1 /*
2 * Copyright (c) 1997, 2018, 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/metadataOnStackMark.hpp"
27 #include "classfile/systemDictionary.hpp"
28 #include "code/codeCache.hpp"
29 #include "code/debugInfoRec.hpp"
30 #include "gc/shared/collectedHeap.inline.hpp"
31 #include "interpreter/bytecodeStream.hpp"
32 #include "interpreter/bytecodeTracer.hpp"
33 #include "interpreter/bytecodes.hpp"
34 #include "interpreter/interpreter.hpp"
35 #include "interpreter/oopMapCache.hpp"
36 #include "memory/allocation.inline.hpp"
37 #include "memory/heapInspection.hpp"
38 #include "memory/metadataFactory.hpp"
39 #include "memory/metaspaceClosure.hpp"
40 #include "memory/metaspaceShared.hpp"
41 #include "memory/oopFactory.hpp"
42 #include "memory/resourceArea.hpp"
43 #include "oops/constMethod.hpp"
44 #include "oops/method.inline.hpp"
45 #include "oops/methodData.hpp"
46 #include "oops/objArrayOop.inline.hpp"
47 #include "oops/oop.inline.hpp"
48 #include "oops/symbol.hpp"
49 #include "prims/jvmtiExport.hpp"
50 #include "prims/methodHandles.hpp"
51 #include "prims/nativeLookup.hpp"
52 #include "runtime/arguments.hpp"
53 #include "runtime/compilationPolicy.hpp"
54 #include "runtime/frame.inline.hpp"
55 #include "runtime/handles.inline.hpp"
56 #include "runtime/init.hpp"
57 #include "runtime/orderAccess.hpp"
58 #include "runtime/relocator.hpp"
59 #include "runtime/safepointVerifiers.hpp"
60 #include "runtime/sharedRuntime.hpp"
61 #include "runtime/signature.hpp"
62 #include "utilities/align.hpp"
63 #include "utilities/quickSort.hpp"
64 #include "utilities/vmError.hpp"
65 #include "utilities/xmlstream.hpp"
66
67 // Implementation of Method
68
69 Method* Method::allocate(ClassLoaderData* loader_data,
70 int byte_code_size,
71 AccessFlags access_flags,
72 InlineTableSizes* sizes,
73 ConstMethod::MethodType method_type,
74 TRAPS) {
75 assert(!access_flags.is_native() || byte_code_size == 0,
76 "native methods should not contain byte codes");
77 ConstMethod* cm = ConstMethod::allocate(loader_data,
78 byte_code_size,
79 sizes,
80 method_type,
81 CHECK_NULL);
82 int size = Method::size(access_flags.is_native());
83 return new (loader_data, size, MetaspaceObj::MethodType, THREAD) Method(cm, access_flags);
84 }
85
86 Method::Method(ConstMethod* xconst, AccessFlags access_flags) {
87 NoSafepointVerifier no_safepoint;
88 set_constMethod(xconst);
89 set_access_flags(access_flags);
90 set_intrinsic_id(vmIntrinsics::_none);
91 set_force_inline(false);
92 set_hidden(false);
93 set_dont_inline(false);
94 set_has_injected_profile(false);
95 set_method_data(NULL);
96 clear_method_counters();
97 set_vtable_index(Method::garbage_vtable_index);
98
99 // Fix and bury in Method*
100 set_interpreter_entry(NULL); // sets i2i entry and from_int
101 set_adapter_entry(NULL);
102 clear_code(false /* don't need a lock */); // from_c/from_i get set to c2i/i2i
103
104 if (access_flags.is_native()) {
105 clear_native_function();
106 set_signature_handler(NULL);
107 }
108
109 NOT_PRODUCT(set_compiled_invocation_count(0);)
110 }
111
112 // Release Method*. The nmethod will be gone when we get here because
113 // we've walked the code cache.
114 void Method::deallocate_contents(ClassLoaderData* loader_data) {
115 MetadataFactory::free_metadata(loader_data, constMethod());
116 set_constMethod(NULL);
117 MetadataFactory::free_metadata(loader_data, method_data());
118 set_method_data(NULL);
119 MetadataFactory::free_metadata(loader_data, method_counters());
120 clear_method_counters();
121 // The nmethod will be gone when we get here.
122 if (code() != NULL) _code = NULL;
123 }
124
125 address Method::get_i2c_entry() {
126 assert(adapter() != NULL, "must have");
127 return adapter()->get_i2c_entry();
128 }
129
130 address Method::get_c2i_entry() {
131 assert(adapter() != NULL, "must have");
132 return adapter()->get_c2i_entry();
133 }
134
135 address Method::get_c2i_unverified_entry() {
136 assert(adapter() != NULL, "must have");
137 return adapter()->get_c2i_unverified_entry();
138 }
139
140 char* Method::name_and_sig_as_C_string() const {
141 return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature());
142 }
143
144 char* Method::name_and_sig_as_C_string(char* buf, int size) const {
145 return name_and_sig_as_C_string(constants()->pool_holder(), name(), signature(), buf, size);
146 }
147
148 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature) {
149 const char* klass_name = klass->external_name();
150 int klass_name_len = (int)strlen(klass_name);
151 int method_name_len = method_name->utf8_length();
152 int len = klass_name_len + 1 + method_name_len + signature->utf8_length();
153 char* dest = NEW_RESOURCE_ARRAY(char, len + 1);
154 strcpy(dest, klass_name);
155 dest[klass_name_len] = '.';
156 strcpy(&dest[klass_name_len + 1], method_name->as_C_string());
157 strcpy(&dest[klass_name_len + 1 + method_name_len], signature->as_C_string());
158 dest[len] = 0;
159 return dest;
160 }
161
162 char* Method::name_and_sig_as_C_string(Klass* klass, Symbol* method_name, Symbol* signature, char* buf, int size) {
163 Symbol* klass_name = klass->name();
164 klass_name->as_klass_external_name(buf, size);
165 int len = (int)strlen(buf);
166
167 if (len < size - 1) {
168 buf[len++] = '.';
169
170 method_name->as_C_string(&(buf[len]), size - len);
171 len = (int)strlen(buf);
172
173 signature->as_C_string(&(buf[len]), size - len);
174 }
175
176 return buf;
177 }
178
179 const char* Method::external_name() const {
180 return external_name(constants()->pool_holder(), name(), signature());
181 }
182
183 void Method::print_external_name(outputStream *os) const {
184 print_external_name(os, constants()->pool_holder(), name(), signature());
185 }
186
187 const char* Method::external_name(Klass* klass, Symbol* method_name, Symbol* signature) {
188 stringStream ss;
189 print_external_name(&ss, klass, method_name, signature);
190 return ss.as_string();
191 }
192
193 void Method::print_external_name(outputStream *os, Klass* klass, Symbol* method_name, Symbol* signature) {
194 signature->print_as_signature_external_return_type(os);
195 os->print(" %s.%s(", klass->external_name(), method_name->as_C_string());
196 signature->print_as_signature_external_parameters(os);
197 os->print(")");
198 }
199
200 int Method::fast_exception_handler_bci_for(const methodHandle& mh, Klass* ex_klass, int throw_bci, TRAPS) {
201 // exception table holds quadruple entries of the form (beg_bci, end_bci, handler_bci, klass_index)
202 // access exception table
203 ExceptionTable table(mh());
204 int length = table.length();
205 // iterate through all entries sequentially
206 constantPoolHandle pool(THREAD, mh->constants());
207 for (int i = 0; i < length; i ++) {
208 //reacquire the table in case a GC happened
209 ExceptionTable table(mh());
210 int beg_bci = table.start_pc(i);
211 int end_bci = table.end_pc(i);
212 assert(beg_bci <= end_bci, "inconsistent exception table");
213 if (beg_bci <= throw_bci && throw_bci < end_bci) {
214 // exception handler bci range covers throw_bci => investigate further
215 int handler_bci = table.handler_pc(i);
216 int klass_index = table.catch_type_index(i);
217 if (klass_index == 0) {
218 return handler_bci;
219 } else if (ex_klass == NULL) {
220 return handler_bci;
221 } else {
222 // we know the exception class => get the constraint class
223 // this may require loading of the constraint class; if verification
224 // fails or some other exception occurs, return handler_bci
225 Klass* k = pool->klass_at(klass_index, CHECK_(handler_bci));
226 assert(k != NULL, "klass not loaded");
227 if (ex_klass->is_subtype_of(k)) {
228 return handler_bci;
229 }
230 }
231 }
232 }
233
234 return -1;
235 }
236
237 void Method::mask_for(int bci, InterpreterOopMap* mask) {
238 methodHandle h_this(Thread::current(), this);
239 // Only GC uses the OopMapCache during thread stack root scanning
240 // any other uses generate an oopmap but do not save it in the cache.
241 if (Universe::heap()->is_gc_active()) {
242 method_holder()->mask_for(h_this, bci, mask);
243 } else {
244 OopMapCache::compute_one_oop_map(h_this, bci, mask);
245 }
246 return;
247 }
248
249
250 int Method::bci_from(address bcp) const {
251 if (is_native() && bcp == 0) {
252 return 0;
253 }
254 #ifdef ASSERT
255 {
256 ResourceMark rm;
257 assert(is_native() && bcp == code_base() || contains(bcp) || VMError::is_error_reported(),
258 "bcp doesn't belong to this method: bcp: " INTPTR_FORMAT ", method: %s",
259 p2i(bcp), name_and_sig_as_C_string());
260 }
261 #endif
262 return bcp - code_base();
263 }
264
265
266 int Method::validate_bci(int bci) const {
267 return (bci == 0 || bci < code_size()) ? bci : -1;
268 }
269
270 // Return bci if it appears to be a valid bcp
271 // Return -1 otherwise.
272 // Used by profiling code, when invalid data is a possibility.
273 // The caller is responsible for validating the Method* itself.
274 int Method::validate_bci_from_bcp(address bcp) const {
275 // keep bci as -1 if not a valid bci
276 int bci = -1;
277 if (bcp == 0 || bcp == code_base()) {
278 // code_size() may return 0 and we allow 0 here
279 // the method may be native
280 bci = 0;
281 } else if (contains(bcp)) {
282 bci = bcp - code_base();
283 }
284 // Assert that if we have dodged any asserts, bci is negative.
285 assert(bci == -1 || bci == bci_from(bcp_from(bci)), "sane bci if >=0");
286 return bci;
287 }
288
289 address Method::bcp_from(int bci) const {
290 assert((is_native() && bci == 0) || (!is_native() && 0 <= bci && bci < code_size()),
291 "illegal bci: %d for %s method", bci, is_native() ? "native" : "non-native");
292 address bcp = code_base() + bci;
293 assert(is_native() && bcp == code_base() || contains(bcp), "bcp doesn't belong to this method");
294 return bcp;
295 }
296
297 address Method::bcp_from(address bcp) const {
298 if (is_native() && bcp == NULL) {
299 return code_base();
300 } else {
301 return bcp;
302 }
303 }
304
305 int Method::size(bool is_native) {
306 // If native, then include pointers for native_function and signature_handler
307 int extra_bytes = (is_native) ? 2*sizeof(address*) : 0;
308 int extra_words = align_up(extra_bytes, BytesPerWord) / BytesPerWord;
309 return align_metadata_size(header_size() + extra_words);
310 }
311
312
313 Symbol* Method::klass_name() const {
314 return method_holder()->name();
315 }
316
317
318 void Method::metaspace_pointers_do(MetaspaceClosure* it) {
319 log_trace(cds)("Iter(Method): %p", this);
320
321 it->push(&_constMethod);
322 it->push(&_method_data);
323 it->push(&_method_counters);
324 }
325
326 // Attempt to return method oop to original state. Clear any pointers
327 // (to objects outside the shared spaces). We won't be able to predict
328 // where they should point in a new JVM. Further initialize some
329 // entries now in order allow them to be write protected later.
330
331 void Method::remove_unshareable_info() {
332 unlink_method();
333 }
334
335 void Method::set_vtable_index(int index) {
336 if (is_shared() && !MetaspaceShared::remapped_readwrite()) {
337 // At runtime initialize_vtable is rerun as part of link_class_impl()
338 // for a shared class loaded by the non-boot loader to obtain the loader
339 // constraints based on the runtime classloaders' context.
