1 /*
2 * Copyright (c) 1997, 2025, 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 "classfile/vmSymbols.hpp"
26 #include "interpreter/bytecodeStream.hpp"
27 #include "logging/log.hpp"
28 #include "logging/logStream.hpp"
29 #include "memory/allocation.inline.hpp"
30 #include "memory/resourceArea.hpp"
31 #include "oops/constantPool.hpp"
32 #include "oops/generateOopMap.hpp"
33 #include "oops/oop.inline.hpp"
34 #include "oops/symbol.hpp"
35 #include "runtime/handles.inline.hpp"
36 #include "runtime/java.hpp"
37 #include "runtime/os.hpp"
38 #include "runtime/relocator.hpp"
39 #include "runtime/timerTrace.hpp"
40 #include "utilities/bitMap.inline.hpp"
41 #include "utilities/ostream.hpp"
42
43 //
44 //
45 // Compute stack layouts for each instruction in method.
46 //
47 // Problems:
48 // - What to do about jsr with different types of local vars?
49 // Need maps that are conditional on jsr path?
50 // - Jsr and exceptions should be done more efficiently (the retAddr stuff)
51 //
52 // Alternative:
53 // - Could extend verifier to provide this information.
54 // For: one fewer abstract interpreter to maintain. Against: the verifier
55 // solves a bigger problem so slower (undesirable to force verification of
56 // everything?).
57 //
58 // Algorithm:
59 // Partition bytecodes into basic blocks
60 // For each basic block: store entry state (vars, stack). For instructions
61 // inside basic blocks we do not store any state (instead we recompute it
62 // from state produced by previous instruction).
63 //
64 // Perform abstract interpretation of bytecodes over this lattice:
65 //
66 // _--'#'--_
67 // / / \ \
68 // / / \ \
69 // / | | \
70 // 'r' 'v' 'p' ' '
71 // \ | | /
72 // \ \ / /
73 // \ \ / /
74 // -- '@' --
75 //
76 // '#' top, result of conflict merge
77 // 'r' reference type
78 // 'v' value type
79 // 'p' pc type for jsr/ret
80 // ' ' uninitialized; never occurs on operand stack in Java
81 // '@' bottom/unexecuted; initial state each bytecode.
82 //
83 // Basic block headers are the only merge points. We use this iteration to
84 // compute the information:
85 //
86 // find basic blocks;
87 // initialize them with uninitialized state;
88 // initialize first BB according to method signature;
89 // mark first BB changed
90 // while (some BB is changed) do {
91 // perform abstract interpration of all bytecodes in BB;
92 // merge exit state of BB into entry state of all successor BBs,
93 // noting if any of these change;
94 // }
95 //
96 // One additional complication is necessary. The jsr instruction pushes
97 // a return PC on the stack (a 'p' type in the abstract interpretation).
98 // To be able to process "ret" bytecodes, we keep track of these return
99 // PC's in a 'retAddrs' structure in abstract interpreter context (when
100 // processing a "ret" bytecodes, it is not sufficient to know that it gets
101 // an argument of the right type 'p'; we need to know which address it
102 // returns to).
103 //
104 // (Note this comment is borrowed form the original author of the algorithm)
105
106 // ComputeCallStack
107 //
108 // Specialization of SignatureIterator - compute the effects of a call
109 //
110 class ComputeCallStack : public SignatureIterator {
111 CellTypeState *_effect;
112 int _idx;
113
114 void setup();
115 void set(CellTypeState state) { _effect[_idx++] = state; }
116 int length() { return _idx; };
117
118 friend class SignatureIterator; // so do_parameters_on can call do_type
119 void do_type(BasicType type, bool for_return = false) {
120 if (for_return && type == T_VOID) {
121 set(CellTypeState::bottom);
122 } else if (is_reference_type(type)) {
123 set(CellTypeState::ref);
124 } else {
125 assert(is_java_primitive(type), "");
126 set(CellTypeState::value);
127 if (is_double_word_type(type)) {
128 set(CellTypeState::value);
129 }
130 }
131 }
132
133 public:
134 ComputeCallStack(Symbol* signature) : SignatureIterator(signature) {};
135
136 // Compute methods
137 int compute_for_parameters(bool is_static, CellTypeState *effect) {
138 _idx = 0;
139 _effect = effect;
140
141 if (!is_static) {
142 effect[_idx++] = CellTypeState::ref;
143 }
144
145 do_parameters_on(this);
146
147 return length();
148 };
149
150 int compute_for_returntype(CellTypeState *effect) {
151 _idx = 0;
152 _effect = effect;
153 do_type(return_type(), true);
154 set(CellTypeState::bottom); // Always terminate with a bottom state, so ppush works
155
156 return length();
157 }
158 };
159
160 //=========================================================================================
161 // ComputeEntryStack
162 //
163 // Specialization of SignatureIterator - in order to set up first stack frame
164 //
165 class ComputeEntryStack : public SignatureIterator {
166 CellTypeState *_effect;
167 int _idx;
168
169 void setup();
170 void set(CellTypeState state) { _effect[_idx++] = state; }
171 int length() { return _idx; };
172
173 friend class SignatureIterator; // so do_parameters_on can call do_type
174 void do_type(BasicType type, bool for_return = false) {
175 if (for_return && type == T_VOID) {
176 set(CellTypeState::bottom);
177 } else if (is_reference_type(type)) {
178 set(CellTypeState::make_slot_ref(_idx));
179 } else {
180 assert(is_java_primitive(type), "");
181 set(CellTypeState::value);
182 if (is_double_word_type(type)) {
183 set(CellTypeState::value);
184 }
185 }
186 }
187
188 public:
189 ComputeEntryStack(Symbol* signature) : SignatureIterator(signature) {};
190
191 // Compute methods
192 int compute_for_parameters(bool is_static, CellTypeState *effect) {
193 _idx = 0;
194 _effect = effect;
195
196 if (!is_static)
197 effect[_idx++] = CellTypeState::make_slot_ref(0);
198
199 do_parameters_on(this);
200
201 return length();
202 };
203
204 int compute_for_returntype(CellTypeState *effect) {
205 _idx = 0;
206 _effect = effect;
207 do_type(return_type(), true);
208 set(CellTypeState::bottom); // Always terminate with a bottom state, so ppush works
209
210 return length();
211 }
212 };
213
214 //=====================================================================================
215 //
216 // Implementation of RetTable/RetTableEntry
217 //
218 // Contains function to itereate through all bytecodes
219 // and find all return entry points
220 //
221 int RetTable::_init_nof_entries = 10;
222 int RetTableEntry::_init_nof_jsrs = 5;
223
224 RetTableEntry::RetTableEntry(int target, RetTableEntry *next) {
225 _target_bci = target;
226 _jsrs = new GrowableArray<int>(_init_nof_jsrs);
227 _next = next;
228 }
229
230 void RetTableEntry::add_delta(int bci, int delta) {
231 if (_target_bci > bci) _target_bci += delta;
232
233 for (int k = 0; k < _jsrs->length(); k++) {
234 int jsr = _jsrs->at(k);
235 if (jsr > bci) _jsrs->at_put(k, jsr+delta);
236 }
237 }
238
239 void RetTable::compute_ret_table(const methodHandle& method) {
240 BytecodeStream i(method);
241 Bytecodes::Code bytecode;
242
243 while( (bytecode = i.next()) >= 0) {
244 switch (bytecode) {
245 case Bytecodes::_jsr:
246 add_jsr(i.next_bci(), i.dest());
247 break;
248 case Bytecodes::_jsr_w:
249 add_jsr(i.next_bci(), i.dest_w());
250 break;
251 default:
252 break;
253 }
254 }
255 }
256
257 void RetTable::add_jsr(int return_bci, int target_bci) {
258 RetTableEntry* entry = _first;
259
260 // Scan table for entry
261 for (;entry && entry->target_bci() != target_bci; entry = entry->next());
262
263 if (!entry) {
264 // Allocate new entry and put in list
265 entry = new RetTableEntry(target_bci, _first);
266 _first = entry;
267 }
268
269 // Now "entry" is set. Make sure that the entry is initialized
270 // and has room for the new jsr.
271 entry->add_jsr(return_bci);
272 }
273
274 RetTableEntry* RetTable::find_jsrs_for_target(int targBci) {
275 RetTableEntry *cur = _first;
276
277 while(cur) {
278 assert(cur->target_bci() != -1, "sanity check");
279 if (cur->target_bci() == targBci) return cur;
280 cur = cur->next();
281 }
282 ShouldNotReachHere();
283 return nullptr;
284 }
285
286 // The instruction at bci is changing size by "delta". Update the return map.
287 void RetTable::update_ret_table(int bci, int delta) {
288 RetTableEntry *cur = _first;
289 while(cur) {
290 cur->add_delta(bci, delta);
291 cur = cur->next();
292 }
293 }
294
295 //
296 // Celltype state
297 //
298
299 CellTypeState CellTypeState::bottom = CellTypeState::make_bottom();
300 CellTypeState CellTypeState::uninit = CellTypeState::make_any(uninit_value);
301 CellTypeState CellTypeState::ref = CellTypeState::make_any(ref_conflict);
302 CellTypeState CellTypeState::value = CellTypeState::make_any(val_value);
303 CellTypeState CellTypeState::refUninit = CellTypeState::make_any(ref_conflict | uninit_value);
304 CellTypeState CellTypeState::top = CellTypeState::make_top();
305 CellTypeState CellTypeState::addr = CellTypeState::make_any(addr_conflict);
306
307 // Commonly used constants
308 static CellTypeState epsilonCTS[1] = { CellTypeState::bottom };
309 static CellTypeState refCTS = CellTypeState::ref;
310 static CellTypeState valCTS = CellTypeState::value;
311 static CellTypeState vCTS[2] = { CellTypeState::value, CellTypeState::bottom };
312 static CellTypeState rCTS[2] = { CellTypeState::ref, CellTypeState::bottom };
313 static CellTypeState rrCTS[3] = { CellTypeState::ref, CellTypeState::ref, CellTypeState::bottom };
314 static CellTypeState vrCTS[3] = { CellTypeState::value, CellTypeState::ref, CellTypeState::bottom };
315 static CellTypeState vvCTS[3] = { CellTypeState::value, CellTypeState::value, CellTypeState::bottom };
316 static CellTypeState rvrCTS[4] = { CellTypeState::ref, CellTypeState::value, CellTypeState::ref, CellTypeState::bottom };
317 static CellTypeState vvrCTS[4] = { CellTypeState::value, CellTypeState::value, CellTypeState::ref, CellTypeState::bottom };
318 static CellTypeState vvvCTS[4] = { CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::bottom };
319 static CellTypeState vvvrCTS[5] = { CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::ref, CellTypeState::bottom };
320 static CellTypeState vvvvCTS[5] = { CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::bottom };
321
322 char CellTypeState::to_char() const {
323 if (can_be_reference()) {
324 if (can_be_value() || can_be_address())
325 return '#'; // Conflict that needs to be rewritten
326 else
327 return 'r';
328 } else if (can_be_value())
329 return 'v';
330 else if (can_be_address())
331 return 'p';
332 else if (can_be_uninit())
333 return ' ';
334 else
335 return '@';
336 }
337
338
339 // Print a detailed CellTypeState. Indicate all bits that are set. If
340 // the CellTypeState represents an address or a reference, print the
341 // value of the additional information.
342 void CellTypeState::print(outputStream *os) {
343 if (can_be_address()) {
344 os->print("(p");
345 } else {
346 os->print("( ");
347 }
348 if (can_be_reference()) {
349 os->print("r");
350 } else {
351 os->print(" ");
352 }
353 if (can_be_value()) {
354 os->print("v");
355 } else {
356 os->print(" ");
357 }
358 if (can_be_uninit()) {
359 os->print("u|");
360 } else {
361 os->print(" |");
362 }
363 if (is_info_top()) {
364 os->print("Top)");
365 } else if (is_info_bottom()) {
366 os->print("Bot)");
367 } else {
368 if (is_reference()) {
369 int info = get_info();
370 int data = info & ~(ref_not_lock_bit | ref_slot_bit);
371 if (info & ref_not_lock_bit) {
372 // Not a monitor lock reference.
