180 constants()->set_on_stack(value);
2181
2182 bool already_set = on_stack();
2183 _access_flags.set_on_stack(value);
2184 if (value && !already_set) {
2185 MetadataOnStackMark::record(this);
2186 }
2187 assert(!value || !is_old() || is_obsolete() || is_running_emcp(),
2188 "emcp methods cannot run after emcp bit is cleared");
2189 }
2190
2191 // Called when the class loader is unloaded to make all methods weak.
2192 void Method::clear_jmethod_ids(ClassLoaderData* loader_data) {
2193 loader_data->jmethod_ids()->clear_all_methods();
2194 }
2195
2196 bool Method::has_method_vptr(const void* ptr) {
2197 Method m;
2198 // This assumes that the vtbl pointer is the first word of a C++ object.
2199 return dereference_vptr(&m) == dereference_vptr(ptr);
2200 }
2201
2202 // Check that this pointer is valid by checking that the vtbl pointer matches
2203 bool Method::is_valid_method(const Method* m) {
2204 if (m == NULL) {
2205 return false;
2206 } else if ((intptr_t(m) & (wordSize-1)) != 0) {
2207 // Quick sanity check on pointer.
2208 return false;
2209 } else if (m->is_shared()) {
2210 return MetaspaceShared::is_valid_shared_method(m);
2211 } else if (Metaspace::contains_non_shared(m)) {
2212 return has_method_vptr((const void*)m);
2213 } else {
2214 return false;
2215 }
2216 }
2217
2218 #ifndef PRODUCT
2219 void Method::print_jmethod_ids(const ClassLoaderData* loader_data, outputStream* out) {
2220 out->print(" jni_method_id count = %d", loader_data->jmethod_ids()->count_methods());
2221 }
2222 #endif // PRODUCT
2223
2224
2225 // Printing
2226
2227 #ifndef PRODUCT
2228
2229 void Method::print_on(outputStream* st) const {
2230 ResourceMark rm;
2231 assert(is_method(), "must be method");
2232 st->print_cr("%s", internal_name());
2233 st->print_cr(" - this oop: " INTPTR_FORMAT, p2i(this));
2234 st->print (" - method holder: "); method_holder()->print_value_on(st); st->cr();
2235 st->print (" - constants: " INTPTR_FORMAT " ", p2i(constants()));
2236 constants()->print_value_on(st); st->cr();
2237 st->print (" - access: 0x%x ", access_flags().as_int()); access_flags().print_on(st); st->cr();
2238 st->print (" - name: "); name()->print_value_on(st); st->cr();
2239 st->print (" - signature: "); signature()->print_value_on(st); st->cr();
2240 st->print_cr(" - max stack: %d", max_stack());
2241 st->print_cr(" - max locals: %d", max_locals());
2242 st->print_cr(" - size of params: %d", size_of_parameters());
2243 st->print_cr(" - method size: %d", method_size());
2244 if (intrinsic_id() != vmIntrinsics::_none)
2245 st->print_cr(" - intrinsic id: %d %s", intrinsic_id(), vmIntrinsics::name_at(intrinsic_id()));
2246 if (highest_comp_level() != CompLevel_none)
2247 st->print_cr(" - highest level: %d", highest_comp_level());
2248 st->print_cr(" - vtable index: %d", _vtable_index);
2249 if (valid_itable_index())
2250 st->print_cr(" - itable index: %d", itable_index());
2251 st->print_cr(" - i2i entry: " INTPTR_FORMAT, p2i(interpreter_entry()));
2252 st->print( " - adapters: ");
2253 AdapterHandlerEntry* a = ((Method*)this)->adapter();
2254 if (a == NULL)
2255 st->print_cr(INTPTR_FORMAT, p2i(a));
2256 else
2257 a->print_adapter_on(st);
2258 st->print_cr(" - compiled entry " INTPTR_FORMAT, p2i(from_compiled_entry()));
2259 st->print_cr(" - code size: %d", code_size());
2260 if (code_size() != 0) {
2261 st->print_cr(" - code start: " INTPTR_FORMAT, p2i(code_base()));
2262 st->print_cr(" - code end (excl): " INTPTR_FORMAT, p2i(code_base() + code_size()));