340 return; // don't write into the shared class
341 } else {
342 _vtable_index = index;
343 }
344 }
345
346 void Method::set_itable_index(int index) {
347 if (is_shared() && !MetaspaceShared::remapped_readwrite()) {
348 // At runtime initialize_itable is rerun as part of link_class_impl()
349 // for a shared class loaded by the non-boot loader to obtain the loader
350 // constraints based on the runtime classloaders' context. The dumptime
351 // itable index should be the same as the runtime index.
352 assert(_vtable_index == itable_index_max - index,
353 "archived itable index is different from runtime index");
354 return; // don’t write into the shared class
355 } else {
356 _vtable_index = itable_index_max - index;
357 }
358 assert(valid_itable_index(), "");
359 }
360
361
362
363 bool Method::was_executed_more_than(int n) {
364 // Invocation counter is reset when the Method* is compiled.
365 // If the method has compiled code we therefore assume it has
366 // be excuted more than n times.
367 if (is_accessor() || is_empty_method() || (code() != NULL)) {
368 // interpreter doesn't bump invocation counter of trivial methods
369 // compiler does not bump invocation counter of compiled methods
370 return true;
371 }
372 else if ((method_counters() != NULL &&
373 method_counters()->invocation_counter()->carry()) ||
374 (method_data() != NULL &&
375 method_data()->invocation_counter()->carry())) {
376 // The carry bit is set when the counter overflows and causes
377 // a compilation to occur. We don't know how many times
378 // the counter has been reset, so we simply assume it has
379 // been executed more than n times.
380 return true;
381 } else {
382 return invocation_count() > n;
383 }
384 }
385
386 void Method::print_invocation_count() {
387 if (is_static()) tty->print("static ");
388 if (is_final()) tty->print("final ");
389 if (is_synchronized()) tty->print("synchronized ");
390 if (is_native()) tty->print("native ");
391 tty->print("%s::", method_holder()->external_name());
392 name()->print_symbol_on(tty);
393 signature()->print_symbol_on(tty);
394
395 if (WizardMode) {
396 // dump the size of the byte codes
397 tty->print(" {%d}", code_size());
398 }
399 tty->cr();
400
401 tty->print_cr (" interpreter_invocation_count: %8d ", interpreter_invocation_count());
402 tty->print_cr (" invocation_counter: %8d ", invocation_count());
403 tty->print_cr (" backedge_counter: %8d ", backedge_count());
404 #ifndef PRODUCT
405 if (CountCompiledCalls) {
406 tty->print_cr (" compiled_invocation_count: %8d ", compiled_invocation_count());
407 }
408 #endif
409 }
410
411 // Build a MethodData* object to hold information about this method
412 // collected in the interpreter.
413 void Method::build_interpreter_method_data(const methodHandle& method, TRAPS) {
414 // Do not profile the method if metaspace has hit an OOM previously
415 // allocating profiling data. Callers clear pending exception so don't
416 // add one here.
417 if (ClassLoaderDataGraph::has_metaspace_oom()) {
418 return;
419 }
420
421 // Grab a lock here to prevent multiple
422 // MethodData*s from being created.
423 MutexLocker ml(MethodData_lock, THREAD);
424 if (method->method_data() == NULL) {
425 ClassLoaderData* loader_data = method->method_holder()->class_loader_data();
426 MethodData* method_data = MethodData::allocate(loader_data, method, THREAD);
427 if (HAS_PENDING_EXCEPTION) {
428 CompileBroker::log_metaspace_failure();
429 ClassLoaderDataGraph::set_metaspace_oom(true);
430 return; // return the exception (which is cleared)
431 }
432
433 method->set_method_data(method_data);
434 if (PrintMethodData && (Verbose || WizardMode)) {
435 ResourceMark rm(THREAD);
436 tty->print("build_interpreter_method_data for ");
437 method->print_name(tty);
438 tty->cr();
439 // At the end of the run, the MDO, full of data, will be dumped.
440 }
441 }
442 }
443
444 MethodCounters* Method::build_method_counters(Method* m, TRAPS) {
445 // Do not profile the method if metaspace has hit an OOM previously
446 if (ClassLoaderDataGraph::has_metaspace_oom()) {
447 return NULL;
448 }
449
450 methodHandle mh(m);
451 MethodCounters* counters = MethodCounters::allocate(mh, THREAD);
452 if (HAS_PENDING_EXCEPTION) {
453 CompileBroker::log_metaspace_failure();
454 ClassLoaderDataGraph::set_metaspace_oom(true);
455 return NULL; // return the exception (which is cleared)
456 }
457 if (!mh->init_method_counters(counters)) {
458 MetadataFactory::free_metadata(mh->method_holder()->class_loader_data(), counters);
459 }
460
461 if (LogTouchedMethods) {
462 mh->log_touched(CHECK_NULL);
463 }
464
465 return mh->method_counters();
466 }
467
468 bool Method::init_method_counters(MethodCounters* counters) {
469 // Try to install a pointer to MethodCounters, return true on success.
470 return Atomic::replace_if_null(counters, &_method_counters);
471 }
472
473 int Method::extra_stack_words() {
474 // not an inline function, to avoid a header dependency on Interpreter
475 return extra_stack_entries() * Interpreter::stackElementSize;
476 }
477
478
479 void Method::compute_size_of_parameters(Thread *thread) {
480 ArgumentSizeComputer asc(signature());
481 set_size_of_parameters(asc.size() + (is_static() ? 0 : 1));
482 }
483
484 BasicType Method::result_type() const {
485 ResultTypeFinder rtf(signature());
486 return rtf.type();
487 }
488
489
490 bool Method::is_empty_method() const {
491 return code_size() == 1
492 && *code_base() == Bytecodes::_return;
493 }
494
495
496 bool Method::is_vanilla_constructor() const {
497 // Returns true if this method is a vanilla constructor, i.e. an "<init>" "()V" method
498 // which only calls the superclass vanilla constructor and possibly does stores of
499 // zero constants to local fields:
500 //
501 // aload_0
502 // invokespecial
503 // indexbyte1
504 // indexbyte2
505 //
506 // followed by an (optional) sequence of:
507 //
508 // aload_0
509 // aconst_null / iconst_0 / fconst_0 / dconst_0
510 // putfield
511 // indexbyte1
512 // indexbyte2
513 //
514 // followed by:
515 //
516 // return
517
518 assert(name() == vmSymbols::object_initializer_name(), "Should only be called for default constructors");
519 assert(signature() == vmSymbols::void_method_signature(), "Should only be called for default constructors");
520 int size = code_size();
521 // Check if size match
522 if (size == 0 || size % 5 != 0) return false;
523 address cb = code_base();
524 int last = size - 1;
525 if (cb[0] != Bytecodes::_aload_0 || cb[1] != Bytecodes::_invokespecial || cb[last] != Bytecodes::_return) {
526 // Does not call superclass default constructor
527 return false;
528 }
529 // Check optional sequence
530 for (int i = 4; i < last; i += 5) {
531 if (cb[i] != Bytecodes::_aload_0) return false;
532 if (!Bytecodes::is_zero_const(Bytecodes::cast(cb[i+1]))) return false;
533 if (cb[i+2] != Bytecodes::_putfield) return false;
534 }
535 return true;
536 }
537
538
539 bool Method::compute_has_loops_flag() {
540 BytecodeStream bcs(this);
541 Bytecodes::Code bc;
542
543 while ((bc = bcs.next()) >= 0) {
544 switch (bc) {
545 case Bytecodes::_ifeq:
546 case Bytecodes::_ifnull:
547 case Bytecodes::_iflt:
548 case Bytecodes::_ifle:
549 case Bytecodes::_ifne:
550 case Bytecodes::_ifnonnull:
551 case Bytecodes::_ifgt:
552 case Bytecodes::_ifge:
553 case Bytecodes::_if_icmpeq:
554 case Bytecodes::_if_icmpne:
555 case Bytecodes::_if_icmplt:
556 case Bytecodes::_if_icmpgt:
557 case Bytecodes::_if_icmple:
558 case Bytecodes::_if_icmpge:
559 case Bytecodes::_if_acmpeq:
560 case Bytecodes::_if_acmpne:
561 case Bytecodes::_goto:
562 case Bytecodes::_jsr:
563 if (bcs.dest() < bcs.next_bci()) _access_flags.set_has_loops();
564 break;
565
566 case Bytecodes::_goto_w:
567 case Bytecodes::_jsr_w:
568 if (bcs.dest_w() < bcs.next_bci()) _access_flags.set_has_loops();
569 break;
570
571 case Bytecodes::_lookupswitch: {
572 Bytecode_lookupswitch lookupswitch(this, bcs.bcp());
573 if (lookupswitch.default_offset() < 0) {
574 _access_flags.set_has_loops();
575 } else {
576 for (int i = 0; i < lookupswitch.number_of_pairs(); ++i) {
577 LookupswitchPair pair = lookupswitch.pair_at(i);
578 if (pair.offset() < 0) {
579 _access_flags.set_has_loops();
580 break;
581 }
582 }
583 }
584 break;
585 }
586 case Bytecodes::_tableswitch: {
587 Bytecode_tableswitch tableswitch(this, bcs.bcp());
588 if (tableswitch.default_offset() < 0) {
589 _access_flags.set_has_loops();
590 } else {
591 for (int i = 0; i < tableswitch.length(); ++i) {
592 if (tableswitch.dest_offset_at(i) < 0) {
593 _access_flags.set_has_loops();
594 }
595 }
596 }
597 break;
598 }
599 default:
600 break;
601 }
602 }
603 _access_flags.set_loops_flag_init();
604 return _access_flags.has_loops();
605 }
606
607 bool Method::is_final_method(AccessFlags class_access_flags) const {
608 // or "does_not_require_vtable_entry"
609 // default method or overpass can occur, is not final (reuses vtable entry)
610 // private methods in classes get vtable entries for backward class compatibility.
611 if (is_overpass() || is_default_method()) return false;
612 return is_final() || class_access_flags.is_final();
613 }
614
615 bool Method::is_final_method() const {
616 return is_final_method(method_holder()->access_flags());
617 }
618
619 bool Method::is_default_method() const {
620 if (method_holder() != NULL &&
621 method_holder()->is_interface() &&
622 !is_abstract() && !is_private()) {
623 return true;
624 } else {
625 return false;
626 }
627 }
628
629 bool Method::can_be_statically_bound(AccessFlags class_access_flags) const {
630 if (is_final_method(class_access_flags)) return true;
631 #ifdef ASSERT
632 ResourceMark rm;
633 bool is_nonv = (vtable_index() == nonvirtual_vtable_index);
634 if (class_access_flags.is_interface()) {
635 assert(is_nonv == is_static() || is_nonv == is_private(),
636 "nonvirtual unexpected for non-static, non-private: %s",
637 name_and_sig_as_C_string());
638 }
639 #endif
640 assert(valid_vtable_index() || valid_itable_index(), "method must be linked before we ask this question");
641 return vtable_index() == nonvirtual_vtable_index;
642 }
643
644 bool Method::can_be_statically_bound() const {
645 return can_be_statically_bound(method_holder()->access_flags());
646 }
647
648 bool Method::is_accessor() const {
649 return is_getter() || is_setter();
650 }
651
652 bool Method::is_getter() const {
653 if (code_size() != 5) return false;
654 if (size_of_parameters() != 1) return false;
655 if (java_code_at(0) != Bytecodes::_aload_0) return false;
656 if (java_code_at(1) != Bytecodes::_getfield) return false;
657 switch (java_code_at(4)) {
658 case Bytecodes::_ireturn:
659 case Bytecodes::_lreturn:
660 case Bytecodes::_freturn:
661 case Bytecodes::_dreturn:
662 case Bytecodes::_areturn:
663 break;
664 default:
665 return false;
666 }
667 return true;
668 }
669
670 bool Method::is_setter() const {
671 if (code_size() != 6) return false;
672 if (java_code_at(0) != Bytecodes::_aload_0) return false;
673 switch (java_code_at(1)) {
674 case Bytecodes::_iload_1:
675 case Bytecodes::_aload_1:
676 case Bytecodes::_fload_1:
677 if (size_of_parameters() != 2) return false;
678 break;
679 case Bytecodes::_dload_1:
680 case Bytecodes::_lload_1:
681 if (size_of_parameters() != 3) return false;
682 break;
683 default:
684 return false;
685 }
686 if (java_code_at(2) != Bytecodes::_putfield) return false;
687 if (java_code_at(5) != Bytecodes::_return) return false;
688 return true;
689 }
690
691 bool Method::is_constant_getter() const {
692 int last_index = code_size() - 1;
693 // Check if the first 1-3 bytecodes are a constant push
694 // and the last bytecode is a return.