373 if (info & ref_slot_bit) {
374 // slot
375 os->print("slot%d)", data);
376 } else {
377 // line
378 os->print("line%d)", data);
379 }
380 } else {
381 // lock
382 os->print("lock%d)", data);
383 }
384 } else {
385 os->print("%d)", get_info());
386 }
387 }
388 }
389
390 //
391 // Basicblock handling methods
392 //
393
394 void GenerateOopMap::initialize_bb() {
395 _gc_points = 0;
396 _bb_count = 0;
397 _bb_hdr_bits.reinitialize(method()->code_size());
398 }
399
400 void GenerateOopMap::bb_mark_fct(GenerateOopMap *c, int bci, int *data) {
401 assert(bci>= 0 && bci < c->method()->code_size(), "index out of bounds");
402 if (c->is_bb_header(bci))
403 return;
404
405 if (TraceNewOopMapGeneration) {
406 tty->print_cr("Basicblock#%d begins at: %d", c->_bb_count, bci);
407 }
408 c->set_bbmark_bit(bci);
409 c->_bb_count++;
410 }
411
412
413 void GenerateOopMap::mark_bbheaders_and_count_gc_points() {
414 initialize_bb();
415
416 bool fellThrough = false; // False to get first BB marked.
417
418 // First mark all exception handlers as start of a basic-block
419 ExceptionTable excps(method());
420 for(int i = 0; i < excps.length(); i ++) {
421 bb_mark_fct(this, excps.handler_pc(i), nullptr);
422 }
423
424 // Then iterate through the code
425 BytecodeStream bcs(_method);
426 Bytecodes::Code bytecode;
427
428 while( (bytecode = bcs.next()) >= 0) {
429 int bci = bcs.bci();
430
431 if (!fellThrough)
432 bb_mark_fct(this, bci, nullptr);
433
434 fellThrough = jump_targets_do(&bcs, &GenerateOopMap::bb_mark_fct, nullptr);
435
436 /* We will also mark successors of jsr's as basic block headers. */
437 switch (bytecode) {
438 case Bytecodes::_jsr:
439 case Bytecodes::_jsr_w:
440 assert(!fellThrough, "should not happen");
441 // If this is the last bytecode, there is no successor to mark
442 if (bci + Bytecodes::length_for(bytecode) < method()->code_size()) {
443 bb_mark_fct(this, bci + Bytecodes::length_for(bytecode), nullptr);
444 }
445 break;
446 default:
447 break;
448 }
449
450 if (possible_gc_point(&bcs))
451 _gc_points++;
452 }
453 }
454
455 void GenerateOopMap::set_bbmark_bit(int bci) {
456 _bb_hdr_bits.at_put(bci, true);
457 }
458
459 void GenerateOopMap::reachable_basicblock(GenerateOopMap *c, int bci, int *data) {
460 assert(bci>= 0 && bci < c->method()->code_size(), "index out of bounds");
461 BasicBlock* bb = c->get_basic_block_at(bci);
462 if (bb->is_dead()) {
463 bb->mark_as_alive();
464 *data = 1; // Mark basicblock as changed
465 }
466 }
467
468
469 void GenerateOopMap::mark_reachable_code() {
470 int change = 1; // int to get function pointers to work
471
472 // Mark entry basic block as alive and all exception handlers
473 _basic_blocks[0].mark_as_alive();
474 ExceptionTable excps(method());
475 for(int i = 0; i < excps.length(); i++) {
476 BasicBlock *bb = get_basic_block_at(excps.handler_pc(i));
477 // If block is not already alive (due to multiple exception handlers to same bb), then
478 // make it alive
479 if (bb->is_dead()) bb->mark_as_alive();
480 }
481
482 BytecodeStream bcs(_method);
483
484 // Iterate through all basic blocks until we reach a fixpoint
485 while (change) {
486 change = 0;
487
488 for (int i = 0; i < _bb_count; i++) {
489 BasicBlock *bb = &_basic_blocks[i];
490 if (bb->is_alive()) {
491 // Position bytecodestream at last bytecode in basicblock
492 bcs.set_start(bb->_end_bci);
493 bcs.next();
494 Bytecodes::Code bytecode = bcs.code();
495 int bci = bcs.bci();
496 assert(bci == bb->_end_bci, "wrong bci");
497
498 bool fell_through = jump_targets_do(&bcs, &GenerateOopMap::reachable_basicblock, &change);
499
500 // We will also mark successors of jsr's as alive.
501 switch (bytecode) {
502 case Bytecodes::_jsr:
503 case Bytecodes::_jsr_w:
504 assert(!fell_through, "should not happen");
505 // If this is the last bytecode, there is no successor to mark
506 if (bci + Bytecodes::length_for(bytecode) < method()->code_size()) {
507 reachable_basicblock(this, bci + Bytecodes::length_for(bytecode), &change);
508 }
509 break;
510 default:
511 break;
512 }
513 if (fell_through) {
514 // Mark successor as alive
515 if (bb[1].is_dead()) {
516 bb[1].mark_as_alive();
517 change = 1;
518 }
519 }
520 }
521 }
522 }
523 }
524
525 /* If the current instruction in "c" has no effect on control flow,
526 returns "true". Otherwise, calls "jmpFct" one or more times, with
527 "c", an appropriate "pcDelta", and "data" as arguments, then
528 returns "false". There is one exception: if the current
529 instruction is a "ret", returns "false" without calling "jmpFct".
530 Arrangements for tracking the control flow of a "ret" must be made
531 externally. */
532 bool GenerateOopMap::jump_targets_do(BytecodeStream *bcs, jmpFct_t jmpFct, int *data) {
533 int bci = bcs->bci();
534
535 switch (bcs->code()) {
536 case Bytecodes::_ifeq:
537 case Bytecodes::_ifne:
538 case Bytecodes::_iflt:
539 case Bytecodes::_ifge:
540 case Bytecodes::_ifgt:
541 case Bytecodes::_ifle:
542 case Bytecodes::_if_icmpeq:
543 case Bytecodes::_if_icmpne:
544 case Bytecodes::_if_icmplt:
545 case Bytecodes::_if_icmpge:
546 case Bytecodes::_if_icmpgt:
547 case Bytecodes::_if_icmple:
548 case Bytecodes::_if_acmpeq:
549 case Bytecodes::_if_acmpne:
550 case Bytecodes::_ifnull:
551 case Bytecodes::_ifnonnull:
552 (*jmpFct)(this, bcs->dest(), data);
553 // Class files verified by the old verifier can have a conditional branch
554 // as their last bytecode, provided the conditional branch is unreachable
555 // during execution. Check if this instruction is the method's last bytecode
556 // and, if so, don't call the jmpFct.
557 if (bci + 3 < method()->code_size()) {
558 (*jmpFct)(this, bci + 3, data);
559 }
560 break;
561
562 case Bytecodes::_goto:
563 (*jmpFct)(this, bcs->dest(), data);
564 break;
565 case Bytecodes::_goto_w:
566 (*jmpFct)(this, bcs->dest_w(), data);
567 break;
568 case Bytecodes::_tableswitch:
569 { Bytecode_tableswitch tableswitch(method(), bcs->bcp());
570 int len = tableswitch.length();
571
572 (*jmpFct)(this, bci + tableswitch.default_offset(), data); /* Default. jump address */
573 while (--len >= 0) {
574 (*jmpFct)(this, bci + tableswitch.dest_offset_at(len), data);
575 }
576 break;
577 }
578
579 case Bytecodes::_lookupswitch:
580 { Bytecode_lookupswitch lookupswitch(method(), bcs->bcp());
581 int npairs = lookupswitch.number_of_pairs();
582 (*jmpFct)(this, bci + lookupswitch.default_offset(), data); /* Default. */
583 while(--npairs >= 0) {
584 LookupswitchPair pair = lookupswitch.pair_at(npairs);
585 (*jmpFct)(this, bci + pair.offset(), data);
586 }
587 break;
588 }
589 case Bytecodes::_jsr:
590 assert(bcs->is_wide()==false, "sanity check");
591 (*jmpFct)(this, bcs->dest(), data);
592 break;
593 case Bytecodes::_jsr_w:
594 (*jmpFct)(this, bcs->dest_w(), data);
595 break;
596 case Bytecodes::_wide:
597 ShouldNotReachHere();
598 return true;
599 break;
600 case Bytecodes::_athrow:
601 case Bytecodes::_ireturn:
602 case Bytecodes::_lreturn:
603 case Bytecodes::_freturn:
604 case Bytecodes::_dreturn:
605 case Bytecodes::_areturn:
606 case Bytecodes::_return:
607 case Bytecodes::_ret:
608 break;
609 default:
610 return true;
611 }
612 return false;
613 }
614
615 /* Requires "pc" to be the head of a basic block; returns that basic
616 block. */
617 BasicBlock *GenerateOopMap::get_basic_block_at(int bci) const {
618 BasicBlock* bb = get_basic_block_containing(bci);
619 assert(bb->_bci == bci, "should have found BB");
620 return bb;
621 }
622
623 // Requires "pc" to be the start of an instruction; returns the basic
624 // block containing that instruction. */
625 BasicBlock *GenerateOopMap::get_basic_block_containing(int bci) const {
626 BasicBlock *bbs = _basic_blocks;
627 int lo = 0, hi = _bb_count - 1;
628
629 while (lo <= hi) {
630 int m = (lo + hi) / 2;
631 int mbci = bbs[m]._bci;
632 int nbci;
633
634 if ( m == _bb_count-1) {
635 assert( bci >= mbci && bci < method()->code_size(), "sanity check failed");
636 return bbs+m;
637 } else {
638 nbci = bbs[m+1]._bci;
639 }
640
641 if ( mbci <= bci && bci < nbci) {
642 return bbs+m;
643 } else if (mbci < bci) {
644 lo = m + 1;
645 } else {
646 assert(mbci > bci, "sanity check");
647 hi = m - 1;
648 }
649 }
650
651 fatal("should have found BB");
652 return nullptr;
653 }
654
655 void GenerateOopMap::restore_state(BasicBlock *bb)
656 {
657 memcpy(_state, bb->_state, _state_len*sizeof(CellTypeState));
658 _stack_top = bb->_stack_top;
659 _monitor_top = bb->_monitor_top;
660 }
661
662 int GenerateOopMap::next_bb_start_pc(BasicBlock *bb) {
663 intptr_t bbNum = bb - _basic_blocks + 1;
664 if (bbNum == _bb_count)
665 return method()->code_size();
666
667 return _basic_blocks[bbNum]._bci;
668 }
669
670 //
671 // CellType handling methods
672 //
673
674 // Allocate memory and throw LinkageError if failure.
675 #define ALLOC_RESOURCE_ARRAY(var, type, count) \
676 var = NEW_RESOURCE_ARRAY_RETURN_NULL(type, count); \
677 if (var == nullptr) { \
678 report_error("Cannot reserve enough memory to analyze this method"); \
679 return; \
680 }
681
682
683 void GenerateOopMap::init_state() {
684 _state_len = _max_locals + _max_stack + _max_monitors;
685 ALLOC_RESOURCE_ARRAY(_state, CellTypeState, _state_len);
686 memset(_state, 0, _state_len * sizeof(CellTypeState));
687 int count = MAX3(_max_locals, _max_stack, _max_monitors) + 1/*for null terminator char */;
688 ALLOC_RESOURCE_ARRAY(_state_vec_buf, char, count);
689 }
690
691 void GenerateOopMap::make_context_uninitialized() {
692 CellTypeState* vs = vars();
693
694 for (int i = 0; i < _max_locals; i++)
695 vs[i] = CellTypeState::uninit;
696
697 _stack_top = 0;
698 _monitor_top = 0;
699 }
700
701 int GenerateOopMap::methodsig_to_effect(Symbol* signature, bool is_static, CellTypeState* effect) {
702 ComputeEntryStack ces(signature);
703 return ces.compute_for_parameters(is_static, effect);
704 }
705
706 // Return result of merging cts1 and cts2.
707 CellTypeState CellTypeState::merge(CellTypeState cts, int slot) const {
708 CellTypeState result;
709
710 assert(!is_bottom() && !cts.is_bottom(),
711 "merge of bottom values is handled elsewhere");
712
713 result._state = _state | cts._state;
714
715 // If the top bit is set, we don't need to do any more work.
716 if (!result.is_info_top()) {
717 assert((result.can_be_address() || result.can_be_reference()),
718 "only addresses and references have non-top info");
719
720 if (!equal(cts)) {
721 // The two values being merged are different. Raise to top.