2263 }
2264 if (method_data() != NULL) {
2265 st->print_cr(" - method data: " INTPTR_FORMAT, p2i(method_data()));
2266 }
2267 st->print_cr(" - checked ex length: %d", checked_exceptions_length());
2268 if (checked_exceptions_length() > 0) {
2269 CheckedExceptionElement* table = checked_exceptions_start();
2270 st->print_cr(" - checked ex start: " INTPTR_FORMAT, p2i(table));
2271 if (Verbose) {
2272 for (int i = 0; i < checked_exceptions_length(); i++) {
2273 st->print_cr(" - throws %s", constants()->printable_name_at(table[i].class_cp_index));
2274 }
2275 }
2276 }
2277 if (has_linenumber_table()) {
2278 u_char* table = compressed_linenumber_table();
2279 st->print_cr(" - linenumber start: " INTPTR_FORMAT, p2i(table));
2280 if (Verbose) {
2281 CompressedLineNumberReadStream stream(table);
2282 while (stream.read_pair()) {
2283 st->print_cr(" - line %d: %d", stream.line(), stream.bci());
2284 }
2285 }
2286 }
2287 st->print_cr(" - localvar length: %d", localvariable_table_length());
2288 if (localvariable_table_length() > 0) {
2289 LocalVariableTableElement* table = localvariable_table_start();
2290 st->print_cr(" - localvar start: " INTPTR_FORMAT, p2i(table));
2291 if (Verbose) {
2292 for (int i = 0; i < localvariable_table_length(); i++) {
2293 int bci = table[i].start_bci;
2294 int len = table[i].length;
2295 const char* name = constants()->printable_name_at(table[i].name_cp_index);
2296 const char* desc = constants()->printable_name_at(table[i].descriptor_cp_index);
2297 int slot = table[i].slot;
2298 st->print_cr(" - %s %s bci=%d len=%d slot=%d", desc, name, bci, len, slot);
2299 }
2300 }
2301 }
2302 if (code() != NULL) {
2303 st->print (" - compiled code: ");
2304 code()->print_value_on(st);
2305 }
2306 if (is_native()) {
2307 st->print_cr(" - native function: " INTPTR_FORMAT, p2i(native_function()));
2308 st->print_cr(" - signature handler: " INTPTR_FORMAT, p2i(signature_handler()));
2309 }
2310 }
2311
2312 void Method::print_linkage_flags(outputStream* st) {
2313 access_flags().print_on(st);
2314 if (is_default_method()) {
2315 st->print("default ");
2316 }
2317 if (is_overpass()) {
2318 st->print("overpass ");
2319 }
2320 }
2321 #endif //PRODUCT
2322
2323 void Method::print_value_on(outputStream* st) const {
2324 assert(is_method(), "must be method");
2325 st->print("%s", internal_name());
2326 print_address_on(st);
2327 st->print(" ");
2328 if (WizardMode) access_flags().print_on(st);
2329 name()->print_value_on(st);
2330 st->print(" ");
2331 signature()->print_value_on(st);
2332 st->print(" in ");
2333 method_holder()->print_value_on(st);
2334 if (WizardMode) st->print("#%d", _vtable_index);
2335 if (WizardMode) st->print("[%d,%d]", size_of_parameters(), max_locals());
2336 if (WizardMode && code() != NULL) st->print(" ((nmethod*)%p)", code());
2337 }
2338
2339 #if INCLUDE_SERVICES
2340 // Size Statistics
2341 void Method::collect_statistics(KlassSizeStats *sz) const {
2342 int mysize = sz->count(this);
2343 sz->_method_bytes += mysize;
2344 sz->_method_all_bytes += mysize;
2345 sz->_rw_bytes += mysize;
2346
2347 if (constMethod()) {
2348 constMethod()->collect_statistics(sz);
2349 }
2350 if (method_data()) {
2351 method_data()->collect_statistics(sz);
2352 }
2353 }
2354 #endif // INCLUDE_SERVICES
2355
2356 // LogTouchedMethods and PrintTouchedMethods
2357
2358 // TouchedMethodRecord -- we can't use a HashtableEntry<Method*> because
2359 // the Method may be garbage collected. Let's roll our own hash table.