695 return (2 <= code_size() && code_size() <= 4 &&
696 Bytecodes::is_const(java_code_at(0)) &&
697 Bytecodes::length_for(java_code_at(0)) == last_index &&
698 Bytecodes::is_return(java_code_at(last_index)));
699 }
700
701 bool Method::is_initializer() const {
702 return is_object_initializer() || is_static_initializer();
703 }
704
705 bool Method::has_valid_initializer_flags() const {
706 return (is_static() ||
707 method_holder()->major_version() < 51);
708 }
709
710 bool Method::is_static_initializer() const {
711 // For classfiles version 51 or greater, ensure that the clinit method is
712 // static. Non-static methods with the name "<clinit>" are not static
713 // initializers. (older classfiles exempted for backward compatibility)
714 return name() == vmSymbols::class_initializer_name() &&
715 has_valid_initializer_flags();
716 }
717
718 bool Method::is_object_initializer() const {
719 return name() == vmSymbols::object_initializer_name();
720 }
721
722 objArrayHandle Method::resolved_checked_exceptions_impl(Method* method, TRAPS) {
723 int length = method->checked_exceptions_length();
724 if (length == 0) { // common case
725 return objArrayHandle(THREAD, Universe::the_empty_class_klass_array());
726 } else {
727 methodHandle h_this(THREAD, method);
728 objArrayOop m_oop = oopFactory::new_objArray(SystemDictionary::Class_klass(), length, CHECK_(objArrayHandle()));
729 objArrayHandle mirrors (THREAD, m_oop);
730 for (int i = 0; i < length; i++) {
731 CheckedExceptionElement* table = h_this->checked_exceptions_start(); // recompute on each iteration, not gc safe
732 Klass* k = h_this->constants()->klass_at(table[i].class_cp_index, CHECK_(objArrayHandle()));
733 if (log_is_enabled(Warning, exceptions) &&
734 !k->is_subclass_of(SystemDictionary::Throwable_klass())) {
735 ResourceMark rm(THREAD);
736 log_warning(exceptions)(
737 "Class %s in throws clause of method %s is not a subtype of class java.lang.Throwable",
738 k->external_name(), method->external_name());
739 }
740 mirrors->obj_at_put(i, k->java_mirror());
741 }
742 return mirrors;
743 }
744 };
745
746
747 int Method::line_number_from_bci(int bci) const {
748 int best_bci = 0;
749 int best_line = -1;
750 if (bci == SynchronizationEntryBCI) bci = 0;
751 if (0 <= bci && bci < code_size() && has_linenumber_table()) {
752 // The line numbers are a short array of 2-tuples [start_pc, line_number].
753 // Not necessarily sorted and not necessarily one-to-one.
754 CompressedLineNumberReadStream stream(compressed_linenumber_table());
755 while (stream.read_pair()) {
756 if (stream.bci() == bci) {
757 // perfect match
758 return stream.line();
759 } else {
760 // update best_bci/line
761 if (stream.bci() < bci && stream.bci() >= best_bci) {
762 best_bci = stream.bci();
763 best_line = stream.line();
764 }
765 }
766 }
767 }
768 return best_line;
769 }
770
771
772 bool Method::is_klass_loaded_by_klass_index(int klass_index) const {
773 if( constants()->tag_at(klass_index).is_unresolved_klass() ) {
774 Thread *thread = Thread::current();
775 Symbol* klass_name = constants()->klass_name_at(klass_index);
776 Handle loader(thread, method_holder()->class_loader());
777 Handle prot (thread, method_holder()->protection_domain());
778 return SystemDictionary::find(klass_name, loader, prot, thread) != NULL;
779 } else {
780 return true;
781 }
782 }
783
784
785 bool Method::is_klass_loaded(int refinfo_index, bool must_be_resolved) const {
786 int klass_index = constants()->klass_ref_index_at(refinfo_index);
787 if (must_be_resolved) {
788 // Make sure klass is resolved in constantpool.
789 if (constants()->tag_at(klass_index).is_unresolved_klass()) return false;
790 }
791 return is_klass_loaded_by_klass_index(klass_index);
792 }
793
794
795 void Method::set_native_function(address function, bool post_event_flag) {
796 assert(function != NULL, "use clear_native_function to unregister natives");
797 assert(!is_method_handle_intrinsic() || function == SharedRuntime::native_method_throw_unsatisfied_link_error_entry(), "");
798 address* native_function = native_function_addr();
799
800 // We can see racers trying to place the same native function into place. Once
801 // is plenty.
802 address current = *native_function;
803 if (current == function) return;
804 if (post_event_flag && JvmtiExport::should_post_native_method_bind() &&
805 function != NULL) {
806 // native_method_throw_unsatisfied_link_error_entry() should only
807 // be passed when post_event_flag is false.
808 assert(function !=
809 SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
810 "post_event_flag mis-match");
811
812 // post the bind event, and possible change the bind function
813 JvmtiExport::post_native_method_bind(this, &function);
814 }
815 *native_function = function;
816 // This function can be called more than once. We must make sure that we always
817 // use the latest registered method -> check if a stub already has been generated.
818 // If so, we have to make it not_entrant.
819 CompiledMethod* nm = code(); // Put it into local variable to guard against concurrent updates
820 if (nm != NULL) {
821 nm->make_not_entrant();
822 }
823 }
824
825
826 bool Method::has_native_function() const {
827 if (is_method_handle_intrinsic())
828 return false; // special-cased in SharedRuntime::generate_native_wrapper
829 address func = native_function();
830 return (func != NULL && func != SharedRuntime::native_method_throw_unsatisfied_link_error_entry());
831 }
832
833
834 void Method::clear_native_function() {
835 // Note: is_method_handle_intrinsic() is allowed here.
836 set_native_function(
837 SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
838 !native_bind_event_is_interesting);
839 clear_code();
840 }
841
842
843 void Method::set_signature_handler(address handler) {
844 address* signature_handler = signature_handler_addr();
845 *signature_handler = handler;
846 }
847
848
849 void Method::print_made_not_compilable(int comp_level, bool is_osr, bool report, const char* reason) {
850 if (PrintCompilation && report) {
851 ttyLocker ttyl;
852 tty->print("made not %scompilable on ", is_osr ? "OSR " : "");
853 if (comp_level == CompLevel_all) {
854 tty->print("all levels ");
855 } else {
856 tty->print("level %d ", comp_level);
857 }
858 this->print_short_name(tty);
859 int size = this->code_size();
860 if (size > 0) {
861 tty->print(" (%d bytes)", size);
862 }
863 if (reason != NULL) {
864 tty->print(" %s", reason);
865 }
866 tty->cr();
867 }
868 if ((TraceDeoptimization || LogCompilation) && (xtty != NULL)) {
869 ttyLocker ttyl;
870 xtty->begin_elem("make_not_compilable thread='" UINTX_FORMAT "' osr='%d' level='%d'",
871 os::current_thread_id(), is_osr, comp_level);
872 if (reason != NULL) {
873 xtty->print(" reason=\'%s\'", reason);
874 }
875 xtty->method(this);
876 xtty->stamp();
877 xtty->end_elem();
878 }
879 }
880
881 bool Method::is_always_compilable() const {
882 // Generated adapters must be compiled
883 if (is_method_handle_intrinsic() && is_synthetic()) {
884 assert(!is_not_c1_compilable(), "sanity check");
885 assert(!is_not_c2_compilable(), "sanity check");
886 return true;
887 }
888
889 return false;
890 }
891
892 bool Method::is_not_compilable(int comp_level) const {
893 if (number_of_breakpoints() > 0)
894 return true;
895 if (is_always_compilable())
896 return false;
897 if (comp_level == CompLevel_any)
898 return is_not_c1_compilable() || is_not_c2_compilable();
899 if (is_c1_compile(comp_level))
900 return is_not_c1_compilable();
901 if (is_c2_compile(comp_level))
902 return is_not_c2_compilable();
903 return false;
904 }
905
906 // call this when compiler finds that this method is not compilable
907 void Method::set_not_compilable(int comp_level, bool report, const char* reason) {
908 if (is_always_compilable()) {
909 // Don't mark a method which should be always compilable
910 return;
911 }
912 print_made_not_compilable(comp_level, /*is_osr*/ false, report, reason);
913 if (comp_level == CompLevel_all) {
914 set_not_c1_compilable();
915 set_not_c2_compilable();
916 } else {
917 if (is_c1_compile(comp_level))
918 set_not_c1_compilable();
919 if (is_c2_compile(comp_level))
920 set_not_c2_compilable();
921 }
922 CompilationPolicy::policy()->disable_compilation(this);
923 assert(!CompilationPolicy::can_be_compiled(this, comp_level), "sanity check");
924 }
925
926 bool Method::is_not_osr_compilable(int comp_level) const {
927 if (is_not_compilable(comp_level))
928 return true;
929 if (comp_level == CompLevel_any)
930 return is_not_c1_osr_compilable() || is_not_c2_osr_compilable();
931 if (is_c1_compile(comp_level))
932 return is_not_c1_osr_compilable();
933 if (is_c2_compile(comp_level))
934 return is_not_c2_osr_compilable();
935 return false;
936 }
937
938 void Method::set_not_osr_compilable(int comp_level, bool report, const char* reason) {
939 print_made_not_compilable(comp_level, /*is_osr*/ true, report, reason);
940 if (comp_level == CompLevel_all) {
941 set_not_c1_osr_compilable();
942 set_not_c2_osr_compilable();
943 } else {
944 if (is_c1_compile(comp_level))
945 set_not_c1_osr_compilable();
946 if (is_c2_compile(comp_level))
947 set_not_c2_osr_compilable();
948 }
949 CompilationPolicy::policy()->disable_compilation(this);
950 assert(!CompilationPolicy::can_be_osr_compiled(this, comp_level), "sanity check");
951 }
952
953 // Revert to using the interpreter and clear out the nmethod
954 void Method::clear_code(bool acquire_lock /* = true */) {
955 MutexLockerEx pl(acquire_lock ? Patching_lock : NULL, Mutex::_no_safepoint_check_flag);
956 // this may be NULL if c2i adapters have not been made yet
957 // Only should happen at allocate time.
958 if (adapter() == NULL) {
959 _from_compiled_entry = NULL;
960 } else {
961 _from_compiled_entry = adapter()->get_c2i_entry();
962 }
963 OrderAccess::storestore();
964 _from_interpreted_entry = _i2i_entry;
965 OrderAccess::storestore();
966 _code = NULL;
967 }
968
969 #if INCLUDE_CDS
970 // Called by class data sharing to remove any entry points (which are not shared)
971 void Method::unlink_method() {
972 _code = NULL;
973
974 assert(DumpSharedSpaces, "dump time only");
975 // Set the values to what they should be at run time. Note that
976 // this Method can no longer be executed during dump time.
977 _i2i_entry = Interpreter::entry_for_cds_method(this);
978 _from_interpreted_entry = _i2i_entry;
979
980 if (is_native()) {
981 *native_function_addr() = NULL;
982 set_signature_handler(NULL);
983 }
984 NOT_PRODUCT(set_compiled_invocation_count(0);)
985
986 CDSAdapterHandlerEntry* cds_adapter = (CDSAdapterHandlerEntry*)adapter();
987 constMethod()->set_adapter_trampoline(cds_adapter->get_adapter_trampoline());
988 _from_compiled_entry = cds_adapter->get_c2i_entry_trampoline();
989 assert(*((int*)_from_compiled_entry) == 0, "must be NULL during dump time, to be initialized at run time");
990
991 set_method_data(NULL);
992 clear_method_counters();
993 }
994 #endif
995
996 /****************************************************************************
997 // The following illustrates how the entries work for CDS shared Methods:
998 //
999 // Our goal is to delay writing into a shared Method until it's compiled.
1000 // Hence, we want to determine the initial values for _i2i_entry,
1001 // _from_interpreted_entry and _from_compiled_entry during CDS dump time.
1002 //
1003 // In this example, both Methods A and B have the _i2i_entry of "zero_locals".