722 if (result.is_reference()) {
723 result = CellTypeState::make_slot_ref(slot);
724 } else {
725 result._state |= info_conflict;
726 }
727 }
728 }
729 assert(result.is_valid_state(), "checking that CTS merge maintains legal state");
730
731 return result;
732 }
733
734 // Merge the variable state for locals and stack from cts into bbts.
735 bool GenerateOopMap::merge_local_state_vectors(CellTypeState* cts,
736 CellTypeState* bbts) {
737 int i;
738 int len = _max_locals + _stack_top;
739 bool change = false;
740
741 for (i = len - 1; i >= 0; i--) {
742 CellTypeState v = cts[i].merge(bbts[i], i);
743 change = change || !v.equal(bbts[i]);
744 bbts[i] = v;
745 }
746
747 return change;
748 }
749
750 // Merge the monitor stack state from cts into bbts.
751 bool GenerateOopMap::merge_monitor_state_vectors(CellTypeState* cts,
752 CellTypeState* bbts) {
753 bool change = false;
754 if (_max_monitors > 0 && _monitor_top != bad_monitors) {
755 // If there are no monitors in the program, or there has been
756 // a monitor matching error before this point in the program,
757 // then we do not merge in the monitor state.
758
759 int base = _max_locals + _max_stack;
760 int len = base + _monitor_top;
761 for (int i = len - 1; i >= base; i--) {
762 CellTypeState v = cts[i].merge(bbts[i], i);
763
764 // Can we prove that, when there has been a change, it will already
765 // have been detected at this point? That would make this equal
766 // check here unnecessary.
767 change = change || !v.equal(bbts[i]);
768 bbts[i] = v;
769 }
770 }
771
772 return change;
773 }
774
775 void GenerateOopMap::copy_state(CellTypeState *dst, CellTypeState *src) {
776 int len = _max_locals + _stack_top;
777 for (int i = 0; i < len; i++) {
778 if (src[i].is_nonlock_reference()) {
779 dst[i] = CellTypeState::make_slot_ref(i);
780 } else {
781 dst[i] = src[i];
782 }
783 }
784 if (_max_monitors > 0 && _monitor_top != bad_monitors) {
785 int base = _max_locals + _max_stack;
786 len = base + _monitor_top;
787 for (int i = base; i < len; i++) {
788 dst[i] = src[i];
789 }
790 }
791 }
792
793
794 // Merge the states for the current block and the next. As long as a
795 // block is reachable the locals and stack must be merged. If the
796 // stack heights don't match then this is a verification error and
797 // it's impossible to interpret the code. Simultaneously monitor
798 // states are being check to see if they nest statically. If monitor
799 // depths match up then their states are merged. Otherwise the
800 // mismatch is simply recorded and interpretation continues since
801 // monitor matching is purely informational and doesn't say anything
802 // about the correctness of the code.
803 void GenerateOopMap::merge_state_into_bb(BasicBlock *bb) {
804 guarantee(bb != nullptr, "null basicblock");
805 assert(bb->is_alive(), "merging state into a dead basicblock");
806
807 if (_stack_top == bb->_stack_top) {
808 // always merge local state even if monitors don't match.
809 if (merge_local_state_vectors(_state, bb->_state)) {
810 bb->set_changed(true);
811 }
812 if (_monitor_top == bb->_monitor_top) {
813 // monitors still match so continue merging monitor states.
814 if (merge_monitor_state_vectors(_state, bb->_state)) {
815 bb->set_changed(true);
816 }
817 } else {
818 if (log_is_enabled(Info, monitormismatch)) {
819 report_monitor_mismatch("monitor stack height merge conflict");
820 }
821 // When the monitor stacks are not matched, we set _monitor_top to
822 // bad_monitors. This signals that, from here on, the monitor stack cannot
823 // be trusted. In particular, monitorexit bytecodes may throw
824 // exceptions. We mark this block as changed so that the change
825 // propagates properly.
826 bb->_monitor_top = bad_monitors;
827 bb->set_changed(true);
828 _monitor_safe = false;
829 }
830 } else if (!bb->is_reachable()) {
831 // First time we look at this BB
832 copy_state(bb->_state, _state);
833 bb->_stack_top = _stack_top;
834 bb->_monitor_top = _monitor_top;
835 bb->set_changed(true);
836 } else {
837 verify_error("stack height conflict: %d vs. %d", _stack_top, bb->_stack_top);
838 }
839 }
840
841 void GenerateOopMap::merge_state(GenerateOopMap *gom, int bci, int* data) {
842 gom->merge_state_into_bb(gom->get_basic_block_at(bci));
843 }
844
845 void GenerateOopMap::set_var(int localNo, CellTypeState cts) {
846 assert(cts.is_reference() || cts.is_value() || cts.is_address(),
847 "wrong celltypestate");
848 if (localNo < 0 || localNo > _max_locals) {
849 verify_error("variable write error: r%d", localNo);
850 return;
851 }
852 vars()[localNo] = cts;
853 }
854
855 CellTypeState GenerateOopMap::get_var(int localNo) {
856 assert(localNo < _max_locals + _nof_refval_conflicts, "variable read error");
857 if (localNo < 0 || localNo > _max_locals) {
858 verify_error("variable read error: r%d", localNo);
859 return valCTS; // just to pick something;
860 }
861 return vars()[localNo];
862 }
863
864 CellTypeState GenerateOopMap::pop() {
865 if ( _stack_top <= 0) {
866 verify_error("stack underflow");
867 return valCTS; // just to pick something
868 }
869 return stack()[--_stack_top];
870 }
871
872 void GenerateOopMap::push(CellTypeState cts) {
873 if ( _stack_top >= _max_stack) {
874 verify_error("stack overflow");
875 return;
876 }
877 stack()[_stack_top++] = cts;
878 }
879
880 CellTypeState GenerateOopMap::monitor_pop() {
881 assert(_monitor_top != bad_monitors, "monitor_pop called on error monitor stack");
882 if (_monitor_top == 0) {
883 // We have detected a pop of an empty monitor stack.
884 _monitor_safe = false;
885 _monitor_top = bad_monitors;
886
887 if (log_is_enabled(Info, monitormismatch)) {
888 report_monitor_mismatch("monitor stack underflow");
889 }
890 return CellTypeState::ref; // just to keep the analysis going.
891 }
892 return monitors()[--_monitor_top];
893 }
894
895 void GenerateOopMap::monitor_push(CellTypeState cts) {
896 assert(_monitor_top != bad_monitors, "monitor_push called on error monitor stack");
897 if (_monitor_top >= _max_monitors) {
898 // Some monitorenter is being executed more than once.
899 // This means that the monitor stack cannot be simulated.
900 _monitor_safe = false;
901 _monitor_top = bad_monitors;
902
903 if (log_is_enabled(Info, monitormismatch)) {
904 report_monitor_mismatch("monitor stack overflow");
905 }
906 return;
907 }
908 monitors()[_monitor_top++] = cts;
909 }
910
911 //
912 // Interpretation handling methods
913 //
914
915 void GenerateOopMap::do_interpretation()
916 {
917 // "i" is just for debugging, so we can detect cases where this loop is
918 // iterated more than once.
919 int i = 0;
920 do {
921 #ifndef PRODUCT
922 if (TraceNewOopMapGeneration) {
923 tty->print("\n\nIteration #%d of do_interpretation loop, method:\n", i);
924 method()->print_name(tty);
925 tty->print("\n\n");
926 }
927 #endif
928 _conflict = false;
929 _monitor_safe = true;
930 // init_state is now called from init_basic_blocks. The length of a
931 // state vector cannot be determined until we have made a pass through
932 // the bytecodes counting the possible monitor entries.
933 if (!_got_error) init_basic_blocks();
934 if (!_got_error) setup_method_entry_state();
935 if (!_got_error) interp_all();
936 if (!_got_error) rewrite_refval_conflicts();
937 i++;
938 } while (_conflict && !_got_error);
939 }
940
941 void GenerateOopMap::init_basic_blocks() {
942 // Note: Could consider reserving only the needed space for each BB's state
943 // (entry stack may not be of maximal height for every basic block).
944 // But cumbersome since we don't know the stack heights yet. (Nor the
945 // monitor stack heights...)
946
947 ALLOC_RESOURCE_ARRAY(_basic_blocks, BasicBlock, _bb_count);
948
949 // Make a pass through the bytecodes. Count the number of monitorenters.
950 // This can be used an upper bound on the monitor stack depth in programs
951 // which obey stack discipline with their monitor usage. Initialize the
952 // known information about basic blocks.
953 BytecodeStream j(_method);
954 Bytecodes::Code bytecode;
955
956 int bbNo = 0;
957 int monitor_count = 0;
958 int prev_bci = -1;
959 while( (bytecode = j.next()) >= 0) {
960 if (j.code() == Bytecodes::_monitorenter) {
961 monitor_count++;
962 }
963
964 int bci = j.bci();
965 if (is_bb_header(bci)) {
966 // Initialize the basicblock structure
967 BasicBlock *bb = _basic_blocks + bbNo;
968 bb->_bci = bci;
969 bb->_max_locals = _max_locals;
970 bb->_max_stack = _max_stack;
971 bb->set_changed(false);
972 bb->_stack_top = BasicBlock::_dead_basic_block; // Initialize all basicblocks are dead.
973 bb->_monitor_top = bad_monitors;
974
975 if (bbNo > 0) {
976 _basic_blocks[bbNo - 1]._end_bci = prev_bci;
977 }
978
979 bbNo++;
980 }
981 // Remember previous bci.
982 prev_bci = bci;
983 }
984 // Set
985 _basic_blocks[bbNo-1]._end_bci = prev_bci;
986
987
988 // Check that the correct number of basicblocks was found
989 if (bbNo !=_bb_count) {
990 if (bbNo < _bb_count) {
991 verify_error("jump into the middle of instruction?");
992 return;
993 } else {
994 verify_error("extra basic blocks - should not happen?");
995 return;
996 }
997 }
998
999 _max_monitors = monitor_count;
1000
1001 // Now that we have a bound on the depth of the monitor stack, we can
1002 // initialize the CellTypeState-related information.
1003 init_state();
1004
1005 // We allocate space for all state-vectors for all basicblocks in one huge
1006 // chunk. Then in the next part of the code, we set a pointer in each
1007 // _basic_block that points to each piece.
1008
1009 // The product of bbNo and _state_len can get large if there are lots of
1010 // basic blocks and stack/locals/monitors. Need to check to make sure
1011 // we don't overflow the capacity of a pointer.
1012 if ((unsigned)bbNo > UINTPTR_MAX / sizeof(CellTypeState) / _state_len) {
1013 report_error("The amount of memory required to analyze this method "
1014 "exceeds addressable range");
1015 return;
1016 }
1017
1018 CellTypeState *basicBlockState;
1019 ALLOC_RESOURCE_ARRAY(basicBlockState, CellTypeState, bbNo * _state_len);
1020 memset(basicBlockState, 0, bbNo * _state_len * sizeof(CellTypeState));
1021
1022 // Make a pass over the basicblocks and assign their state vectors.
1023 for (int blockNum=0; blockNum < bbNo; blockNum++) {
1024 BasicBlock *bb = _basic_blocks + blockNum;
1025 bb->_state = basicBlockState + blockNum * _state_len;
1026
1027 #ifdef ASSERT
1028 if (blockNum + 1 < bbNo) {
1029 address bcp = _method->bcp_from(bb->_end_bci);
1030 int bc_len = Bytecodes::java_length_at(_method(), bcp);
1031 assert(bb->_end_bci + bc_len == bb[1]._bci, "unmatched bci info in basicblock");
1032 }
1033 #endif
1034 }
1035 #ifdef ASSERT
1036 { BasicBlock *bb = &_basic_blocks[bbNo-1];
1037 address bcp = _method->bcp_from(bb->_end_bci);
1038 int bc_len = Bytecodes::java_length_at(_method(), bcp);
1039 assert(bb->_end_bci + bc_len == _method->code_size(), "wrong end bci");
1040 }
1041 #endif
1042
1043 // Mark all alive blocks
1044 mark_reachable_code();
1045 }
1046
1047 void GenerateOopMap::setup_method_entry_state() {
1048
1049 // Initialize all locals to 'uninit' and set stack-height to 0
1050 make_context_uninitialized();
1051
1052 // Initialize CellState type of arguments
1053 methodsig_to_effect(method()->signature(), method()->is_static(), vars());
1054
1055 // If some references must be pre-assigned to null, then set that up
1056 initialize_vars();
1057
1058 // This is the start state
1059 merge_state_into_bb(&_basic_blocks[0]);
1060
1061 assert(_basic_blocks[0].changed(), "we are not getting off the ground");
1062 }
1063
1064 // The instruction at bci is changing size by "delta". Update the basic blocks.