2360 class TouchedMethodRecord : CHeapObj<mtTracing> {
2361 public:
2362 // It's OK to store Symbols here because they will NOT be GC'ed if
2363 // LogTouchedMethods is enabled.
2364 TouchedMethodRecord* _next;
2365 Symbol* _class_name;
2366 Symbol* _method_name;
2367 Symbol* _method_signature;
2368 };
2369
2370 static const int TOUCHED_METHOD_TABLE_SIZE = 20011;
2371 static TouchedMethodRecord** _touched_method_table = NULL;
2372
2373 void Method::log_touched(TRAPS) {
2374
2375 const int table_size = TOUCHED_METHOD_TABLE_SIZE;
2376 Symbol* my_class = klass_name();
2377 Symbol* my_name = name();
2378 Symbol* my_sig = signature();
2379
2380 unsigned int hash = my_class->identity_hash() +
2381 my_name->identity_hash() +
2382 my_sig->identity_hash();
2383 juint index = juint(hash) % table_size;
2384
2385 MutexLocker ml(TouchedMethodLog_lock, THREAD);
2386 if (_touched_method_table == NULL) {
2387 _touched_method_table = NEW_C_HEAP_ARRAY2(TouchedMethodRecord*, table_size,
2388 mtTracing, CURRENT_PC);
2389 memset(_touched_method_table, 0, sizeof(TouchedMethodRecord*)*table_size);
2390 }
2391
2392 TouchedMethodRecord* ptr = _touched_method_table[index];
2393 while (ptr) {
2394 if (ptr->_class_name == my_class &&
2395 ptr->_method_name == my_name &&
2396 ptr->_method_signature == my_sig) {
2397 return;
2398 }
2399 if (ptr->_next == NULL) break;
2400 ptr = ptr->_next;
2401 }
2402 TouchedMethodRecord* nptr = NEW_C_HEAP_OBJ(TouchedMethodRecord, mtTracing);
2403 my_class->increment_refcount();
2404 my_name->increment_refcount();
2405 my_sig->increment_refcount();
2406 nptr->_class_name = my_class;
2407 nptr->_method_name = my_name;
2408 nptr->_method_signature = my_sig;
2409 nptr->_next = NULL;
2410
2411 if (ptr == NULL) {
2412 // first
2413 _touched_method_table[index] = nptr;
2414 } else {
2415 ptr->_next = nptr;
2416 }
2417 }
2418
2419 void Method::print_touched_methods(outputStream* out) {
2420 MutexLockerEx ml(Thread::current()->is_VM_thread() ? NULL : TouchedMethodLog_lock);
2421 out->print_cr("# Method::print_touched_methods version 1");
2422 if (_touched_method_table) {
2423 for (int i = 0; i < TOUCHED_METHOD_TABLE_SIZE; i++) {
2424 TouchedMethodRecord* ptr = _touched_method_table[i];
2425 while(ptr) {
2426 ptr->_class_name->print_symbol_on(out); out->print(".");
2427 ptr->_method_name->print_symbol_on(out); out->print(":");
2428 ptr->_method_signature->print_symbol_on(out); out->cr();
2429 ptr = ptr->_next;
2430 }
2431 }
2432 }
2433 }
2434
2435 // Verification
2436
2437 void Method::verify_on(outputStream* st) {
2438 guarantee(is_method(), "object must be method");
2439 guarantee(constants()->is_constantPool(), "should be constant pool");
2440 MethodData* md = method_data();
2441 guarantee(md == NULL ||
2442 md->is_methodData(), "should be method data");
2443 }