1004 // They also have similar signatures so that they will share the same
1005 // AdapterHandlerEntry.
1006 //
1007 // _adapter_trampoline points to a fixed location in the RW section of
1008 // the CDS archive. This location initially contains a NULL pointer. When the
1009 // first of method A or B is linked, an AdapterHandlerEntry is allocated
1010 // dynamically, and its c2i/i2c entries are generated.
1011 //
1012 // _i2i_entry and _from_interpreted_entry initially points to the same
1013 // (fixed) location in the CODE section of the CDS archive. This contains
1014 // an unconditional branch to the actual entry for "zero_locals", which is
1015 // generated at run time and may be on an arbitrary address. Thus, the
1016 // unconditional branch is also generated at run time to jump to the correct
1017 // address.
1018 //
1019 // Similarly, _from_compiled_entry points to a fixed address in the CODE
1020 // section. This address has enough space for an unconditional branch
1021 // instruction, and is initially zero-filled. After the AdapterHandlerEntry is
1022 // initialized, and the address for the actual c2i_entry is known, we emit a
1023 // branch instruction here to branch to the actual c2i_entry.
1024 //
1025 // The effect of the extra branch on the i2i and c2i entries is negligible.
1026 //
1027 // The reason for putting _adapter_trampoline in RO is many shared Methods
1028 // share the same AdapterHandlerEntry, so we can save space in the RW section
1029 // by having the extra indirection.
1030
1031
1032 [Method A: RW]
1033 _constMethod ----> [ConstMethod: RO]
1034 _adapter_trampoline -----------+
1035 |
1036 _i2i_entry (same value as method B) |
1037 _from_interpreted_entry (same value as method B) |
1038 _from_compiled_entry (same value as method B) |
1039 |
1040 |
1041 [Method B: RW] +--------+
1042 _constMethod ----> [ConstMethod: RO] |
1043 _adapter_trampoline --+--->(AdapterHandlerEntry* ptr: RW)-+
1044 |
1045 +-------------------------------+
1046 |
1047 +----> [AdapterHandlerEntry] (allocated at run time)
1048 _fingerprint
1049 _c2i_entry ---------------------------------+->[c2i entry..]
1050 _i2i_entry -------------+ _i2c_entry ---------------+-> [i2c entry..] |
1051 _from_interpreted_entry | _c2i_unverified_entry | |
1052 | | | |
1053 | | (_cds_entry_table: CODE) | |
1054 | +->[0]: jmp _entry_table[0] --> (i2i_entry_for "zero_locals") | |
1055 | | (allocated at run time) | |
1056 | | ... [asm code ...] | |
1057 +-[not compiled]-+ [n]: jmp _entry_table[n] | |
1058 | | |
1059 | | |
1060 +-[compiled]-------------------------------------------------------------------+ |
1061 |
1062 _from_compiled_entry------------> (_c2i_entry_trampoline: CODE) |
1063 [jmp c2i_entry] ------------------------------------------------------+
1064
1065 ***/
1066
1067 // Called when the method_holder is getting linked. Setup entrypoints so the method
1068 // is ready to be called from interpreter, compiler, and vtables.
1069 void Method::link_method(const methodHandle& h_method, TRAPS) {
1070 // If the code cache is full, we may reenter this function for the
1071 // leftover methods that weren't linked.
1072 if (is_shared()) {
1073 address entry = Interpreter::entry_for_cds_method(h_method);
1074 assert(entry != NULL && entry == _i2i_entry,
1075 "should be correctly set during dump time");
1076 if (adapter() != NULL) {
1077 return;
1078 }
1079 assert(entry == _from_interpreted_entry,
1080 "should be correctly set during dump time");
1081 } else if (_i2i_entry != NULL) {
1082 return;
1083 }
1084 assert( _code == NULL, "nothing compiled yet" );
1085
1086 // Setup interpreter entrypoint
1087 assert(this == h_method(), "wrong h_method()" );
1088
1089 if (!is_shared()) {
1090 assert(adapter() == NULL, "init'd to NULL");
1091 address entry = Interpreter::entry_for_method(h_method);
1092 assert(entry != NULL, "interpreter entry must be non-null");
1093 // Sets both _i2i_entry and _from_interpreted_entry
1094 set_interpreter_entry(entry);
1095 }
1096
1097 // Don't overwrite already registered native entries.
1098 if (is_native() && !has_native_function()) {
1099 set_native_function(
1100 SharedRuntime::native_method_throw_unsatisfied_link_error_entry(),
1101 !native_bind_event_is_interesting);
1102 }
1103
1104 // Setup compiler entrypoint. This is made eagerly, so we do not need
1105 // special handling of vtables. An alternative is to make adapters more
1106 // lazily by calling make_adapter() from from_compiled_entry() for the
1107 // normal calls. For vtable calls life gets more complicated. When a
1108 // call-site goes mega-morphic we need adapters in all methods which can be
1109 // called from the vtable. We need adapters on such methods that get loaded
1110 // later. Ditto for mega-morphic itable calls. If this proves to be a
1111 // problem we'll make these lazily later.
1112 (void) make_adapters(h_method, CHECK);
1113
1114 // ONLY USE the h_method now as make_adapter may have blocked
1115
1116 }
1117
1118 address Method::make_adapters(const methodHandle& mh, TRAPS) {
1119 // Adapters for compiled code are made eagerly here. They are fairly
1120 // small (generally < 100 bytes) and quick to make (and cached and shared)
1121 // so making them eagerly shouldn't be too expensive.
1122 AdapterHandlerEntry* adapter = AdapterHandlerLibrary::get_adapter(mh);
1123 if (adapter == NULL ) {
1124 if (!is_init_completed()) {
1125 // Don't throw exceptions during VM initialization because java.lang.* classes
1126 // might not have been initialized, causing problems when constructing the
1127 // Java exception object.
1128 vm_exit_during_initialization("Out of space in CodeCache for adapters");
1129 } else {
1130 THROW_MSG_NULL(vmSymbols::java_lang_VirtualMachineError(), "Out of space in CodeCache for adapters");
1131 }
1132 }
1133
1134 if (mh->is_shared()) {
1135 assert(mh->adapter() == adapter, "must be");
1136 assert(mh->_from_compiled_entry != NULL, "must be");
1137 } else {
1138 mh->set_adapter_entry(adapter);
1139 mh->_from_compiled_entry = adapter->get_c2i_entry();
1140 }
1141 return adapter->get_c2i_entry();
1142 }
1143
1144 void Method::restore_unshareable_info(TRAPS) {
1145 assert(is_method() && is_valid_method(), "ensure C++ vtable is restored");
1146
1147 // Since restore_unshareable_info can be called more than once for a method, don't
1148 // redo any work.
1149 if (adapter() == NULL) {
1150 methodHandle mh(THREAD, this);
1151 link_method(mh, CHECK);
1152 }
1153 }
1154
1155 address Method::from_compiled_entry_no_trampoline() const {
1156 CompiledMethod *code = OrderAccess::load_acquire(&_code);
1157 if (code) {
1158 return code->verified_entry_point();
1159 } else {
1160 return adapter()->get_c2i_entry();
1161 }
1162 }
1163
1164 // The verified_code_entry() must be called when a invoke is resolved
1165 // on this method.
1166
1167 // It returns the compiled code entry point, after asserting not null.
1168 // This function is called after potential safepoints so that nmethod
1169 // or adapter that it points to is still live and valid.
1170 // This function must not hit a safepoint!
1171 address Method::verified_code_entry() {
1172 debug_only(NoSafepointVerifier nsv;)
1173 assert(_from_compiled_entry != NULL, "must be set");
1174 return _from_compiled_entry;
1175 }
1176
1177 // Check that if an nmethod ref exists, it has a backlink to this or no backlink at all
1178 // (could be racing a deopt).
1179 // Not inline to avoid circular ref.
1180 bool Method::check_code() const {
1181 // cached in a register or local. There's a race on the value of the field.
1182 CompiledMethod *code = OrderAccess::load_acquire(&_code);
1183 return code == NULL || (code->method() == NULL) || (code->method() == (Method*)this && !code->is_osr_method());
1184 }
1185
1186 // Install compiled code. Instantly it can execute.
1187 void Method::set_code(const methodHandle& mh, CompiledMethod *code) {
1188 MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
1189 assert( code, "use clear_code to remove code" );
1190 assert( mh->check_code(), "" );
1191
1192 guarantee(mh->adapter() != NULL, "Adapter blob must already exist!");
1193
1194 // These writes must happen in this order, because the interpreter will
1195 // directly jump to from_interpreted_entry which jumps to an i2c adapter
1196 // which jumps to _from_compiled_entry.
1197 mh->_code = code; // Assign before allowing compiled code to exec
1198
1199 int comp_level = code->comp_level();
1200 // In theory there could be a race here. In practice it is unlikely
1201 // and not worth worrying about.
1202 if (comp_level > mh->highest_comp_level()) {
1203 mh->set_highest_comp_level(comp_level);
1204 }
1205
1206 OrderAccess::storestore();
1207 mh->_from_compiled_entry = code->verified_entry_point();
1208 OrderAccess::storestore();
1209 // Instantly compiled code can execute.
1210 if (!mh->is_method_handle_intrinsic())
1211 mh->_from_interpreted_entry = mh->get_i2c_entry();
1212 }
1213
1214
1215 bool Method::is_overridden_in(Klass* k) const {
1216 InstanceKlass* ik = InstanceKlass::cast(k);
1217
1218 if (ik->is_interface()) return false;
1219
1220 // If method is an interface, we skip it - except if it
1221 // is a miranda method
1222 if (method_holder()->is_interface()) {
1223 // Check that method is not a miranda method
1224 if (ik->lookup_method(name(), signature()) == NULL) {
1225 // No implementation exist - so miranda method
1226 return false;
1227 }
1228 return true;
1229 }
1230
1231 assert(ik->is_subclass_of(method_holder()), "should be subklass");
1232 if (!has_vtable_index()) {
1233 return false;
1234 } else {
1235 Method* vt_m = ik->method_at_vtable(vtable_index());
1236 return vt_m != this;
1237 }
1238 }
1239
1240
1241 // give advice about whether this Method* should be cached or not
1242 bool Method::should_not_be_cached() const {
1243 if (is_old()) {
1244 // This method has been redefined. It is either EMCP or obsolete
1245 // and we don't want to cache it because that would pin the method
1246 // down and prevent it from being collectible if and when it
1247 // finishes executing.
1248 return true;
1249 }
1250
1251 // caching this method should be just fine
1252 return false;
1253 }
1254
1255
1256 /**
1257 * Returns true if this is one of the specially treated methods for
1258 * security related stack walks (like Reflection.getCallerClass).
1259 */
1260 bool Method::is_ignored_by_security_stack_walk() const {
1261 if (intrinsic_id() == vmIntrinsics::_invoke) {
1262 // This is Method.invoke() -- ignore it
1263 return true;
1264 }
1265 if (method_holder()->is_subclass_of(SystemDictionary::reflect_MethodAccessorImpl_klass())) {
1266 // This is an auxilary frame -- ignore it
1267 return true;
1268 }
1269 if (is_method_handle_intrinsic() || is_compiled_lambda_form()) {
1270 // This is an internal adapter frame for method handles -- ignore it
1271 return true;
1272 }
1273 return false;
1274 }
1275
1276
1277 // Constant pool structure for invoke methods:
1278 enum {
1279 _imcp_invoke_name = 1, // utf8: 'invokeExact', etc.
1280 _imcp_invoke_signature, // utf8: (variable Symbol*)
1281 _imcp_limit
1282 };
1283
1284 // Test if this method is an MH adapter frame generated by Java code.
1285 // Cf. java/lang/invoke/InvokerBytecodeGenerator
1286 bool Method::is_compiled_lambda_form() const {
1287 return intrinsic_id() == vmIntrinsics::_compiledLambdaForm;
1288 }
1289
1290 // Test if this method is an internal MH primitive method.
1291 bool Method::is_method_handle_intrinsic() const {
1292 vmIntrinsics::ID iid = intrinsic_id();
1293 return (MethodHandles::is_signature_polymorphic(iid) &&
1294 MethodHandles::is_signature_polymorphic_intrinsic(iid));
1295 }
1296
1297 bool Method::has_member_arg() const {
1298 vmIntrinsics::ID iid = intrinsic_id();
1299 return (MethodHandles::is_signature_polymorphic(iid) &&
1300 MethodHandles::has_member_arg(iid));
1301 }
1302
1303 // Make an instance of a signature-polymorphic internal MH primitive.