1065 void GenerateOopMap::update_basic_blocks(int bci, int delta,
1066 int new_method_size) {
1067 assert(new_method_size >= method()->code_size() + delta,
1068 "new method size is too small");
1069
1070 _bb_hdr_bits.reinitialize(new_method_size);
1071
1072 for(int k = 0; k < _bb_count; k++) {
1073 if (_basic_blocks[k]._bci > bci) {
1074 _basic_blocks[k]._bci += delta;
1075 _basic_blocks[k]._end_bci += delta;
1076 }
1077 _bb_hdr_bits.at_put(_basic_blocks[k]._bci, true);
1078 }
1079 }
1080
1081 //
1082 // Initvars handling
1083 //
1084
1085 void GenerateOopMap::initialize_vars() {
1086 for (int k = 0; k < _init_vars->length(); k++)
1087 _state[_init_vars->at(k)] = CellTypeState::make_slot_ref(k);
1088 }
1089
1090 void GenerateOopMap::add_to_ref_init_set(int localNo) {
1091
1092 if (TraceNewOopMapGeneration)
1093 tty->print_cr("Added init vars: %d", localNo);
1094
1095 // Is it already in the set?
1096 if (_init_vars->contains(localNo) )
1097 return;
1098
1099 _init_vars->append(localNo);
1100 }
1101
1102 //
1103 // Interpreration code
1104 //
1105
1106 void GenerateOopMap::interp_all() {
1107 bool change = true;
1108
1109 while (change && !_got_error) {
1110 change = false;
1111 for (int i = 0; i < _bb_count && !_got_error; i++) {
1112 BasicBlock *bb = &_basic_blocks[i];
1113 if (bb->changed()) {
1114 if (_got_error) return;
1115 change = true;
1116 bb->set_changed(false);
1117 interp_bb(bb);
1118 }
1119 }
1120 }
1121 }
1122
1123 void GenerateOopMap::interp_bb(BasicBlock *bb) {
1124
1125 // We do not want to do anything in case the basic-block has not been initialized. This
1126 // will happen in the case where there is dead-code hang around in a method.
1127 assert(bb->is_reachable(), "should be reachable or deadcode exist");
1128 restore_state(bb);
1129
1130 BytecodeStream itr(_method);
1131
1132 // Set iterator interval to be the current basicblock
1133 int lim_bci = next_bb_start_pc(bb);
1134 itr.set_interval(bb->_bci, lim_bci);
1135 assert(lim_bci != bb->_bci, "must be at least one instruction in a basicblock");
1136 itr.next(); // read first instruction
1137
1138 // Iterates through all bytecodes except the last in a basic block.
1139 // We handle the last one special, since there is controlflow change.
1140 while(itr.next_bci() < lim_bci && !_got_error) {
1141 if (_has_exceptions || _monitor_top != 0) {
1142 // We do not need to interpret the results of exceptional
1143 // continuation from this instruction when the method has no
1144 // exception handlers and the monitor stack is currently
1145 // empty.
1146 do_exception_edge(&itr);
1147 }
1148 interp1(&itr);
1149 itr.next();
1150 }
1151
1152 // Handle last instruction.
1153 if (!_got_error) {
1154 assert(itr.next_bci() == lim_bci, "must point to end");
1155 if (_has_exceptions || _monitor_top != 0) {
1156 do_exception_edge(&itr);
1157 }
1158 interp1(&itr);
1159
1160 bool fall_through = jump_targets_do(&itr, GenerateOopMap::merge_state, nullptr);
1161 if (_got_error) return;
1162
1163 if (itr.code() == Bytecodes::_ret) {
1164 assert(!fall_through, "cannot be set if ret instruction");
1165 // Automatically handles 'wide' ret indices
1166 ret_jump_targets_do(&itr, GenerateOopMap::merge_state, itr.get_index(), nullptr);
1167 } else if (fall_through) {
1168 // Hit end of BB, but the instr. was a fall-through instruction,
1169 // so perform transition as if the BB ended in a "jump".
1170 if (lim_bci != bb[1]._bci) {
1171 verify_error("bytecodes fell through last instruction");
1172 return;
1173 }
1174 merge_state_into_bb(bb + 1);
1175 }
1176 }
1177 }
1178
1179 void GenerateOopMap::do_exception_edge(BytecodeStream* itr) {
1180 // Only check exception edge, if bytecode can trap
1181 if (!Bytecodes::can_trap(itr->code())) return;
1182 switch (itr->code()) {
1183 case Bytecodes::_aload_0:
1184 // These bytecodes can trap for rewriting. We need to assume that
1185 // they do not throw exceptions to make the monitor analysis work.
1186 return;
1187
1188 case Bytecodes::_ireturn:
1189 case Bytecodes::_lreturn:
1190 case Bytecodes::_freturn:
1191 case Bytecodes::_dreturn:
1192 case Bytecodes::_areturn:
1193 case Bytecodes::_return:
1194 // If the monitor stack height is not zero when we leave the method,
1195 // then we are either exiting with a non-empty stack or we have
1196 // found monitor trouble earlier in our analysis. In either case,
1197 // assume an exception could be taken here.
1198 if (_monitor_top == 0) {
1199 return;
1200 }
1201 break;
1202
1203 case Bytecodes::_monitorexit:
1204 // If the monitor stack height is bad_monitors, then we have detected a
1205 // monitor matching problem earlier in the analysis. If the
1206 // monitor stack height is 0, we are about to pop a monitor
1207 // off of an empty stack. In either case, the bytecode
1208 // could throw an exception.
1209 if (_monitor_top != bad_monitors && _monitor_top != 0) {
1210 return;
1211 }
1212 break;
1213
1214 default:
1215 break;
1216 }
1217
1218 if (_has_exceptions) {
1219 int bci = itr->bci();
1220 ExceptionTable exct(method());
1221 for(int i = 0; i< exct.length(); i++) {
1222 int start_pc = exct.start_pc(i);
1223 int end_pc = exct.end_pc(i);
1224 int handler_pc = exct.handler_pc(i);
1225 int catch_type = exct.catch_type_index(i);
1226
1227 if (start_pc <= bci && bci < end_pc) {
1228 BasicBlock *excBB = get_basic_block_at(handler_pc);
1229 guarantee(excBB != nullptr, "no basic block for exception");
1230 CellTypeState *excStk = excBB->stack();
1231 CellTypeState *cOpStck = stack();
1232 CellTypeState cOpStck_0 = cOpStck[0];
1233 int cOpStackTop = _stack_top;
1234
1235 // Exception stacks are always the same.
1236 assert(method()->max_stack() > 0, "sanity check");
1237
1238 // We remembered the size and first element of "cOpStck"
1239 // above; now we temporarily set them to the appropriate
1240 // values for an exception handler. */
1241 cOpStck[0] = CellTypeState::make_slot_ref(_max_locals);
1242 _stack_top = 1;
1243
1244 merge_state_into_bb(excBB);
1245
1246 // Now undo the temporary change.
1247 cOpStck[0] = cOpStck_0;
1248 _stack_top = cOpStackTop;
1249
1250 // If this is a "catch all" handler, then we do not need to
1251 // consider any additional handlers.
1252 if (catch_type == 0) {
1253 return;
1254 }
1255 }
1256 }
1257 }
1258
1259 // It is possible that none of the exception handlers would have caught
1260 // the exception. In this case, we will exit the method. We must
1261 // ensure that the monitor stack is empty in this case.
1262 if (_monitor_top == 0) {
1263 return;
1264 }
1265
1266 // We pessimistically assume that this exception can escape the
1267 // method. (It is possible that it will always be caught, but
1268 // we don't care to analyse the types of the catch clauses.)
1269
1270 // We don't set _monitor_top to bad_monitors because there are no successors
1271 // to this exceptional exit.
1272
1273 if (log_is_enabled(Info, monitormismatch) && _monitor_safe) {
1274 // We check _monitor_safe so that we only report the first mismatched
1275 // exceptional exit.
1276 report_monitor_mismatch("non-empty monitor stack at exceptional exit");
1277 }
1278 _monitor_safe = false;
1279
1280 }
1281
1282 void GenerateOopMap::report_monitor_mismatch(const char *msg) {
1283 ResourceMark rm;
1284 LogStream ls(Log(monitormismatch)::info());
1285 ls.print("Monitor mismatch in method ");
1286 method()->print_short_name(&ls);
1287 ls.print_cr(": %s", msg);
1288 }
1289
1290 void GenerateOopMap::print_states(outputStream *os,
1291 CellTypeState* vec, int num) {
1292 for (int i = 0; i < num; i++) {
1293 vec[i].print(tty);
1294 }
1295 }
1296
1297 // Print the state values at the current bytecode.
1298 void GenerateOopMap::print_current_state(outputStream *os,
1299 BytecodeStream *currentBC,
1300 bool detailed) {
1301 if (detailed) {
1302 os->print(" %4d vars = ", currentBC->bci());
1303 print_states(os, vars(), _max_locals);
1304 os->print(" %s", Bytecodes::name(currentBC->code()));
1305 } else {
1306 os->print(" %4d vars = '%s' ", currentBC->bci(), state_vec_to_string(vars(), _max_locals));
1307 os->print(" stack = '%s' ", state_vec_to_string(stack(), _stack_top));
1308 if (_monitor_top != bad_monitors) {
1309 os->print(" monitors = '%s' \t%s", state_vec_to_string(monitors(), _monitor_top), Bytecodes::name(currentBC->code()));
1310 } else {
1311 os->print(" [bad monitor stack]");
1312 }
1313 }
1314
1315 switch(currentBC->code()) {
1316 case Bytecodes::_invokevirtual:
1317 case Bytecodes::_invokespecial:
1318 case Bytecodes::_invokestatic:
1319 case Bytecodes::_invokedynamic:
1320 case Bytecodes::_invokeinterface: {
1321 int idx = currentBC->has_index_u4() ? currentBC->get_index_u4() : currentBC->get_index_u2();
1322 ConstantPool* cp = method()->constants();
1323 int nameAndTypeIdx = cp->name_and_type_ref_index_at(idx, currentBC->code());
1324 int signatureIdx = cp->signature_ref_index_at(nameAndTypeIdx);
1325 Symbol* signature = cp->symbol_at(signatureIdx);
1326 os->print("%s", signature->as_C_string());
1327 }
1328 default:
1329 break;
1330 }
1331
1332 if (detailed) {
1333 os->cr();
1334 os->print(" stack = ");
1335 print_states(os, stack(), _stack_top);
1336 os->cr();
1337 if (_monitor_top != bad_monitors) {
1338 os->print(" monitors = ");
1339 print_states(os, monitors(), _monitor_top);
1340 } else {
1341 os->print(" [bad monitor stack]");
1342 }
1343 }
1344
1345 os->cr();
1346 }
1347
1348 // Sets the current state to be the state after executing the
1349 // current instruction, starting in the current state.
1350 void GenerateOopMap::interp1(BytecodeStream *itr) {
1351 if (TraceNewOopMapGeneration) {
1352 print_current_state(tty, itr, TraceNewOopMapGenerationDetailed);
1353 }
1354
1355 // Should we report the results? Result is reported *before* the instruction at the current bci is executed.
1356 // However, not for calls. For calls we do not want to include the arguments, so we postpone the reporting until
1357 // they have been popped (in method ppl).