1304 methodHandle Method::make_method_handle_intrinsic(vmIntrinsics::ID iid,
1305 Symbol* signature,
1306 TRAPS) {
1307 ResourceMark rm;
1308 methodHandle empty;
1309
1310 InstanceKlass* holder = SystemDictionary::MethodHandle_klass();
1311 Symbol* name = MethodHandles::signature_polymorphic_intrinsic_name(iid);
1312 assert(iid == MethodHandles::signature_polymorphic_name_id(name), "");
1313 if (TraceMethodHandles) {
1314 tty->print_cr("make_method_handle_intrinsic MH.%s%s", name->as_C_string(), signature->as_C_string());
1315 }
1316
1317 // invariant: cp->symbol_at_put is preceded by a refcount increment (more usually a lookup)
1318 name->increment_refcount();
1319 signature->increment_refcount();
1320
1321 int cp_length = _imcp_limit;
1322 ClassLoaderData* loader_data = holder->class_loader_data();
1323 constantPoolHandle cp;
1324 {
1325 ConstantPool* cp_oop = ConstantPool::allocate(loader_data, cp_length, CHECK_(empty));
1326 cp = constantPoolHandle(THREAD, cp_oop);
1327 }
1328 cp->set_pool_holder(holder);
1329 cp->symbol_at_put(_imcp_invoke_name, name);
1330 cp->symbol_at_put(_imcp_invoke_signature, signature);
1331 cp->set_has_preresolution();
1332
1333 // decide on access bits: public or not?
1334 int flags_bits = (JVM_ACC_NATIVE | JVM_ACC_SYNTHETIC | JVM_ACC_FINAL);
1335 bool must_be_static = MethodHandles::is_signature_polymorphic_static(iid);
1336 if (must_be_static) flags_bits |= JVM_ACC_STATIC;
1337 assert((flags_bits & JVM_ACC_PUBLIC) == 0, "do not expose these methods");
1338
1339 methodHandle m;
1340 {
1341 InlineTableSizes sizes;
1342 Method* m_oop = Method::allocate(loader_data, 0,
1343 accessFlags_from(flags_bits), &sizes,
1344 ConstMethod::NORMAL, CHECK_(empty));
1345 m = methodHandle(THREAD, m_oop);
1346 }
1347 m->set_constants(cp());
1348 m->set_name_index(_imcp_invoke_name);
1349 m->set_signature_index(_imcp_invoke_signature);
1350 assert(MethodHandles::is_signature_polymorphic_name(m->name()), "");
1351 assert(m->signature() == signature, "");
1352 ResultTypeFinder rtf(signature);
1353 m->constMethod()->set_result_type(rtf.type());
1354 m->compute_size_of_parameters(THREAD);
1355 m->init_intrinsic_id();
1356 assert(m->is_method_handle_intrinsic(), "");
1357 #ifdef ASSERT
1358 if (!MethodHandles::is_signature_polymorphic(m->intrinsic_id())) m->print();
1359 assert(MethodHandles::is_signature_polymorphic(m->intrinsic_id()), "must be an invoker");
1360 assert(m->intrinsic_id() == iid, "correctly predicted iid");
1361 #endif //ASSERT
1362
1363 // Finally, set up its entry points.
1364 assert(m->can_be_statically_bound(), "");
1365 m->set_vtable_index(Method::nonvirtual_vtable_index);
1366 m->link_method(m, CHECK_(empty));
1367
1368 if (TraceMethodHandles && (Verbose || WizardMode)) {
1369 ttyLocker ttyl;
1370 m->print_on(tty);
1371 }
1372
1373 return m;
1374 }
1375
1376 Klass* Method::check_non_bcp_klass(Klass* klass) {
1377 if (klass != NULL && klass->class_loader() != NULL) {
1378 if (klass->is_objArray_klass())
1379 klass = ObjArrayKlass::cast(klass)->bottom_klass();
1380 return klass;
1381 }
1382 return NULL;
1383 }
1384
1385
1386 methodHandle Method::clone_with_new_data(const methodHandle& m, u_char* new_code, int new_code_length,
1387 u_char* new_compressed_linenumber_table, int new_compressed_linenumber_size, TRAPS) {
1388 // Code below does not work for native methods - they should never get rewritten anyway
1389 assert(!m->is_native(), "cannot rewrite native methods");
1390 // Allocate new Method*
1391 AccessFlags flags = m->access_flags();
1392
1393 ConstMethod* cm = m->constMethod();
1394 int checked_exceptions_len = cm->checked_exceptions_length();
1395 int localvariable_len = cm->localvariable_table_length();
1396 int exception_table_len = cm->exception_table_length();
1397 int method_parameters_len = cm->method_parameters_length();
1398 int method_annotations_len = cm->method_annotations_length();
1399 int parameter_annotations_len = cm->parameter_annotations_length();
1400 int type_annotations_len = cm->type_annotations_length();
1401 int default_annotations_len = cm->default_annotations_length();
1402
1403 InlineTableSizes sizes(
1404 localvariable_len,
1405 new_compressed_linenumber_size,
1406 exception_table_len,
1407 checked_exceptions_len,
1408 method_parameters_len,
1409 cm->generic_signature_index(),
1410 method_annotations_len,
1411 parameter_annotations_len,
1412 type_annotations_len,
1413 default_annotations_len,
1414 0);
1415
1416 ClassLoaderData* loader_data = m->method_holder()->class_loader_data();
1417 Method* newm_oop = Method::allocate(loader_data,
1418 new_code_length,
1419 flags,
1420 &sizes,
1421 m->method_type(),
1422 CHECK_(methodHandle()));
1423 methodHandle newm (THREAD, newm_oop);
1424
1425 // Create a shallow copy of Method part, but be careful to preserve the new ConstMethod*
1426 ConstMethod* newcm = newm->constMethod();
1427 int new_const_method_size = newm->constMethod()->size();
1428
1429 // This works because the source and target are both Methods. Some compilers
1430 // (e.g., clang) complain that the target vtable pointer will be stomped,
1431 // so cast away newm()'s and m()'s Methodness.
1432 memcpy((void*)newm(), (void*)m(), sizeof(Method));
1433
1434 // Create shallow copy of ConstMethod.
1435 memcpy(newcm, m->constMethod(), sizeof(ConstMethod));
1436
1437 // Reset correct method/const method, method size, and parameter info
1438 newm->set_constMethod(newcm);
1439 newm->constMethod()->set_code_size(new_code_length);
1440 newm->constMethod()->set_constMethod_size(new_const_method_size);
1441 assert(newm->code_size() == new_code_length, "check");
1442 assert(newm->method_parameters_length() == method_parameters_len, "check");
1443 assert(newm->checked_exceptions_length() == checked_exceptions_len, "check");
1444 assert(newm->exception_table_length() == exception_table_len, "check");
1445 assert(newm->localvariable_table_length() == localvariable_len, "check");
1446 // Copy new byte codes
1447 memcpy(newm->code_base(), new_code, new_code_length);
1448 // Copy line number table
1449 if (new_compressed_linenumber_size > 0) {
1450 memcpy(newm->compressed_linenumber_table(),
1451 new_compressed_linenumber_table,
1452 new_compressed_linenumber_size);
1453 }
1454 // Copy method_parameters
1455 if (method_parameters_len > 0) {
1456 memcpy(newm->method_parameters_start(),
1457 m->method_parameters_start(),
1458 method_parameters_len * sizeof(MethodParametersElement));
1459 }
1460 // Copy checked_exceptions
1461 if (checked_exceptions_len > 0) {
1462 memcpy(newm->checked_exceptions_start(),
1463 m->checked_exceptions_start(),
1464 checked_exceptions_len * sizeof(CheckedExceptionElement));
1465 }
1466 // Copy exception table
1467 if (exception_table_len > 0) {
1468 memcpy(newm->exception_table_start(),
1469 m->exception_table_start(),
1470 exception_table_len * sizeof(ExceptionTableElement));
1471 }
1472 // Copy local variable number table
1473 if (localvariable_len > 0) {
1474 memcpy(newm->localvariable_table_start(),
1475 m->localvariable_table_start(),
1476 localvariable_len * sizeof(LocalVariableTableElement));
1477 }
1478 // Copy stackmap table
1479 if (m->has_stackmap_table()) {
1480 int code_attribute_length = m->stackmap_data()->length();
1481 Array<u1>* stackmap_data =
1482 MetadataFactory::new_array<u1>(loader_data, code_attribute_length, 0, CHECK_NULL);
1483 memcpy((void*)stackmap_data->adr_at(0),
1484 (void*)m->stackmap_data()->adr_at(0), code_attribute_length);
1485 newm->set_stackmap_data(stackmap_data);
1486 }
1487
1488 // copy annotations over to new method
1489 newcm->copy_annotations_from(loader_data, cm, CHECK_NULL);
1490 return newm;
1491 }
1492
1493 vmSymbols::SID Method::klass_id_for_intrinsics(const Klass* holder) {
1494 // if loader is not the default loader (i.e., != NULL), we can't know the intrinsics
1495 // because we are not loading from core libraries
1496 // exception: the AES intrinsics come from lib/ext/sunjce_provider.jar
1497 // which does not use the class default class loader so we check for its loader here
1498 const InstanceKlass* ik = InstanceKlass::cast(holder);
1499 if ((ik->class_loader() != NULL) && !SystemDictionary::is_platform_class_loader(ik->class_loader())) {
1500 return vmSymbols::NO_SID; // regardless of name, no intrinsics here
1501 }
1502
1503 // see if the klass name is well-known:
1504 Symbol* klass_name = ik->name();
1505 return vmSymbols::find_sid(klass_name);
1506 }
1507
1508 void Method::init_intrinsic_id() {
1509 assert(_intrinsic_id == vmIntrinsics::_none, "do this just once");
1510 const uintptr_t max_id_uint = right_n_bits((int)(sizeof(_intrinsic_id) * BitsPerByte));
1511 assert((uintptr_t)vmIntrinsics::ID_LIMIT <= max_id_uint, "else fix size");
1512 assert(intrinsic_id_size_in_bytes() == sizeof(_intrinsic_id), "");
1513
1514 // the klass name is well-known:
1515 vmSymbols::SID klass_id = klass_id_for_intrinsics(method_holder());
1516 assert(klass_id != vmSymbols::NO_SID, "caller responsibility");
1517
1518 // ditto for method and signature:
1519 vmSymbols::SID name_id = vmSymbols::find_sid(name());
1520 if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1521 && klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle)
1522 && name_id == vmSymbols::NO_SID) {
1523 return;
1524 }
1525 vmSymbols::SID sig_id = vmSymbols::find_sid(signature());
1526 if (klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle)
1527 && klass_id != vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle)
1528 && sig_id == vmSymbols::NO_SID) {
1529 return;
1530 }
1531 jshort flags = access_flags().as_short();
1532
1533 vmIntrinsics::ID id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1534 if (id != vmIntrinsics::_none) {
1535 set_intrinsic_id(id);
1536 if (id == vmIntrinsics::_Class_cast) {
1537 // Even if the intrinsic is rejected, we want to inline this simple method.
1538 set_force_inline(true);
1539 }
1540 return;
1541 }
1542
1543 // A few slightly irregular cases:
1544 switch (klass_id) {
1545 case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_StrictMath):
1546 // Second chance: check in regular Math.
1547 switch (name_id) {
1548 case vmSymbols::VM_SYMBOL_ENUM_NAME(min_name):
1549 case vmSymbols::VM_SYMBOL_ENUM_NAME(max_name):
1550 case vmSymbols::VM_SYMBOL_ENUM_NAME(sqrt_name):
1551 // pretend it is the corresponding method in the non-strict class:
1552 klass_id = vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_Math);
1553 id = vmIntrinsics::find_id(klass_id, name_id, sig_id, flags);
1554 break;
1555 default:
1556 break;
1557 }
1558 break;
1559
1560 // Signature-polymorphic methods: MethodHandle.invoke*, InvokeDynamic.*., VarHandle
1561 case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_MethodHandle):
1562 case vmSymbols::VM_SYMBOL_ENUM_NAME(java_lang_invoke_VarHandle):
1563 if (!is_native()) break;
1564 id = MethodHandles::signature_polymorphic_name_id(method_holder(), name());
1565 if (is_static() != MethodHandles::is_signature_polymorphic_static(id))
1566 id = vmIntrinsics::_none;
1567 break;
1568
1569 default:
1570 break;
1571 }
1572
1573 if (id != vmIntrinsics::_none) {
1574 // Set up its iid. It is an alias method.
1575 set_intrinsic_id(id);
1576 return;
1577 }
1578 }
1579
1580 // These two methods are static since a GC may move the Method
1581 bool Method::load_signature_classes(const methodHandle& m, TRAPS) {
1582 if (!THREAD->can_call_java()) {
1583 // There is nothing useful this routine can do from within the Compile thread.
1584 // Hopefully, the signature contains only well-known classes.
1585 // We could scan for this and return true/false, but the caller won't care.
1586 return false;
1587 }
1588 bool sig_is_loaded = true;
1589 Handle class_loader(THREAD, m->method_holder()->class_loader());
1590 Handle protection_domain(THREAD, m->method_holder()->protection_domain());
1591 ResourceMark rm(THREAD);
1592 Symbol* signature = m->signature();
1593 for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
1594 if (ss.is_object()) {
1595 Symbol* sym = ss.as_symbol(CHECK_(false));
1596 Symbol* name = sym;
1597 Klass* klass = SystemDictionary::resolve_or_null(name, class_loader,
1598 protection_domain, THREAD);
1599 // We are loading classes eagerly. If a ClassNotFoundException or
1600 // a LinkageError was generated, be sure to ignore it.
1601 if (HAS_PENDING_EXCEPTION) {
1602 if (PENDING_EXCEPTION->is_a(SystemDictionary::ClassNotFoundException_klass()) ||
1603 PENDING_EXCEPTION->is_a(SystemDictionary::LinkageError_klass())) {
1604 CLEAR_PENDING_EXCEPTION;
1605 } else {
1606 return false;
1607 }
1608 }
1609 if( klass == NULL) { sig_is_loaded = false; }
1610 }
1611 }
1612 return sig_is_loaded;
1613 }
1614
1615 bool Method::has_unloaded_classes_in_signature(const methodHandle& m, TRAPS) {
1616 Handle class_loader(THREAD, m->method_holder()->class_loader());
1617 Handle protection_domain(THREAD, m->method_holder()->protection_domain());
1618 ResourceMark rm(THREAD);
1619 Symbol* signature = m->signature();
1620 for(SignatureStream ss(signature); !ss.is_done(); ss.next()) {
1621 if (ss.type() == T_OBJECT) {
1622 Symbol* name = ss.as_symbol_or_null();
1623 if (name == NULL) return true;
1624 Klass* klass = SystemDictionary::find(name, class_loader, protection_domain, THREAD);
1625 if (klass == NULL) return true;
1626 }
1627 }
1628 return false;
1629 }
1630
1631 // Exposed so field engineers can debug VM
1632 void Method::print_short_name(outputStream* st) {
1633 ResourceMark rm;
1634 #ifdef PRODUCT
1635 st->print(" %s::", method_holder()->external_name());
1636 #else
1637 st->print(" %s::", method_holder()->internal_name());
1638 #endif
1639 name()->print_symbol_on(st);
1640 if (WizardMode) signature()->print_symbol_on(st);
1641 else if (MethodHandles::is_signature_polymorphic(intrinsic_id()))
1642 MethodHandles::print_as_basic_type_signature_on(st, signature(), true);
1643 }
1644
1645 // Comparer for sorting an object array containing
1646 // Method*s.
1647 static int method_comparator(Method* a, Method* b) {
1648 return a->name()->fast_compare(b->name());
1649 }
1650
1651 // This is only done during class loading, so it is OK to assume method_idnum matches the methods() array
1652 // default_methods also uses this without the ordering for fast find_method
1653 void Method::sort_methods(Array<Method*>* methods, bool idempotent, bool set_idnums) {
1654 int length = methods->length();
1655 if (length > 1) {
1656 {
1657 NoSafepointVerifier nsv;
1658 QuickSort::sort(methods->data(), length, method_comparator, idempotent);
1659 }
1660 // Reset method ordering
1661 if (set_idnums) {
1662 for (int i = 0; i < length; i++) {
1663 Method* m = methods->at(i);
1664 m->set_method_idnum(i);
1665 m->set_orig_method_idnum(i);
1666 }
1667 }
1668 }
1669 }
1670
1671 //-----------------------------------------------------------------------------------
1672 // Non-product code unless JVM/TI needs it
1673
1674 #if !defined(PRODUCT) || INCLUDE_JVMTI
1675 class SignatureTypePrinter : public SignatureTypeNames {
1676 private:
1677 outputStream* _st;
1678 bool _use_separator;
1679
1680 void type_name(const char* name) {
1681 if (_use_separator) _st->print(", ");
1682 _st->print("%s", name);
1683 _use_separator = true;
1684 }
1685
1686 public:
1687 SignatureTypePrinter(Symbol* signature, outputStream* st) : SignatureTypeNames(signature) {
1688 _st = st;
1689 _use_separator = false;
1690 }
1691
1692 void print_parameters() { _use_separator = false; iterate_parameters(); }
1693 void print_returntype() { _use_separator = false; iterate_returntype(); }
1694 };
1695
1696
1697 void Method::print_name(outputStream* st) {
1698 Thread *thread = Thread::current();
1699 ResourceMark rm(thread);
1700 st->print("%s ", is_static() ? "static" : "virtual");
1701 if (WizardMode) {
1702 st->print("%s.", method_holder()->internal_name());
1703 name()->print_symbol_on(st);
1704 signature()->print_symbol_on(st);
1705 } else {
1706 SignatureTypePrinter sig(signature(), st);
1707 sig.print_returntype();
1708 st->print(" %s.", method_holder()->internal_name());
1709 name()->print_symbol_on(st);
1710 st->print("(");
1711 sig.print_parameters();
1712 st->print(")");
1713 }
1714 }
1715 #endif // !PRODUCT || INCLUDE_JVMTI
1716
1717
1718 void Method::print_codes_on(outputStream* st) const {
1719 print_codes_on(0, code_size(), st);
1720 }
1721
1722 void Method::print_codes_on(int from, int to, outputStream* st) const {
1723 Thread *thread = Thread::current();
1724 ResourceMark rm(thread);
1725 methodHandle mh (thread, (Method*)this);
1726 BytecodeStream s(mh);
1727 s.set_interval(from, to);
1728 BytecodeTracer::set_closure(BytecodeTracer::std_closure());
1729 while (s.next() >= 0) BytecodeTracer::trace(mh, s.bcp(), st);
1730 }
1731
1732
1733 // Simple compression of line number tables. We use a regular compressed stream, except that we compress deltas
1734 // between (bci,line) pairs since they are smaller. If (bci delta, line delta) fits in (5-bit unsigned, 3-bit unsigned)
1735 // we save it as one byte, otherwise we write a 0xFF escape character and use regular compression. 0x0 is used
1736 // as end-of-stream terminator.
1737
1738 void CompressedLineNumberWriteStream::write_pair_regular(int bci_delta, int line_delta) {
1739 // bci and line number does not compress into single byte.
1740 // Write out escape character and use regular compression for bci and line number.
1741 write_byte((jubyte)0xFF);
1742 write_signed_int(bci_delta);
1743 write_signed_int(line_delta);
1744 }
1745
1746 // See comment in method.hpp which explains why this exists.
1747 #if defined(_M_AMD64) && _MSC_VER >= 1400
1748 #pragma optimize("", off)
1749 void CompressedLineNumberWriteStream::write_pair(int bci, int line) {
1750 write_pair_inline(bci, line);
1751 }
1752 #pragma optimize("", on)
1753 #endif
1754
1755 CompressedLineNumberReadStream::CompressedLineNumberReadStream(u_char* buffer) : CompressedReadStream(buffer) {
1756 _bci = 0;
1757 _line = 0;
1758 };
1759
1760
1761 bool CompressedLineNumberReadStream::read_pair() {
1762 jubyte next = read_byte();
1763 // Check for terminator
1764 if (next == 0) return false;
1765 if (next == 0xFF) {
1766 // Escape character, regular compression used
1767 _bci += read_signed_int();
1768 _line += read_signed_int();
1769 } else {
1770 // Single byte compression used
1771 _bci += next >> 3;
1772 _line += next & 0x7;
1773 }
1774 return true;
1775 }
1776
1777 #if INCLUDE_JVMTI
1778
1779 Bytecodes::Code Method::orig_bytecode_at(int bci) const {
1780 BreakpointInfo* bp = method_holder()->breakpoints();
1781 for (; bp != NULL; bp = bp->next()) {
1782 if (bp->match(this, bci)) {
1783 return bp->orig_bytecode();
1784 }
1785 }
1786 {
1787 ResourceMark rm;
1788 fatal("no original bytecode found in %s at bci %d", name_and_sig_as_C_string(), bci);
1789 }
1790 return Bytecodes::_shouldnotreachhere;
1791 }
1792
1793 void Method::set_orig_bytecode_at(int bci, Bytecodes::Code code) {
1794 assert(code != Bytecodes::_breakpoint, "cannot patch breakpoints this way");
1795 BreakpointInfo* bp = method_holder()->breakpoints();
1796 for (; bp != NULL; bp = bp->next()) {
1797 if (bp->match(this, bci)) {
1798 bp->set_orig_bytecode(code);
1799 // and continue, in case there is more than one
1800 }
1801 }
1802 }
1803
1804 void Method::set_breakpoint(int bci) {
1805 InstanceKlass* ik = method_holder();
1806 BreakpointInfo *bp = new BreakpointInfo(this, bci);
1807 bp->set_next(ik->breakpoints());
1808 ik->set_breakpoints(bp);
1809 // do this last:
1810 bp->set(this);
1811 }
1812
1813 static void clear_matches(Method* m, int bci) {
1814 InstanceKlass* ik = m->method_holder();
1815 BreakpointInfo* prev_bp = NULL;
1816 BreakpointInfo* next_bp;
1817 for (BreakpointInfo* bp = ik->breakpoints(); bp != NULL; bp = next_bp) {
1818 next_bp = bp->next();
1819 // bci value of -1 is used to delete all breakpoints in method m (ex: clear_all_breakpoint).
1820 if (bci >= 0 ? bp->match(m, bci) : bp->match(m)) {
1821 // do this first:
1822 bp->clear(m);
1823 // unhook it
1824 if (prev_bp != NULL)
1825 prev_bp->set_next(next_bp);
1826 else
1827 ik->set_breakpoints(next_bp);
1828 delete bp;
1829 // When class is redefined JVMTI sets breakpoint in all versions of EMCP methods
1830 // at same location. So we have multiple matching (method_index and bci)
1831 // BreakpointInfo nodes in BreakpointInfo list. We should just delete one
1832 // breakpoint for clear_breakpoint request and keep all other method versions
1833 // BreakpointInfo for future clear_breakpoint request.
1834 // bcivalue of -1 is used to clear all breakpoints (see clear_all_breakpoints)
1835 // which is being called when class is unloaded. We delete all the Breakpoint
1836 // information for all versions of method. We may not correctly restore the original
1837 // bytecode in all method versions, but that is ok. Because the class is being unloaded
1838 // so these methods won't be used anymore.
1839 if (bci >= 0) {
1840 break;
1841 }
1842 } else {
1843 // This one is a keeper.