1358 if (_report_result == true) {
1359 switch(itr->code()) {
1360 case Bytecodes::_invokevirtual:
1361 case Bytecodes::_invokespecial:
1362 case Bytecodes::_invokestatic:
1363 case Bytecodes::_invokedynamic:
1364 case Bytecodes::_invokeinterface:
1365 _itr_send = itr;
1366 _report_result_for_send = true;
1367 break;
1368 default:
1369 fill_stackmap_for_opcodes(itr, vars(), stack(), _stack_top);
1370 break;
1371 }
1372 }
1373
1374 // abstract interpretation of current opcode
1375 switch(itr->code()) {
1376 case Bytecodes::_nop: break;
1377 case Bytecodes::_goto: break;
1378 case Bytecodes::_goto_w: break;
1379 case Bytecodes::_iinc: break;
1380 case Bytecodes::_return: do_return_monitor_check();
1381 break;
1382
1383 case Bytecodes::_aconst_null:
1384 case Bytecodes::_new: ppush1(CellTypeState::make_line_ref(itr->bci()));
1385 break;
1386
1387 case Bytecodes::_iconst_m1:
1388 case Bytecodes::_iconst_0:
1389 case Bytecodes::_iconst_1:
1390 case Bytecodes::_iconst_2:
1391 case Bytecodes::_iconst_3:
1392 case Bytecodes::_iconst_4:
1393 case Bytecodes::_iconst_5:
1394 case Bytecodes::_fconst_0:
1395 case Bytecodes::_fconst_1:
1396 case Bytecodes::_fconst_2:
1397 case Bytecodes::_bipush:
1398 case Bytecodes::_sipush: ppush1(valCTS); break;
1399
1400 case Bytecodes::_lconst_0:
1401 case Bytecodes::_lconst_1:
1402 case Bytecodes::_dconst_0:
1403 case Bytecodes::_dconst_1: ppush(vvCTS); break;
1404
1405 case Bytecodes::_ldc2_w: ppush(vvCTS); break;
1406
1407 case Bytecodes::_ldc: // fall through:
1408 case Bytecodes::_ldc_w: do_ldc(itr->bci()); break;
1409
1410 case Bytecodes::_iload:
1411 case Bytecodes::_fload: ppload(vCTS, itr->get_index()); break;
1412
1413 case Bytecodes::_lload:
1414 case Bytecodes::_dload: ppload(vvCTS,itr->get_index()); break;
1415
1416 case Bytecodes::_aload: ppload(rCTS, itr->get_index()); break;
1417
1418 case Bytecodes::_iload_0:
1419 case Bytecodes::_fload_0: ppload(vCTS, 0); break;
1420 case Bytecodes::_iload_1:
1421 case Bytecodes::_fload_1: ppload(vCTS, 1); break;
1422 case Bytecodes::_iload_2:
1423 case Bytecodes::_fload_2: ppload(vCTS, 2); break;
1424 case Bytecodes::_iload_3:
1425 case Bytecodes::_fload_3: ppload(vCTS, 3); break;
1426
1427 case Bytecodes::_lload_0:
1428 case Bytecodes::_dload_0: ppload(vvCTS, 0); break;
1429 case Bytecodes::_lload_1:
1430 case Bytecodes::_dload_1: ppload(vvCTS, 1); break;
1431 case Bytecodes::_lload_2:
1432 case Bytecodes::_dload_2: ppload(vvCTS, 2); break;
1433 case Bytecodes::_lload_3:
1434 case Bytecodes::_dload_3: ppload(vvCTS, 3); break;
1435
1436 case Bytecodes::_aload_0: ppload(rCTS, 0); break;
1437 case Bytecodes::_aload_1: ppload(rCTS, 1); break;
1438 case Bytecodes::_aload_2: ppload(rCTS, 2); break;
1439 case Bytecodes::_aload_3: ppload(rCTS, 3); break;
1440
1441 case Bytecodes::_iaload:
1442 case Bytecodes::_faload:
1443 case Bytecodes::_baload:
1444 case Bytecodes::_caload:
1445 case Bytecodes::_saload: pp(vrCTS, vCTS); break;
1446
1447 case Bytecodes::_laload: pp(vrCTS, vvCTS); break;
1448 case Bytecodes::_daload: pp(vrCTS, vvCTS); break;
1449
1450 case Bytecodes::_aaload: pp_new_ref(vrCTS, itr->bci()); break;
1451
1452 case Bytecodes::_istore:
1453 case Bytecodes::_fstore: ppstore(vCTS, itr->get_index()); break;
1454
1455 case Bytecodes::_lstore:
1456 case Bytecodes::_dstore: ppstore(vvCTS, itr->get_index()); break;
1457
1458 case Bytecodes::_astore: do_astore(itr->get_index()); break;
1459
1460 case Bytecodes::_istore_0:
1461 case Bytecodes::_fstore_0: ppstore(vCTS, 0); break;
1462 case Bytecodes::_istore_1:
1463 case Bytecodes::_fstore_1: ppstore(vCTS, 1); break;
1464 case Bytecodes::_istore_2:
1465 case Bytecodes::_fstore_2: ppstore(vCTS, 2); break;
1466 case Bytecodes::_istore_3:
1467 case Bytecodes::_fstore_3: ppstore(vCTS, 3); break;
1468
1469 case Bytecodes::_lstore_0:
1470 case Bytecodes::_dstore_0: ppstore(vvCTS, 0); break;
1471 case Bytecodes::_lstore_1:
1472 case Bytecodes::_dstore_1: ppstore(vvCTS, 1); break;
1473 case Bytecodes::_lstore_2:
1474 case Bytecodes::_dstore_2: ppstore(vvCTS, 2); break;
1475 case Bytecodes::_lstore_3:
1476 case Bytecodes::_dstore_3: ppstore(vvCTS, 3); break;
1477
1478 case Bytecodes::_astore_0: do_astore(0); break;
1479 case Bytecodes::_astore_1: do_astore(1); break;
1480 case Bytecodes::_astore_2: do_astore(2); break;
1481 case Bytecodes::_astore_3: do_astore(3); break;
1482
1483 case Bytecodes::_iastore:
1484 case Bytecodes::_fastore:
1485 case Bytecodes::_bastore:
1486 case Bytecodes::_castore:
1487 case Bytecodes::_sastore: ppop(vvrCTS); break;
1488 case Bytecodes::_lastore:
1489 case Bytecodes::_dastore: ppop(vvvrCTS); break;
1490 case Bytecodes::_aastore: ppop(rvrCTS); break;
1491
1492 case Bytecodes::_pop: ppop_any(1); break;
1493 case Bytecodes::_pop2: ppop_any(2); break;
1494
1495 case Bytecodes::_dup: ppdupswap(1, "11"); break;
1496 case Bytecodes::_dup_x1: ppdupswap(2, "121"); break;
1497 case Bytecodes::_dup_x2: ppdupswap(3, "1321"); break;
1498 case Bytecodes::_dup2: ppdupswap(2, "2121"); break;
1499 case Bytecodes::_dup2_x1: ppdupswap(3, "21321"); break;
1500 case Bytecodes::_dup2_x2: ppdupswap(4, "214321"); break;
1501 case Bytecodes::_swap: ppdupswap(2, "12"); break;
1502
1503 case Bytecodes::_iadd:
1504 case Bytecodes::_fadd:
1505 case Bytecodes::_isub:
1506 case Bytecodes::_fsub:
1507 case Bytecodes::_imul:
1508 case Bytecodes::_fmul:
1509 case Bytecodes::_idiv:
1510 case Bytecodes::_fdiv:
1511 case Bytecodes::_irem:
1512 case Bytecodes::_frem:
1513 case Bytecodes::_ishl:
1514 case Bytecodes::_ishr:
1515 case Bytecodes::_iushr:
1516 case Bytecodes::_iand:
1517 case Bytecodes::_ior:
1518 case Bytecodes::_ixor:
1519 case Bytecodes::_l2f:
1520 case Bytecodes::_l2i:
1521 case Bytecodes::_d2f:
1522 case Bytecodes::_d2i:
1523 case Bytecodes::_fcmpl:
1524 case Bytecodes::_fcmpg: pp(vvCTS, vCTS); break;
1525
1526 case Bytecodes::_ladd:
1527 case Bytecodes::_dadd:
1528 case Bytecodes::_lsub:
1529 case Bytecodes::_dsub:
1530 case Bytecodes::_lmul:
1531 case Bytecodes::_dmul:
1532 case Bytecodes::_ldiv:
1533 case Bytecodes::_ddiv:
1534 case Bytecodes::_lrem:
1535 case Bytecodes::_drem:
1536 case Bytecodes::_land:
1537 case Bytecodes::_lor:
1538 case Bytecodes::_lxor: pp(vvvvCTS, vvCTS); break;
1539
1540 case Bytecodes::_ineg:
1541 case Bytecodes::_fneg:
1542 case Bytecodes::_i2f:
1543 case Bytecodes::_f2i:
1544 case Bytecodes::_i2c:
1545 case Bytecodes::_i2s:
1546 case Bytecodes::_i2b: pp(vCTS, vCTS); break;
1547
1548 case Bytecodes::_lneg:
1549 case Bytecodes::_dneg:
1550 case Bytecodes::_l2d:
1551 case Bytecodes::_d2l: pp(vvCTS, vvCTS); break;
1552
1553 case Bytecodes::_lshl:
1554 case Bytecodes::_lshr:
1555 case Bytecodes::_lushr: pp(vvvCTS, vvCTS); break;
1556
1557 case Bytecodes::_i2l:
1558 case Bytecodes::_i2d:
1559 case Bytecodes::_f2l:
1560 case Bytecodes::_f2d: pp(vCTS, vvCTS); break;
1561
1562 case Bytecodes::_lcmp: pp(vvvvCTS, vCTS); break;
1563 case Bytecodes::_dcmpl:
1564 case Bytecodes::_dcmpg: pp(vvvvCTS, vCTS); break;
1565
1566 case Bytecodes::_ifeq:
1567 case Bytecodes::_ifne:
1568 case Bytecodes::_iflt:
1569 case Bytecodes::_ifge:
1570 case Bytecodes::_ifgt:
1571 case Bytecodes::_ifle:
1572 case Bytecodes::_tableswitch: ppop1(valCTS);
1573 break;
1574 case Bytecodes::_ireturn:
1575 case Bytecodes::_freturn: do_return_monitor_check();
1576 ppop1(valCTS);
1577 break;
1578 case Bytecodes::_if_icmpeq:
1579 case Bytecodes::_if_icmpne:
1580 case Bytecodes::_if_icmplt:
1581 case Bytecodes::_if_icmpge:
1582 case Bytecodes::_if_icmpgt:
1583 case Bytecodes::_if_icmple: ppop(vvCTS);
1584 break;
1585
1586 case Bytecodes::_lreturn: do_return_monitor_check();
1587 ppop(vvCTS);
1588 break;
1589
1590 case Bytecodes::_dreturn: do_return_monitor_check();
1591 ppop(vvCTS);
1592 break;
1593
1594 case Bytecodes::_if_acmpeq:
1595 case Bytecodes::_if_acmpne: ppop(rrCTS); break;
1596
1597 case Bytecodes::_jsr: do_jsr(itr->dest()); break;
1598 case Bytecodes::_jsr_w: do_jsr(itr->dest_w()); break;
1599
1600 case Bytecodes::_getstatic: do_field(true, true, itr->get_index_u2(), itr->bci(), itr->code()); break;
1601 case Bytecodes::_putstatic: do_field(false, true, itr->get_index_u2(), itr->bci(), itr->code()); break;
1602 case Bytecodes::_getfield: do_field(true, false, itr->get_index_u2(), itr->bci(), itr->code()); break;
1603 case Bytecodes::_putfield: do_field(false, false, itr->get_index_u2(), itr->bci(), itr->code()); break;
1604
1605 case Bytecodes::_invokeinterface:
1606 case Bytecodes::_invokevirtual:
1607 case Bytecodes::_invokespecial: do_method(false, itr->get_index_u2(), itr->bci(), itr->code()); break;
1608 case Bytecodes::_invokestatic: do_method(true , itr->get_index_u2(), itr->bci(), itr->code()); break;
1609 case Bytecodes::_invokedynamic: do_method(true , itr->get_index_u4(), itr->bci(), itr->code()); break;
1610 case Bytecodes::_newarray:
1611 case Bytecodes::_anewarray: pp_new_ref(vCTS, itr->bci()); break;
1612 case Bytecodes::_checkcast: do_checkcast(); break;
1613 case Bytecodes::_arraylength:
1614 case Bytecodes::_instanceof: pp(rCTS, vCTS); break;
1615 case Bytecodes::_monitorenter: do_monitorenter(itr->bci()); break;
1616 case Bytecodes::_monitorexit: do_monitorexit(itr->bci()); break;
1617
1618 case Bytecodes::_athrow: // handled by do_exception_edge() BUT ...
1619 // vlh(apple): do_exception_edge() does not get
1620 // called if method has no exception handlers
1621 if ((!_has_exceptions) && (_monitor_top > 0)) {
1622 _monitor_safe = false;
1623 }
1624 break;
1625
1626 case Bytecodes::_areturn: do_return_monitor_check();
1627 ppop1(refCTS);
1628 break;
1629
1630 case Bytecodes::_ifnull:
1631 case Bytecodes::_ifnonnull: ppop1(refCTS); break;
1632 case Bytecodes::_multianewarray: do_multianewarray(*(itr->bcp()+3), itr->bci()); break;
1633
1634 case Bytecodes::_wide: fatal("Iterator should skip this bytecode"); break;
1635 case Bytecodes::_ret: break;
1636
1637 // Java opcodes
1638 case Bytecodes::_lookupswitch: ppop1(valCTS); break;
1639
1640 default:
1641 tty->print("unexpected opcode: %d\n", itr->code());
1642 ShouldNotReachHere();
1643 break;
1644 }
1645 }
1646
1647 void GenerateOopMap::check_type(CellTypeState expected, CellTypeState actual) {
1648 if (!expected.equal_kind(actual)) {
1649 verify_error("wrong type on stack (found: %c expected: %c)", actual.to_char(), expected.to_char());
1650 }
1651 }
1652
1653 void GenerateOopMap::ppstore(CellTypeState *in, int loc_no) {
1654 while(!(*in).is_bottom()) {
1655 CellTypeState expected =*in++;
1656 CellTypeState actual = pop();
1657 check_type(expected, actual);
1658 assert(loc_no >= 0, "sanity check");
1659 set_var(loc_no++, actual);
1660 }
1661 }
1662
1663 void GenerateOopMap::ppload(CellTypeState *out, int loc_no) {
1664 while(!(*out).is_bottom()) {
1665 CellTypeState out1 = *out++;
1666 CellTypeState vcts = get_var(loc_no);
1667 assert(out1.can_be_reference() || out1.can_be_value(),
1668 "can only load refs. and values.");
1669 if (out1.is_reference()) {
1670 assert(loc_no>=0, "sanity check");
1671 if (!vcts.is_reference()) {
1672 // We were asked to push a reference, but the type of the
1673 // variable can be something else
1674 _conflict = true;
1675 if (vcts.can_be_uninit()) {
1676 // It is a ref-uninit conflict (at least). If there are other
1677 // problems, we'll get them in the next round
1678 add_to_ref_init_set(loc_no);
1679 vcts = out1;
1680 } else {
1681 // It wasn't a ref-uninit conflict. So must be a
1682 // ref-val or ref-pc conflict. Split the variable.
1683 record_refval_conflict(loc_no);
1684 vcts = out1;
1685 }
1686 push(out1); // recover...
1687 } else {
1688 push(vcts); // preserve reference.
1689 }
1690 // Otherwise it is a conflict, but one that verification would
1691 // have caught if illegal. In particular, it can't be a topCTS
1692 // resulting from mergeing two difference pcCTS's since the verifier
1693 // would have rejected any use of such a merge.
1694 } else {
1695 push(out1); // handle val/init conflict
1696 }
1697 loc_no++;
1698 }
1699 }
1700
1701 void GenerateOopMap::ppdupswap(int poplen, const char *out) {
1702 CellTypeState actual[5];
1703 assert(poplen < 5, "this must be less than length of actual vector");
1704
1705 // Pop all arguments.
1706 for (int i = 0; i < poplen; i++) {
1707 actual[i] = pop();
1708 }
1709 // Field _state is uninitialized when calling push.
1710 for (int i = poplen; i < 5; i++) {
1711 actual[i] = CellTypeState::uninit;
1712 }
1713
1714 // put them back
1715 char push_ch = *out++;
1716 while (push_ch != '\0') {
1717 int idx = push_ch - '1';
1718 assert(idx >= 0 && idx < poplen, "wrong arguments");
1719 push(actual[idx]);
1720 push_ch = *out++;
1721 }
1722 }
1723
1724 void GenerateOopMap::ppop1(CellTypeState out) {
1725 CellTypeState actual = pop();
1726 check_type(out, actual);
1727 }
1728
1729 void GenerateOopMap::ppop(CellTypeState *out) {
1730 while (!(*out).is_bottom()) {
1731 ppop1(*out++);
1732 }
1733 }
1734
1735 void GenerateOopMap::ppush1(CellTypeState in) {
1736 assert(in.is_reference() || in.is_value(), "sanity check");
1737 push(in);
1738 }
1739
1740 void GenerateOopMap::ppush(CellTypeState *in) {
1741 while (!(*in).is_bottom()) {
1742 ppush1(*in++);
1743 }
1744 }
1745
1746 void GenerateOopMap::pp(CellTypeState *in, CellTypeState *out) {
1747 ppop(in);
1748 ppush(out);
1749 }
1750
1751 void GenerateOopMap::pp_new_ref(CellTypeState *in, int bci) {
1752 ppop(in);
1753 ppush1(CellTypeState::make_line_ref(bci));
1754 }
1755
1756 void GenerateOopMap::ppop_any(int poplen) {
1757 if (_stack_top >= poplen) {
1758 _stack_top -= poplen;
1759 } else {
1760 verify_error("stack underflow");
1761 }
1762 }
1763
1764 // Replace all occurrences of the state 'match' with the state 'replace'
1765 // in our current state vector.
1766 void GenerateOopMap::replace_all_CTS_matches(CellTypeState match,
1767 CellTypeState replace) {
1768 int i;
1769 int len = _max_locals + _stack_top;
1770 bool change = false;
1771
1772 for (i = len - 1; i >= 0; i--) {
1773 if (match.equal(_state[i])) {
1774 _state[i] = replace;
1775 }
1776 }
1777
1778 if (_monitor_top > 0) {
1779 int base = _max_locals + _max_stack;
1780 len = base + _monitor_top;
1781 for (i = len - 1; i >= base; i--) {
1782 if (match.equal(_state[i])) {
1783 _state[i] = replace;
1784 }
1785 }
1786 }
1787 }
1788
1789 void GenerateOopMap::do_checkcast() {
1790 CellTypeState actual = pop();
1791 check_type(refCTS, actual);
1792 push(actual);
1793 }
1794
1795 void GenerateOopMap::do_monitorenter(int bci) {
1796 CellTypeState actual = pop();
1797 if (_monitor_top == bad_monitors) {
1798 return;
1799 }
1800
1801 // Bail out when we get repeated locks on an identical monitor. This case
1802 // isn't too hard to handle and can be made to work if supporting nested
1803 // redundant synchronized statements becomes a priority.
1804 //
1805 // See also "Note" in do_monitorexit(), below.
1806 if (actual.is_lock_reference()) {
1807 _monitor_top = bad_monitors;
1808 _monitor_safe = false;
1809
1810 if (log_is_enabled(Info, monitormismatch)) {
1811 report_monitor_mismatch("nested redundant lock -- bailout...");
1812 }
1813 return;
1814 }
1815
1816 CellTypeState lock = CellTypeState::make_lock_ref(bci);
1817 check_type(refCTS, actual);
1818 if (!actual.is_info_top()) {
1819 replace_all_CTS_matches(actual, lock);
1820 monitor_push(lock);
1821 }
1822 }
1823
1824 void GenerateOopMap::do_monitorexit(int bci) {
1825 CellTypeState actual = pop();
1826 if (_monitor_top == bad_monitors) {
1827 return;
1828 }
1829 check_type(refCTS, actual);
1830 CellTypeState expected = monitor_pop();
1831 if (!actual.is_lock_reference() || !expected.equal(actual)) {
1832 // The monitor we are exiting is not verifiably the one
1833 // on the top of our monitor stack. This causes a monitor
1834 // mismatch.
1835 _monitor_top = bad_monitors;
1836 _monitor_safe = false;
1837
1838 // We need to mark this basic block as changed so that
1839 // this monitorexit will be visited again. We need to
1840 // do this to ensure that we have accounted for the
1841 // possibility that this bytecode will throw an
1842 // exception.
1843 BasicBlock* bb = get_basic_block_containing(bci);
1844 guarantee(bb != nullptr, "no basic block for bci");
1845 bb->set_changed(true);
1846 bb->_monitor_top = bad_monitors;
1847
1848 if (log_is_enabled(Info, monitormismatch)) {
1849 report_monitor_mismatch("improper monitor pair");
1850 }
1851 } else {
1852 // This code is a fix for the case where we have repeated
1853 // locking of the same object in straightline code. We clear
1854 // out the lock when it is popped from the monitor stack
1855 // and replace it with an unobtrusive reference value that can
1856 // be locked again.
1857 //
1858 // Note: when generateOopMap is fixed to properly handle repeated,
1859 // nested, redundant locks on the same object, then this
1860 // fix will need to be removed at that time.
1861 replace_all_CTS_matches(actual, CellTypeState::make_line_ref(bci));
1862 }
1863 }
1864
1865 void GenerateOopMap::do_return_monitor_check() {
1866 if (_monitor_top > 0) {
1867 // The monitor stack must be empty when we leave the method
1868 // for the monitors to be properly matched.
1869 _monitor_safe = false;
1870
1871 // Since there are no successors to the *return bytecode, it
1872 // isn't necessary to set _monitor_top to bad_monitors.
1873
1874 if (log_is_enabled(Info, monitormismatch)) {
1875 report_monitor_mismatch("non-empty monitor stack at return");
1876 }
1877 }
1878 }
1879
1880 void GenerateOopMap::do_jsr(int targ_bci) {
1881 push(CellTypeState::make_addr(targ_bci));
1882 }
1883
1884
1885
1886 void GenerateOopMap::do_ldc(int bci) {
1887 Bytecode_loadconstant ldc(methodHandle(Thread::current(), method()), bci);
1888 ConstantPool* cp = method()->constants();
1889 constantTag tag = cp->tag_at(ldc.pool_index()); // idx is index in resolved_references
1890 BasicType bt = ldc.result_type();
1891 #ifdef ASSERT
1892 BasicType tag_bt = (tag.is_dynamic_constant() || tag.is_dynamic_constant_in_error()) ? bt : tag.basic_type();
1893 assert(bt == tag_bt, "same result");
1894 #endif
1895 CellTypeState cts;
1896 if (is_reference_type(bt)) { // could be T_ARRAY with condy
1897 assert(!tag.is_string_index() && !tag.is_klass_index(), "Unexpected index tag");
1898 cts = CellTypeState::make_line_ref(bci);
1899 } else {
1900 cts = valCTS;
1901 }
1902 ppush1(cts);
1903 }
1904
1905 void GenerateOopMap::do_multianewarray(int dims, int bci) {
1906 assert(dims >= 1, "sanity check");
1907 for(int i = dims -1; i >=0; i--) {
1908 ppop1(valCTS);
1909 }
1910 ppush1(CellTypeState::make_line_ref(bci));
1911 }
1912
1913 void GenerateOopMap::do_astore(int idx) {
1914 CellTypeState r_or_p = pop();
1915 if (!r_or_p.is_address() && !r_or_p.is_reference()) {
1916 // We actually expected ref or pc, but we only report that we expected a ref. It does not
1917 // really matter (at least for now)
1918 verify_error("wrong type on stack (found: %c, expected: {pr})", r_or_p.to_char());
1919 return;
1920 }
1921 set_var(idx, r_or_p);
1922 }
1923
1924 // Copies bottom/zero terminated CTS string from "src" into "dst".
1925 // Does NOT terminate with a bottom. Returns the number of cells copied.
1926 int GenerateOopMap::copy_cts(CellTypeState *dst, CellTypeState *src) {
1927 int idx = 0;
1928 while (!src[idx].is_bottom()) {
1929 dst[idx] = src[idx];
1930 idx++;
1931 }
1932 return idx;
1933 }
1934
1935 void GenerateOopMap::do_field(int is_get, int is_static, int idx, int bci, Bytecodes::Code bc) {
1936 // Dig up signature for field in constant pool
1937 ConstantPool* cp = method()->constants();
1938 int nameAndTypeIdx = cp->name_and_type_ref_index_at(idx, bc);
1939 int signatureIdx = cp->signature_ref_index_at(nameAndTypeIdx);
1940 Symbol* signature = cp->symbol_at(signatureIdx);
1941
1942 CellTypeState temp[4];
1943 CellTypeState *eff = signature_to_effect(signature, bci, temp);
1944
1945 CellTypeState in[4];
1946 CellTypeState *out;
1947 int i = 0;
1948
1949 if (is_get) {
1950 out = eff;
1951 } else {
1952 out = epsilonCTS;
1953 i = copy_cts(in, eff);
1954 }
1955 if (!is_static) {
1956 in[i++] = CellTypeState::ref;
1957 }
1958 in[i] = CellTypeState::bottom;
1959 assert(i<=3, "sanity check");
1960 pp(in, out);
1961 }
1962
1963 void GenerateOopMap::do_method(int is_static, int idx, int bci, Bytecodes::Code bc) {
1964 // Dig up signature for field in constant pool
1965 ConstantPool* cp = _method->constants();
1966 Symbol* signature = cp->signature_ref_at(idx, bc);
1967
1968 // Parse method signature
1969 CellTypeState out[4];
1970 CellTypeState in[MAXARGSIZE+1]; // Includes result
1971 ComputeCallStack cse(signature);
1972
1973 // Compute return type
1974 int res_length= cse.compute_for_returntype(out);
1975
1976 // Temporary hack.