1844 prev_bp = bp;
1845 }
1846 }
1847 }
1848
1849 void Method::clear_breakpoint(int bci) {
1850 assert(bci >= 0, "");
1851 clear_matches(this, bci);
1852 }
1853
1854 void Method::clear_all_breakpoints() {
1855 clear_matches(this, -1);
1856 }
1857
1858 #endif // INCLUDE_JVMTI
1859
1860 int Method::invocation_count() {
1861 MethodCounters *mcs = method_counters();
1862 if (TieredCompilation) {
1863 MethodData* const mdo = method_data();
1864 if (((mcs != NULL) ? mcs->invocation_counter()->carry() : false) ||
1865 ((mdo != NULL) ? mdo->invocation_counter()->carry() : false)) {
1866 return InvocationCounter::count_limit;
1867 } else {
1868 return ((mcs != NULL) ? mcs->invocation_counter()->count() : 0) +
1869 ((mdo != NULL) ? mdo->invocation_counter()->count() : 0);
1870 }
1871 } else {
1872 return (mcs == NULL) ? 0 : mcs->invocation_counter()->count();
1873 }
1874 }
1875
1876 int Method::backedge_count() {
1877 MethodCounters *mcs = method_counters();
1878 if (TieredCompilation) {
1879 MethodData* const mdo = method_data();
1880 if (((mcs != NULL) ? mcs->backedge_counter()->carry() : false) ||
1881 ((mdo != NULL) ? mdo->backedge_counter()->carry() : false)) {
1882 return InvocationCounter::count_limit;
1883 } else {
1884 return ((mcs != NULL) ? mcs->backedge_counter()->count() : 0) +
1885 ((mdo != NULL) ? mdo->backedge_counter()->count() : 0);
1886 }
1887 } else {
1888 return (mcs == NULL) ? 0 : mcs->backedge_counter()->count();
1889 }
1890 }
1891
1892 int Method::highest_comp_level() const {
1893 const MethodCounters* mcs = method_counters();
1894 if (mcs != NULL) {
1895 return mcs->highest_comp_level();
1896 } else {
1897 return CompLevel_none;
1898 }
1899 }
1900
1901 int Method::highest_osr_comp_level() const {
1902 const MethodCounters* mcs = method_counters();
1903 if (mcs != NULL) {
1904 return mcs->highest_osr_comp_level();
1905 } else {
1906 return CompLevel_none;
1907 }
1908 }
1909
1910 void Method::set_highest_comp_level(int level) {
1911 MethodCounters* mcs = method_counters();
1912 if (mcs != NULL) {
1913 mcs->set_highest_comp_level(level);
1914 }
1915 }
1916
1917 void Method::set_highest_osr_comp_level(int level) {
1918 MethodCounters* mcs = method_counters();
1919 if (mcs != NULL) {
1920 mcs->set_highest_osr_comp_level(level);
1921 }
1922 }
1923
1924 #if INCLUDE_JVMTI
1925
1926 BreakpointInfo::BreakpointInfo(Method* m, int bci) {
1927 _bci = bci;
1928 _name_index = m->name_index();
1929 _signature_index = m->signature_index();
1930 _orig_bytecode = (Bytecodes::Code) *m->bcp_from(_bci);
1931 if (_orig_bytecode == Bytecodes::_breakpoint)
1932 _orig_bytecode = m->orig_bytecode_at(_bci);
1933 _next = NULL;
1934 }
1935
1936 void BreakpointInfo::set(Method* method) {
1937 #ifdef ASSERT
1938 {
1939 Bytecodes::Code code = (Bytecodes::Code) *method->bcp_from(_bci);
1940 if (code == Bytecodes::_breakpoint)
1941 code = method->orig_bytecode_at(_bci);
1942 assert(orig_bytecode() == code, "original bytecode must be the same");
1943 }
1944 #endif
1945 Thread *thread = Thread::current();
1946 *method->bcp_from(_bci) = Bytecodes::_breakpoint;
1947 method->incr_number_of_breakpoints(thread);
1948 SystemDictionary::notice_modification();
1949 {
1950 // Deoptimize all dependents on this method
1951 HandleMark hm(thread);
1952 methodHandle mh(thread, method);
1953 CodeCache::flush_dependents_on_method(mh);
1954 }
1955 }
1956
1957 void BreakpointInfo::clear(Method* method) {
1958 *method->bcp_from(_bci) = orig_bytecode();
1959 assert(method->number_of_breakpoints() > 0, "must not go negative");
1960 method->decr_number_of_breakpoints(Thread::current());
1961 }
1962
1963 #endif // INCLUDE_JVMTI
1964
1965 // jmethodID handling
1966
1967 // This is a block allocating object, sort of like JNIHandleBlock, only a
1968 // lot simpler.
1969 // It's allocated on the CHeap because once we allocate a jmethodID, we can
1970 // never get rid of it.
1971
1972 static const int min_block_size = 8;
1973
1974 class JNIMethodBlockNode : public CHeapObj<mtClass> {
1975 friend class JNIMethodBlock;
1976 Method** _methods;
1977 int _number_of_methods;
1978 int _top;
1979 JNIMethodBlockNode* _next;
1980
1981 public:
1982
1983 JNIMethodBlockNode(int num_methods = min_block_size);
1984
1985 ~JNIMethodBlockNode() { FREE_C_HEAP_ARRAY(Method*, _methods); }
1986
1987 void ensure_methods(int num_addl_methods) {
1988 if (_top < _number_of_methods) {
1989 num_addl_methods -= _number_of_methods - _top;
1990 if (num_addl_methods <= 0) {
1991 return;
1992 }
1993 }
1994 if (_next == NULL) {
1995 _next = new JNIMethodBlockNode(MAX2(num_addl_methods, min_block_size));
1996 } else {
1997 _next->ensure_methods(num_addl_methods);
1998 }
1999 }
2000 };
2001
2002 class JNIMethodBlock : public CHeapObj<mtClass> {
2003 JNIMethodBlockNode _head;
2004 JNIMethodBlockNode *_last_free;
2005 public:
2006 static Method* const _free_method;
2007
2008 JNIMethodBlock(int initial_capacity = min_block_size)
2009 : _head(initial_capacity), _last_free(&_head) {}
2010
2011 void ensure_methods(int num_addl_methods) {
2012 _last_free->ensure_methods(num_addl_methods);
2013 }
2014
2015 Method** add_method(Method* m) {
2016 for (JNIMethodBlockNode* b = _last_free; b != NULL; b = b->_next) {
2017 if (b->_top < b->_number_of_methods) {
2018 // top points to the next free entry.
2019 int i = b->_top;
2020 b->_methods[i] = m;
2021 b->_top++;
2022 _last_free = b;
2023 return &(b->_methods[i]);
2024 } else if (b->_top == b->_number_of_methods) {
2025 // if the next free entry ran off the block see if there's a free entry
2026 for (int i = 0; i < b->_number_of_methods; i++) {
2027 if (b->_methods[i] == _free_method) {
2028 b->_methods[i] = m;
2029 _last_free = b;
2030 return &(b->_methods[i]);
2031 }
2032 }
2033 // Only check each block once for frees. They're very unlikely.
2034 // Increment top past the end of the block.
2035 b->_top++;
2036 }
2037 // need to allocate a next block.
2038 if (b->_next == NULL) {
2039 b->_next = _last_free = new JNIMethodBlockNode();
2040 }
2041 }
2042 guarantee(false, "Should always allocate a free block");
2043 return NULL;
2044 }
2045
2046 bool contains(Method** m) {
2047 if (m == NULL) return false;
2048 for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2049 if (b->_methods <= m && m < b->_methods + b->_number_of_methods) {
2050 // This is a bit of extra checking, for two reasons. One is
2051 // that contains() deals with pointers that are passed in by
2052 // JNI code, so making sure that the pointer is aligned
2053 // correctly is valuable. The other is that <= and > are
2054 // technically not defined on pointers, so the if guard can
2055 // pass spuriously; no modern compiler is likely to make that
2056 // a problem, though (and if one did, the guard could also
2057 // fail spuriously, which would be bad).
2058 ptrdiff_t idx = m - b->_methods;
2059 if (b->_methods + idx == m) {
2060 return true;
2061 }
2062 }
2063 }
2064 return false; // not found
2065 }
2066
2067 // Doesn't really destroy it, just marks it as free so it can be reused.
2068 void destroy_method(Method** m) {
2069 #ifdef ASSERT
2070 assert(contains(m), "should be a methodID");
2071 #endif // ASSERT
2072 *m = _free_method;
2073 }
2074
2075 // During class unloading the methods are cleared, which is different
2076 // than freed.
2077 void clear_all_methods() {
2078 for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2079 for (int i = 0; i< b->_number_of_methods; i++) {
2080 b->_methods[i] = NULL;
2081 }
2082 }
2083 }
2084 #ifndef PRODUCT
2085 int count_methods() {
2086 // count all allocated methods
2087 int count = 0;
2088 for (JNIMethodBlockNode* b = &_head; b != NULL; b = b->_next) {
2089 for (int i = 0; i< b->_number_of_methods; i++) {
2090 if (b->_methods[i] != _free_method) count++;
2091 }
2092 }
2093 return count;
2094 }
2095 #endif // PRODUCT
2096 };
2097
2098 // Something that can't be mistaken for an address or a markOop
2099 Method* const JNIMethodBlock::_free_method = (Method*)55;
2100
2101 JNIMethodBlockNode::JNIMethodBlockNode(int num_methods) : _next(NULL), _top(0) {
2102 _number_of_methods = MAX2(num_methods, min_block_size);
2103 _methods = NEW_C_HEAP_ARRAY(Method*, _number_of_methods, mtInternal);
2104 for (int i = 0; i < _number_of_methods; i++) {
2105 _methods[i] = JNIMethodBlock::_free_method;
2106 }
2107 }
2108
2109 void Method::ensure_jmethod_ids(ClassLoaderData* loader_data, int capacity) {
2110 ClassLoaderData* cld = loader_data;
2111 if (!SafepointSynchronize::is_at_safepoint()) {
2112 // Have to add jmethod_ids() to class loader data thread-safely.
2113 // Also have to add the method to the list safely, which the cld lock
2114 // protects as well.
2115 MutexLockerEx ml(cld->metaspace_lock(), Mutex::_no_safepoint_check_flag);
2116 if (cld->jmethod_ids() == NULL) {
2117 cld->set_jmethod_ids(new JNIMethodBlock(capacity));
2118 } else {
2119 cld->jmethod_ids()->ensure_methods(capacity);
2120 }
2121 } else {
2122 // At safepoint, we are single threaded and can set this.
2123 if (cld->jmethod_ids() == NULL) {
2124 cld->set_jmethod_ids(new JNIMethodBlock(capacity));
2125 } else {
2126 cld->jmethod_ids()->ensure_methods(capacity);
2127 }
2128 }
2129 }
2130
2131 // Add a method id to the jmethod_ids
2132 jmethodID Method::make_jmethod_id(ClassLoaderData* loader_data, Method* m) {
2133 ClassLoaderData* cld = loader_data;
2134
2135 if (!SafepointSynchronize::is_at_safepoint()) {
2136 // Have to add jmethod_ids() to class loader data thread-safely.
2137 // Also have to add the method to the list safely, which the cld lock
2138 // protects as well.
2139 MutexLockerEx ml(cld->metaspace_lock(), Mutex::_no_safepoint_check_flag);
2140 if (cld->jmethod_ids() == NULL) {
2141 cld->set_jmethod_ids(new JNIMethodBlock());
2142 }
2143 // jmethodID is a pointer to Method*
2144 return (jmethodID)cld->jmethod_ids()->add_method(m);
2145 } else {
2146 // At safepoint, we are single threaded and can set this.
2147 if (cld->jmethod_ids() == NULL) {
2148 cld->set_jmethod_ids(new JNIMethodBlock());
2149 }
2150 // jmethodID is a pointer to Method*
2151 return (jmethodID)cld->jmethod_ids()->add_method(m);
2152 }
2153 }
2154
2155 // Mark a jmethodID as free. This is called when there is a data race in
2156 // InstanceKlass while creating the jmethodID cache.
2157 void Method::destroy_jmethod_id(ClassLoaderData* loader_data, jmethodID m) {
2158 ClassLoaderData* cld = loader_data;
2159 Method** ptr = (Method**)m;
2160 assert(cld->jmethod_ids() != NULL, "should have method handles");
2161 cld->jmethod_ids()->destroy_method(ptr);
2162 }
2163
2164 void Method::change_method_associated_with_jmethod_id(jmethodID jmid, Method* new_method) {
2165 // Can't assert the method_holder is the same because the new method has the
2166 // scratch method holder.
2167 assert(resolve_jmethod_id(jmid)->method_holder()->class_loader()
2168 == new_method->method_holder()->class_loader() ||
2169 new_method->method_holder()->class_loader() == NULL, // allow Unsafe substitution
2170 "changing to a different class loader");
2171 // Just change the method in place, jmethodID pointer doesn't change.