1977 if (out[0].equal(CellTypeState::ref) && out[1].equal(CellTypeState::bottom)) {
1978 out[0] = CellTypeState::make_line_ref(bci);
1979 }
1980
1981 assert(res_length<=4, "max value should be vv");
1982
1983 // Compute arguments
1984 int arg_length = cse.compute_for_parameters(is_static != 0, in);
1985 assert(arg_length<=MAXARGSIZE, "too many locals");
1986
1987 // Pop arguments
1988 for (int i = arg_length - 1; i >= 0; i--) ppop1(in[i]);// Do args in reverse order.
1989
1990 // Report results
1991 if (_report_result_for_send == true) {
1992 fill_stackmap_for_opcodes(_itr_send, vars(), stack(), _stack_top);
1993 _report_result_for_send = false;
1994 }
1995
1996 // Push return address
1997 ppush(out);
1998 }
1999
2000 // This is used to parse the signature for fields, since they are very simple...
2001 CellTypeState *GenerateOopMap::signature_to_effect(const Symbol* sig, int bci, CellTypeState *out) {
2002 // Object and array
2003 BasicType bt = Signature::basic_type(sig);
2004 if (is_reference_type(bt)) {
2005 out[0] = CellTypeState::make_line_ref(bci);
2006 out[1] = CellTypeState::bottom;
2007 return out;
2008 }
2009 if (is_double_word_type(bt)) return vvCTS; // Long and Double
2010 if (bt == T_VOID) return epsilonCTS; // Void
2011 return vCTS; // Otherwise
2012 }
2013
2014 uint64_t GenerateOopMap::_total_byte_count = 0;
2015 elapsedTimer GenerateOopMap::_total_oopmap_time;
2016
2017 // This function assumes "bcs" is at a "ret" instruction and that the vars
2018 // state is valid for that instruction. Furthermore, the ret instruction
2019 // must be the last instruction in "bb" (we store information about the
2020 // "ret" in "bb").
2021 void GenerateOopMap::ret_jump_targets_do(BytecodeStream *bcs, jmpFct_t jmpFct, int varNo, int *data) {
2022 CellTypeState ra = vars()[varNo];
2023 if (!ra.is_good_address()) {
2024 verify_error("ret returns from two jsr subroutines?");
2025 return;
2026 }
2027 int target = ra.get_info();
2028
2029 RetTableEntry* rtEnt = _rt.find_jsrs_for_target(target);
2030 int bci = bcs->bci();
2031 for (int i = 0; i < rtEnt->nof_jsrs(); i++) {
2032 int target_bci = rtEnt->jsrs(i);
2033 // Make sure a jrtRet does not set the changed bit for dead basicblock.
2034 BasicBlock* jsr_bb = get_basic_block_containing(target_bci - 1);
2035 debug_only(BasicBlock* target_bb = &jsr_bb[1];)
2036 assert(target_bb == get_basic_block_at(target_bci), "wrong calc. of successor basicblock");
2037 bool alive = jsr_bb->is_alive();
2038 if (TraceNewOopMapGeneration) {
2039 tty->print("pc = %d, ret -> %d alive: %s\n", bci, target_bci, alive ? "true" : "false");
2040 }
2041 if (alive) jmpFct(this, target_bci, data);
2042 }
2043 }
2044
2045 //
2046 // Debug method
2047 //
2048 char* GenerateOopMap::state_vec_to_string(CellTypeState* vec, int len) {
2049 #ifdef ASSERT
2050 int checklen = MAX3(_max_locals, _max_stack, _max_monitors) + 1;
2051 assert(len < checklen, "state_vec_buf overflow");
2052 #endif
2053 for (int i = 0; i < len; i++) _state_vec_buf[i] = vec[i].to_char();
2054 _state_vec_buf[len] = 0;
2055 return _state_vec_buf;
2056 }
2057
2058 void GenerateOopMap::print_time() {
2059 tty->print_cr ("Accumulated oopmap times:");
2060 tty->print_cr ("---------------------------");
2061 tty->print_cr (" Total : %3.3f sec.", GenerateOopMap::_total_oopmap_time.seconds());
2062 tty->print_cr (" (%3.0f bytecodes per sec) ",
2063 (double)GenerateOopMap::_total_byte_count / GenerateOopMap::_total_oopmap_time.seconds());
2064 }
2065
2066 //
2067 // ============ Main Entry Point ===========
2068 //
2069 GenerateOopMap::GenerateOopMap(const methodHandle& method) {
2070 // We have to initialize all variables here, that can be queried directly
2071 _method = method;
2072 _max_locals=0;
2073 _init_vars = nullptr;
2074
2075 #ifndef PRODUCT
2076 // If we are doing a detailed trace, include the regular trace information.
2077 if (TraceNewOopMapGenerationDetailed) {
2078 TraceNewOopMapGeneration = true;
2079 }
2080 #endif
2081 }
2082
2083 bool GenerateOopMap::compute_map(Thread* current) {
2084 #ifndef PRODUCT
2085 if (TimeOopMap2) {
2086 method()->print_short_name(tty);
2087 tty->print(" ");
2088 }
2089 if (TimeOopMap) {
2090 _total_byte_count += method()->code_size();
2091 }
2092 #endif
2093 TraceTime t_single("oopmap time", TimeOopMap2);
2094 TraceTime t_all(nullptr, &_total_oopmap_time, TimeOopMap);
2095
2096 // Initialize values
2097 _got_error = false;
2098 _conflict = false;
2099 _max_locals = method()->max_locals();
2100 _max_stack = method()->max_stack();
2101 _has_exceptions = (method()->has_exception_handler());
2102 _nof_refval_conflicts = 0;
2103 _init_vars = new GrowableArray<intptr_t>(5); // There are seldom more than 5 init_vars
2104 _report_result = false;
2105 _report_result_for_send = false;
2106 _new_var_map = nullptr;
2107 _ret_adr_tos = new GrowableArray<int>(5); // 5 seems like a good number;
2108 _did_rewriting = false;
2109 _did_relocation = false;
2110
2111 if (TraceNewOopMapGeneration) {
2112 tty->print("Method name: %s\n", method()->name()->as_C_string());
2113 if (Verbose) {
2114 _method->print_codes();
2115 tty->print_cr("Exception table:");
2116 ExceptionTable excps(method());
2117 for(int i = 0; i < excps.length(); i ++) {
2118 tty->print_cr("[%d - %d] -> %d",
2119 excps.start_pc(i), excps.end_pc(i), excps.handler_pc(i));
2120 }
2121 }
2122 }
2123
2124 // if no code - do nothing
2125 // compiler needs info
2126 if (method()->code_size() == 0 || _max_locals + method()->max_stack() == 0) {
2127 fill_stackmap_prolog(0);
2128 fill_stackmap_epilog();
2129 return true;
2130 }
2131 // Step 1: Compute all jump targets and their return value
2132 if (!_got_error)
2133 _rt.compute_ret_table(_method);
2134
2135 // Step 2: Find all basic blocks and count GC points
2136 if (!_got_error)
2137 mark_bbheaders_and_count_gc_points();
2138
2139 // Step 3: Calculate stack maps
2140 if (!_got_error)
2141 do_interpretation();
2142
2143 // Step 4:Return results
2144 if (!_got_error && report_results())
2145 report_result();
2146
2147 return !_got_error;
2148 }
2149
2150 // Error handling methods
2151 //
2152 // If we compute from a suitable JavaThread then we create an exception for the GenerateOopMap
2153 // calling code to retrieve (via exception()) and throw if desired (in most cases errors are ignored).
2154 // Otherwise it is considered a fatal error to hit malformed bytecode.
2155 void GenerateOopMap::error_work(const char *format, va_list ap) {
2156 _got_error = true;
2157 char msg_buffer[512];
2158 os::vsnprintf(msg_buffer, sizeof(msg_buffer), format, ap);
2159 // Append method name
2160 char msg_buffer2[512];
2161 os::snprintf(msg_buffer2, sizeof(msg_buffer2), "%s in method %s", msg_buffer, method()->name()->as_C_string());
2162 Thread* current = Thread::current();
2163 if (current->can_call_java()) {
2164 _exception = Exceptions::new_exception(JavaThread::cast(current),
2165 vmSymbols::java_lang_LinkageError(),
2166 msg_buffer2);
2167 } else {
2168 fatal("%s", msg_buffer2);
2169 }
2170 }
2171
2172 void GenerateOopMap::report_error(const char *format, ...) {
2173 va_list ap;
2174 va_start(ap, format);
2175 error_work(format, ap);
2176 }
2177
2178 void GenerateOopMap::verify_error(const char *format, ...) {
2179 // We do not distinguish between different types of errors for verification
2180 // errors. Let the verifier give a better message.
2181 report_error("Illegal class file encountered. Try running with -Xverify:all");
2182 }
2183
2184 //
2185 // Report result opcodes
2186 //
2187 void GenerateOopMap::report_result() {
2188
2189 if (TraceNewOopMapGeneration) tty->print_cr("Report result pass");
2190
2191 // We now want to report the result of the parse
2192 _report_result = true;
2193
2194 // Prolog code
2195 fill_stackmap_prolog(_gc_points);
2196
2197 // Mark everything changed, then do one interpretation pass.
2198 for (int i = 0; i<_bb_count; i++) {
2199 if (_basic_blocks[i].is_reachable()) {
2200 _basic_blocks[i].set_changed(true);
2201 interp_bb(&_basic_blocks[i]);
2202 }
2203 }
2204
2205 // Note: Since we are skipping dead-code when we are reporting results, then
2206 // the no. of encountered gc-points might be fewer than the previously number
2207 // we have counted. (dead-code is a pain - it should be removed before we get here)
2208 fill_stackmap_epilog();
2209
2210 // Report initvars
2211 fill_init_vars(_init_vars);
2212
2213 _report_result = false;
2214 }
2215
2216 void GenerateOopMap::result_for_basicblock(int bci) {
2217 if (TraceNewOopMapGeneration) tty->print_cr("Report result pass for basicblock");
2218
2219 // We now want to report the result of the parse
2220 _report_result = true;
2221
2222 // Find basicblock and report results
2223 BasicBlock* bb = get_basic_block_containing(bci);
2224 guarantee(bb != nullptr, "no basic block for bci");
2225 assert(bb->is_reachable(), "getting result from unreachable basicblock");
2226 bb->set_changed(true);
2227 interp_bb(bb);
2228 }
2229
2230 //
2231 // Conflict handling code
2232 //
2233
2234 void GenerateOopMap::record_refval_conflict(int varNo) {
2235 assert(varNo>=0 && varNo< _max_locals, "index out of range");
2236
2237 if (TraceOopMapRewrites) {
2238 tty->print("### Conflict detected (local no: %d)\n", varNo);
2239 }
2240
2241 if (!_new_var_map) {
2242 _new_var_map = NEW_RESOURCE_ARRAY(int, _max_locals);
2243 for (int k = 0; k < _max_locals; k++) _new_var_map[k] = k;
2244 }
2245
2246 if ( _new_var_map[varNo] == varNo) {
2247 // Check if max. number of locals has been reached
2248 if (_max_locals + _nof_refval_conflicts >= MAX_LOCAL_VARS) {
2249 report_error("Rewriting exceeded local variable limit");
2250 return;
2251 }
2252 _new_var_map[varNo] = _max_locals + _nof_refval_conflicts;
2253 _nof_refval_conflicts++;
2254 }
2255 }
2256
2257 void GenerateOopMap::rewrite_refval_conflicts()
2258 {
2259 // We can get here two ways: Either a rewrite conflict was detected, or
2260 // an uninitialize reference was detected. In the second case, we do not
2261 // do any rewriting, we just want to recompute the reference set with the
2262 // new information
2263
2264 int nof_conflicts = 0; // Used for debugging only
2265
2266 if ( _nof_refval_conflicts == 0 )
2267 return;
2268
2269 // Check if rewrites are allowed in this parse.
2270 if (!allow_rewrites()) {
2271 fatal("Rewriting method not allowed at this stage");
2272 }
2273
2274
2275 // Tracing flag
2276 _did_rewriting = true;
2277
2278 if (TraceOopMapRewrites) {
2279 tty->print_cr("ref/value conflict for method %s - bytecodes are getting rewritten", method()->name()->as_C_string());
2280 method()->print();
2281 method()->print_codes();
2282 }
2283
2284 assert(_new_var_map!=nullptr, "nothing to rewrite");
2285 assert(_conflict==true, "We should not be here");
2286
2287 compute_ret_adr_at_TOS();
2288 if (!_got_error) {
2289 for (int k = 0; k < _max_locals && !_got_error; k++) {
2290 if (_new_var_map[k] != k) {
2291 if (TraceOopMapRewrites) {
2292 tty->print_cr("Rewriting: %d -> %d", k, _new_var_map[k]);
2293 }
2294 rewrite_refval_conflict(k, _new_var_map[k]);
2295 if (_got_error) return;
2296 nof_conflicts++;
2297 }
2298 }
2299 }
2300
2301 assert(nof_conflicts == _nof_refval_conflicts, "sanity check");
2302
2303 // Adjust the number of locals
2304 method()->set_max_locals(_max_locals+_nof_refval_conflicts);
2305 _max_locals += _nof_refval_conflicts;
2306
2307 // That was that...
2308 _new_var_map = nullptr;
2309 _nof_refval_conflicts = 0;
2310 }
2311
2312 void GenerateOopMap::rewrite_refval_conflict(int from, int to) {
2313 bool startOver;
2314 do {
2315 // Make sure that the BytecodeStream is constructed in the loop, since
2316 // during rewriting a new method is going to be used, and the next time
2317 // around we want to use that.
2318 BytecodeStream bcs(_method);
2319 startOver = false;
2320
2321 while( !startOver && !_got_error &&
2322 // test bcs in case method changed and it became invalid
2323 bcs.next() >=0) {
2324 startOver = rewrite_refval_conflict_inst(&bcs, from, to);
2325 }
2326 } while (startOver && !_got_error);
2327 }
2328
2329 /* If the current instruction is one that uses local variable "from"
2330 in a ref way, change it to use "to". There's a subtle reason why we
2331 renumber the ref uses and not the non-ref uses: non-ref uses may be
2332 2 slots wide (double, long) which would necessitate keeping track of
2333 whether we should add one or two variables to the method. If the change
2334 affected the width of some instruction, returns "TRUE"; otherwise, returns "FALSE".
2335 Another reason for moving ref's value is for solving (addr, ref) conflicts, which
2336 both uses aload/astore methods.
2337 */
2338 bool GenerateOopMap::rewrite_refval_conflict_inst(BytecodeStream *itr, int from, int to) {
2339 Bytecodes::Code bc = itr->code();
2340 int index;
2341 int bci = itr->bci();
2342
2343 if (is_aload(itr, &index) && index == from) {
2344 if (TraceOopMapRewrites) {
2345 tty->print_cr("Rewriting aload at bci: %d", bci);
2346 }
2347 return rewrite_load_or_store(itr, Bytecodes::_aload, Bytecodes::_aload_0, to);
2348 }
2349
2350 if (is_astore(itr, &index) && index == from) {
2351 if (!stack_top_holds_ret_addr(bci)) {
2352 if (TraceOopMapRewrites) {
2353 tty->print_cr("Rewriting astore at bci: %d", bci);
2354 }
2355 return rewrite_load_or_store(itr, Bytecodes::_astore, Bytecodes::_astore_0, to);
2356 } else {
2357 if (TraceOopMapRewrites) {
2358 tty->print_cr("Suppress rewriting of astore at bci: %d", bci);
2359 }
2360 }
2361 }
2362
2363 return false;
2364 }
2365
2366 // The argument to this method is:
2367 // bc : Current bytecode
2368 // bcN : either _aload or _astore
2369 // bc0 : either _aload_0 or _astore_0
2370 bool GenerateOopMap::rewrite_load_or_store(BytecodeStream *bcs, Bytecodes::Code bcN, Bytecodes::Code bc0, unsigned int varNo) {
2371 assert(bcN == Bytecodes::_astore || bcN == Bytecodes::_aload, "wrong argument (bcN)");
2372 assert(bc0 == Bytecodes::_astore_0 || bc0 == Bytecodes::_aload_0, "wrong argument (bc0)");
2373 int ilen = Bytecodes::length_at(_method(), bcs->bcp());
2374 int newIlen;
2375
2376 if (ilen == 4) {
2377 // Original instruction was wide; keep it wide for simplicity
2378 newIlen = 4;
2379 } else if (varNo < 4)
2380 newIlen = 1;
2381 else if (varNo >= 256)
2382 newIlen = 4;
2383 else
2384 newIlen = 2;
2385
2386 // If we need to relocate in order to patch the byte, we
2387 // do the patching in a temp. buffer, that is passed to the reloc.
2388 // The patching of the bytecode stream is then done by the Relocator.
2389 // This is necessary, since relocating the instruction at a certain bci, might
2390 // also relocate that instruction, e.g., if a _goto before it gets widen to a _goto_w.
2391 // Hence, we do not know which bci to patch after relocation.
2392
2393 assert(newIlen <= 4, "sanity check");
2394 u_char inst_buffer[4]; // Max. instruction size is 4.
2395 address bcp;
2396
2397 if (newIlen != ilen) {
2398 // Relocation needed do patching in temp. buffer
2399 bcp = (address)inst_buffer;
2400 } else {
2401 bcp = _method->bcp_from(bcs->bci());
2402 }
2403
2404 // Patch either directly in Method* or in temp. buffer
2405 if (newIlen == 1) {
2406 assert(varNo < 4, "varNo too large");
2407 *bcp = (u1)(bc0 + varNo);
2408 } else if (newIlen == 2) {
2409 assert(varNo < 256, "2-byte index needed!");
2410 *(bcp + 0) = bcN;
2411 *(bcp + 1) = (u1)varNo;
2412 } else {
2413 assert(newIlen == 4, "Wrong instruction length");
2414 *(bcp + 0) = Bytecodes::_wide;
2415 *(bcp + 1) = bcN;
2416 Bytes::put_Java_u2(bcp+2, (u2)varNo);
2417 }
2418
2419 if (newIlen != ilen) {
2420 expand_current_instr(bcs->bci(), ilen, newIlen, inst_buffer);
2421 }
2422
2423
2424 return (newIlen != ilen);
2425 }
2426
2427 class RelocCallback : public RelocatorListener {
2428 private:
2429 GenerateOopMap* _gom;
2430 public:
2431 RelocCallback(GenerateOopMap* gom) { _gom = gom; };
2432
2433 // Callback method
2434 virtual void relocated(int bci, int delta, int new_code_length) {
2435 _gom->update_basic_blocks (bci, delta, new_code_length);
2436 _gom->update_ret_adr_at_TOS(bci, delta);
2437 _gom->_rt.update_ret_table (bci, delta);
2438 }
2439 };
2440
2441 // Returns true if expanding was successful. Otherwise, reports an error and
2442 // returns false.
2443 void GenerateOopMap::expand_current_instr(int bci, int ilen, int newIlen, u_char inst_buffer[]) {
2444 JavaThread* THREAD = JavaThread::current(); // For exception macros.
2445 RelocCallback rcb(this);
2446 Relocator rc(_method, &rcb);
2447 methodHandle m= rc.insert_space_at(bci, newIlen, inst_buffer, THREAD);
2448 if (m.is_null() || HAS_PENDING_EXCEPTION) {
2449 report_error("could not rewrite method - exception occurred or bytecode buffer overflow");
2450 return;
2451 }
2452
2453 // Relocator returns a new method.
2454 _did_relocation = true;
2455 _method = m;
2456 }
2457
2458
2459 bool GenerateOopMap::is_astore(BytecodeStream *itr, int *index) {
2460 Bytecodes::Code bc = itr->code();
2461 switch(bc) {
2462 case Bytecodes::_astore_0:
2463 case Bytecodes::_astore_1:
2464 case Bytecodes::_astore_2:
2465 case Bytecodes::_astore_3:
2466 *index = bc - Bytecodes::_astore_0;
2467 return true;
2468 case Bytecodes::_astore:
2469 *index = itr->get_index();
2470 return true;
2471 default:
2472 return false;
2473 }
2474 }
2475
2476 bool GenerateOopMap::is_aload(BytecodeStream *itr, int *index) {
2477 Bytecodes::Code bc = itr->code();
2478 switch(bc) {
2479 case Bytecodes::_aload_0:
2480 case Bytecodes::_aload_1:
2481 case Bytecodes::_aload_2:
2482 case Bytecodes::_aload_3:
2483 *index = bc - Bytecodes::_aload_0;
2484 return true;
2485
2486 case Bytecodes::_aload:
2487 *index = itr->get_index();
2488 return true;
2489
2490 default:
2491 return false;
2492 }
2493 }
2494
2495
2496 // Return true iff the top of the operand stack holds a return address at
2497 // the current instruction
2498 bool GenerateOopMap::stack_top_holds_ret_addr(int bci) {
2499 for(int i = 0; i < _ret_adr_tos->length(); i++) {
2500 if (_ret_adr_tos->at(i) == bci)
2501 return true;
2502 }
2503
2504 return false;
2505 }
2506
2507 void GenerateOopMap::compute_ret_adr_at_TOS() {
2508 assert(_ret_adr_tos != nullptr, "must be initialized");
2509 _ret_adr_tos->clear();
2510
2511 for (int i = 0; i < bb_count(); i++) {
2512 BasicBlock* bb = &_basic_blocks[i];
2513
2514 // Make sure to only check basicblocks that are reachable
2515 if (bb->is_reachable()) {
2516
2517 // For each Basic block we check all instructions
2518 BytecodeStream bcs(_method);
2519 bcs.set_interval(bb->_bci, next_bb_start_pc(bb));
2520
2521 restore_state(bb);
2522
2523 while (bcs.next()>=0 && !_got_error) {
2524 // TDT: should this be is_good_address() ?
2525 if (_stack_top > 0 && stack()[_stack_top-1].is_address()) {
2526 _ret_adr_tos->append(bcs.bci());
2527 if (TraceNewOopMapGeneration) {
2528 tty->print_cr("Ret_adr TOS at bci: %d", bcs.bci());
2529 }
2530 }
2531 interp1(&bcs);
2532 }
2533 }
2534 }
2535 }
2536
2537 void GenerateOopMap::update_ret_adr_at_TOS(int bci, int delta) {
2538 for(int i = 0; i < _ret_adr_tos->length(); i++) {
2539 int v = _ret_adr_tos->at(i);
2540 if (v > bci) _ret_adr_tos->at_put(i, v + delta);
2541 }
2542 }
2543
2544 // ===================================================================
2545
2546 #ifndef PRODUCT
2547 int ResolveOopMapConflicts::_nof_invocations = 0;
2548 int ResolveOopMapConflicts::_nof_rewrites = 0;
2549 int ResolveOopMapConflicts::_nof_relocations = 0;
2550 #endif
2551
2552 methodHandle ResolveOopMapConflicts::do_potential_rewrite(TRAPS) {
2553 if (!compute_map(THREAD)) {
2554 THROW_HANDLE_(exception(), methodHandle());
2555 }
2556
2557 #ifndef PRODUCT
2558 // Tracking and statistics
2559 if (PrintRewrites) {
2560 _nof_invocations++;
2561 if (did_rewriting()) {
2562 _nof_rewrites++;
2563 if (did_relocation()) _nof_relocations++;
2564 tty->print("Method was rewritten %s: ", (did_relocation()) ? "and relocated" : "");
2565 method()->print_value(); tty->cr();
2566 tty->print_cr("Cand.: %d rewrts: %d (%d%%) reloc.: %d (%d%%)",
2567 _nof_invocations,
2568 _nof_rewrites, (_nof_rewrites * 100) / _nof_invocations,
2569 _nof_relocations, (_nof_relocations * 100) / _nof_invocations);
2570 }
2571 }
2572 #endif
2573 return methodHandle(THREAD, method());
2574 }