2172 *((Method**)jmid) = new_method;
2173 }
2174
2175 bool Method::is_method_id(jmethodID mid) {
2176 Method* m = resolve_jmethod_id(mid);
2177 assert(m != NULL, "should be called with non-null method");
2178 InstanceKlass* ik = m->method_holder();
2179 ClassLoaderData* cld = ik->class_loader_data();
2180 if (cld->jmethod_ids() == NULL) return false;
2181 return (cld->jmethod_ids()->contains((Method**)mid));
2182 }
2183
2184 Method* Method::checked_resolve_jmethod_id(jmethodID mid) {
2185 if (mid == NULL) return NULL;
2186 Method* o = resolve_jmethod_id(mid);
2187 if (o == NULL || o == JNIMethodBlock::_free_method || !((Metadata*)o)->is_method()) {
2188 return NULL;
2189 }
2190 return o;
2191 };
2192
2193 void Method::set_on_stack(const bool value) {
2194 // Set both the method itself and its constant pool. The constant pool
2195 // on stack means some method referring to it is also on the stack.
2196 constants()->set_on_stack(value);
2197
2198 bool already_set = on_stack();
2199 _access_flags.set_on_stack(value);
2200 if (value && !already_set) {
2201 MetadataOnStackMark::record(this);
2202 }
2203 }
2204
2205 // Called when the class loader is unloaded to make all methods weak.
2206 void Method::clear_jmethod_ids(ClassLoaderData* loader_data) {
2207 loader_data->jmethod_ids()->clear_all_methods();
2208 }
2209
2210 bool Method::has_method_vptr(const void* ptr) {
2211 Method m;
2212 // This assumes that the vtbl pointer is the first word of a C++ object.
2213 return dereference_vptr(&m) == dereference_vptr(ptr);
2214 }
2215
2216 // Check that this pointer is valid by checking that the vtbl pointer matches
2217 bool Method::is_valid_method() const {
2218 if (this == NULL) {
2219 return false;
2220 } else if ((intptr_t(this) & (wordSize-1)) != 0) {
2221 // Quick sanity check on pointer.
2222 return false;
2223 } else if (is_shared()) {
2224 return MetaspaceShared::is_valid_shared_method(this);
2225 } else if (Metaspace::contains_non_shared(this)) {
2226 return has_method_vptr((const void*)this);
2227 } else {
2228 return false;
2229 }
2230 }
2231
2232 #ifndef PRODUCT
2233 void Method::print_jmethod_ids(const ClassLoaderData* loader_data, outputStream* out) {
2234 out->print(" jni_method_id count = %d", loader_data->jmethod_ids()->count_methods());
2235 }
2236 #endif // PRODUCT
2237
2238
2239 // Printing
2240
2241 #ifndef PRODUCT
2242
2243 void Method::print_on(outputStream* st) const {
2244 ResourceMark rm;
2245 assert(is_method(), "must be method");
2246 st->print_cr("%s", internal_name());
2247 st->print_cr(" - this oop: " INTPTR_FORMAT, p2i(this));
2248 st->print (" - method holder: "); method_holder()->print_value_on(st); st->cr();
2249 st->print (" - constants: " INTPTR_FORMAT " ", p2i(constants()));
2250 constants()->print_value_on(st); st->cr();
2251 st->print (" - access: 0x%x ", access_flags().as_int()); access_flags().print_on(st); st->cr();
2252 st->print (" - name: "); name()->print_value_on(st); st->cr();
2253 st->print (" - signature: "); signature()->print_value_on(st); st->cr();
2254 st->print_cr(" - max stack: %d", max_stack());
2255 st->print_cr(" - max locals: %d", max_locals());
2256 st->print_cr(" - size of params: %d", size_of_parameters());
2257 st->print_cr(" - method size: %d", method_size());
2258 if (intrinsic_id() != vmIntrinsics::_none)
2259 st->print_cr(" - intrinsic id: %d %s", intrinsic_id(), vmIntrinsics::name_at(intrinsic_id()));
2260 if (highest_comp_level() != CompLevel_none)
2261 st->print_cr(" - highest level: %d", highest_comp_level());
2262 st->print_cr(" - vtable index: %d", _vtable_index);
2263 st->print_cr(" - i2i entry: " INTPTR_FORMAT, p2i(interpreter_entry()));
2264 st->print( " - adapters: ");
2265 AdapterHandlerEntry* a = ((Method*)this)->adapter();
2266 if (a == NULL)
2267 st->print_cr(INTPTR_FORMAT, p2i(a));
2268 else
2269 a->print_adapter_on(st);
2270 st->print_cr(" - compiled entry " INTPTR_FORMAT, p2i(from_compiled_entry()));
2271 st->print_cr(" - code size: %d", code_size());
2272 if (code_size() != 0) {
2273 st->print_cr(" - code start: " INTPTR_FORMAT, p2i(code_base()));
2274 st->print_cr(" - code end (excl): " INTPTR_FORMAT, p2i(code_base() + code_size()));
2275 }
2276 if (method_data() != NULL) {
2277 st->print_cr(" - method data: " INTPTR_FORMAT, p2i(method_data()));
2278 }
2279 st->print_cr(" - checked ex length: %d", checked_exceptions_length());
2280 if (checked_exceptions_length() > 0) {
2281 CheckedExceptionElement* table = checked_exceptions_start();
2282 st->print_cr(" - checked ex start: " INTPTR_FORMAT, p2i(table));
2283 if (Verbose) {
2284 for (int i = 0; i < checked_exceptions_length(); i++) {
2285 st->print_cr(" - throws %s", constants()->printable_name_at(table[i].class_cp_index));
2286 }
2287 }
2288 }
2289 if (has_linenumber_table()) {
2290 u_char* table = compressed_linenumber_table();
2291 st->print_cr(" - linenumber start: " INTPTR_FORMAT, p2i(table));
2292 if (Verbose) {
2293 CompressedLineNumberReadStream stream(table);
2294 while (stream.read_pair()) {
2295 st->print_cr(" - line %d: %d", stream.line(), stream.bci());
2296 }
2297 }
2298 }
2299 st->print_cr(" - localvar length: %d", localvariable_table_length());
2300 if (localvariable_table_length() > 0) {
2301 LocalVariableTableElement* table = localvariable_table_start();
2302 st->print_cr(" - localvar start: " INTPTR_FORMAT, p2i(table));
2303 if (Verbose) {
2304 for (int i = 0; i < localvariable_table_length(); i++) {
2305 int bci = table[i].start_bci;
2306 int len = table[i].length;
2307 const char* name = constants()->printable_name_at(table[i].name_cp_index);
2308 const char* desc = constants()->printable_name_at(table[i].descriptor_cp_index);
2309 int slot = table[i].slot;
2310 st->print_cr(" - %s %s bci=%d len=%d slot=%d", desc, name, bci, len, slot);
2311 }
2312 }
2313 }
2314 if (code() != NULL) {
2315 st->print (" - compiled code: ");
2316 code()->print_value_on(st);
2317 }
2318 if (is_native()) {
2319 st->print_cr(" - native function: " INTPTR_FORMAT, p2i(native_function()));
2320 st->print_cr(" - signature handler: " INTPTR_FORMAT, p2i(signature_handler()));
2321 }
2322 }
2323
2324 void Method::print_linkage_flags(outputStream* st) {
2325 access_flags().print_on(st);
2326 if (is_default_method()) {
2327 st->print("default ");
2328 }
2329 if (is_overpass()) {
2330 st->print("overpass ");
2331 }
2332 }
2333 #endif //PRODUCT
2334
2335 void Method::print_value_on(outputStream* st) const {
2336 assert(is_method(), "must be method");
2337 st->print("%s", internal_name());
2338 print_address_on(st);
2339 st->print(" ");
2340 name()->print_value_on(st);
2341 st->print(" ");
2342 signature()->print_value_on(st);
2343 st->print(" in ");
2344 method_holder()->print_value_on(st);
2345 if (WizardMode) st->print("#%d", _vtable_index);
2346 if (WizardMode) st->print("[%d,%d]", size_of_parameters(), max_locals());
2347 if (WizardMode && code() != NULL) st->print(" ((nmethod*)%p)", code());
2348 }
2349
2350 #if INCLUDE_SERVICES
2351 // Size Statistics
2352 void Method::collect_statistics(KlassSizeStats *sz) const {
2353 int mysize = sz->count(this);
2354 sz->_method_bytes += mysize;
2355 sz->_method_all_bytes += mysize;
2356 sz->_rw_bytes += mysize;
2357
2358 if (constMethod()) {
2359 constMethod()->collect_statistics(sz);
2360 }
2361 if (method_data()) {
2362 method_data()->collect_statistics(sz);
2363 }
2364 }
2365 #endif // INCLUDE_SERVICES
2366
2367 // LogTouchedMethods and PrintTouchedMethods
2368
2369 // TouchedMethodRecord -- we can't use a HashtableEntry<Method*> because
2370 // the Method may be garbage collected. Let's roll our own hash table.
2371 class TouchedMethodRecord : CHeapObj<mtTracing> {
2372 public:
2373 // It's OK to store Symbols here because they will NOT be GC'ed if
2374 // LogTouchedMethods is enabled.
2375 TouchedMethodRecord* _next;
2376 Symbol* _class_name;
2377 Symbol* _method_name;
2378 Symbol* _method_signature;
2379 };
2380
2381 static const int TOUCHED_METHOD_TABLE_SIZE = 20011;
2382 static TouchedMethodRecord** _touched_method_table = NULL;
2383
2384 void Method::log_touched(TRAPS) {
2385
2386 const int table_size = TOUCHED_METHOD_TABLE_SIZE;
2387 Symbol* my_class = klass_name();
2388 Symbol* my_name = name();
2389 Symbol* my_sig = signature();
2390
2391 unsigned int hash = my_class->identity_hash() +
2392 my_name->identity_hash() +
2393 my_sig->identity_hash();
2394 juint index = juint(hash) % table_size;
2395
2396 MutexLocker ml(TouchedMethodLog_lock, THREAD);
2397 if (_touched_method_table == NULL) {
2398 _touched_method_table = NEW_C_HEAP_ARRAY2(TouchedMethodRecord*, table_size,
2399 mtTracing, CURRENT_PC);
2400 memset(_touched_method_table, 0, sizeof(TouchedMethodRecord*)*table_size);
2401 }
2402
2403 TouchedMethodRecord* ptr = _touched_method_table[index];
2404 while (ptr) {
2405 if (ptr->_class_name == my_class &&
2406 ptr->_method_name == my_name &&
2407 ptr->_method_signature == my_sig) {
2408 return;
2409 }
2410 if (ptr->_next == NULL) break;
2411 ptr = ptr->_next;
2412 }
2413 TouchedMethodRecord* nptr = NEW_C_HEAP_OBJ(TouchedMethodRecord, mtTracing);
2414 my_class->increment_refcount();
2415 my_name->increment_refcount();
2416 my_sig->increment_refcount();
2417 nptr->_class_name = my_class;
2418 nptr->_method_name = my_name;
2419 nptr->_method_signature = my_sig;
2420 nptr->_next = NULL;
2421
2422 if (ptr == NULL) {
2423 // first
2424 _touched_method_table[index] = nptr;
2425 } else {
2426 ptr->_next = nptr;
2427 }
2428 }
2429
2430 void Method::print_touched_methods(outputStream* out) {
2431 MutexLockerEx ml(Thread::current()->is_VM_thread() ? NULL : TouchedMethodLog_lock);
2432 out->print_cr("# Method::print_touched_methods version 1");
2433 if (_touched_method_table) {
2434 for (int i = 0; i < TOUCHED_METHOD_TABLE_SIZE; i++) {
2435 TouchedMethodRecord* ptr = _touched_method_table[i];
2436 while(ptr) {
2437 ptr->_class_name->print_symbol_on(out); out->print(".");
2438 ptr->_method_name->print_symbol_on(out); out->print(":");
2439 ptr->_method_signature->print_symbol_on(out); out->cr();
2440 ptr = ptr->_next;
2441 }
2442 }
2443 }
2444 }
2445
2446 // Verification
2447
2448 void Method::verify_on(outputStream* st) {
2449 guarantee(is_method(), "object must be method");
2450 guarantee(constants()->is_constantPool(), "should be constant pool");
2451 guarantee(constMethod()->is_constMethod(), "should be ConstMethod*");
2452 MethodData* md = method_data();
2453 guarantee(md == NULL ||
2454 md->is_methodData(), "should be method data");
2455 }