1 /*
2 * Copyright (c) 1997, 2023, 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/vmSymbols.hpp"
27 #include "interpreter/bytecodeStream.hpp"
28 #include "logging/log.hpp"
29 #include "logging/logStream.hpp"
30 #include "memory/allocation.inline.hpp"
31 #include "memory/resourceArea.hpp"
32 #include "oops/constantPool.hpp"
33 #include "oops/generateOopMap.hpp"
34 #include "oops/oop.inline.hpp"
35 #include "oops/symbol.hpp"
36 #include "runtime/handles.inline.hpp"
37 #include "runtime/java.hpp"
38 #include "runtime/os.hpp"
39 #include "runtime/relocator.hpp"
40 #include "runtime/timerTrace.hpp"
41 #include "utilities/bitMap.inline.hpp"
42 #include "utilities/ostream.hpp"
43
44 //
45 //
46 // Compute stack layouts for each instruction in method.
47 //
48 // Problems:
49 // - What to do about jsr with different types of local vars?
50 // Need maps that are conditional on jsr path?
51 // - Jsr and exceptions should be done more efficiently (the retAddr stuff)
52 //
53 // Alternative:
54 // - Could extend verifier to provide this information.
55 // For: one fewer abstract interpreter to maintain. Against: the verifier
56 // solves a bigger problem so slower (undesirable to force verification of
57 // everything?).
58 //
59 // Algorithm:
60 // Partition bytecodes into basic blocks
61 // For each basic block: store entry state (vars, stack). For instructions
62 // inside basic blocks we do not store any state (instead we recompute it
63 // from state produced by previous instruction).
64 //
65 // Perform abstract interpretation of bytecodes over this lattice:
66 //
67 // _--'#'--_
68 // / / \ \
69 // / / \ \
70 // / | | \
71 // 'r' 'v' 'p' ' '
72 // \ | | /
73 // \ \ / /
74 // \ \ / /
75 // -- '@' --
76 //
77 // '#' top, result of conflict merge
78 // 'r' reference type
79 // 'v' value type
80 // 'p' pc type for jsr/ret
81 // ' ' uninitialized; never occurs on operand stack in Java
82 // '@' bottom/unexecuted; initial state each bytecode.
83 //
84 // Basic block headers are the only merge points. We use this iteration to
85 // compute the information:
86 //
87 // find basic blocks;
88 // initialize them with uninitialized state;
89 // initialize first BB according to method signature;
90 // mark first BB changed
91 // while (some BB is changed) do {
92 // perform abstract interpration of all bytecodes in BB;
93 // merge exit state of BB into entry state of all successor BBs,
94 // noting if any of these change;
95 // }
96 //
97 // One additional complication is necessary. The jsr instruction pushes
98 // a return PC on the stack (a 'p' type in the abstract interpretation).
99 // To be able to process "ret" bytecodes, we keep track of these return
100 // PC's in a 'retAddrs' structure in abstract interpreter context (when
101 // processing a "ret" bytecodes, it is not sufficient to know that it gets
102 // an argument of the right type 'p'; we need to know which address it
103 // returns to).
104 //
105 // (Note this comment is borrowed form the original author of the algorithm)
106
107 // ComputeCallStack
108 //
109 // Specialization of SignatureIterator - compute the effects of a call
110 //
111 class ComputeCallStack : public SignatureIterator {
112 CellTypeState *_effect;
113 int _idx;
114
115 void setup();
116 void set(CellTypeState state) { _effect[_idx++] = state; }
117 int length() { return _idx; };
118
119 friend class SignatureIterator; // so do_parameters_on can call do_type
120 void do_type(BasicType type, bool for_return = false) {
121 if (for_return && type == T_VOID) {
122 set(CellTypeState::bottom);
123 } else if (is_reference_type(type)) {
124 set(CellTypeState::ref);
125 } else {
126 assert(is_java_primitive(type), "");
127 set(CellTypeState::value);
128 if (is_double_word_type(type)) {
129 set(CellTypeState::value);
130 }
131 }
132 }
133
134 public:
135 ComputeCallStack(Symbol* signature) : SignatureIterator(signature) {};
136
137 // Compute methods
138 int compute_for_parameters(bool is_static, CellTypeState *effect) {
139 _idx = 0;
140 _effect = effect;
141
142 if (!is_static)
143 effect[_idx++] = CellTypeState::ref;
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 assert(!fellThrough, "should not happen");
440 bb_mark_fct(this, bci + Bytecodes::length_for(bytecode), nullptr);
441 break;
442 case Bytecodes::_jsr_w:
443 assert(!fellThrough, "should not happen");
444 bb_mark_fct(this, bci + Bytecodes::length_for(bytecode), nullptr);
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 reachable_basicblock(this, bci + Bytecodes::length_for(bytecode), &change);
506 break;
507 default:
508 break;
509 }
510 if (fell_through) {
511 // Mark successor as alive
512 if (bb[1].is_dead()) {
513 bb[1].mark_as_alive();
514 change = 1;
515 }
516 }
517 }
518 }
519 }
520 }
521
522 /* If the current instruction in "c" has no effect on control flow,
523 returns "true". Otherwise, calls "jmpFct" one or more times, with
524 "c", an appropriate "pcDelta", and "data" as arguments, then
525 returns "false". There is one exception: if the current
526 instruction is a "ret", returns "false" without calling "jmpFct".
527 Arrangements for tracking the control flow of a "ret" must be made
528 externally. */
529 bool GenerateOopMap::jump_targets_do(BytecodeStream *bcs, jmpFct_t jmpFct, int *data) {
530 int bci = bcs->bci();
531
532 switch (bcs->code()) {
533 case Bytecodes::_ifeq:
534 case Bytecodes::_ifne:
535 case Bytecodes::_iflt:
536 case Bytecodes::_ifge:
537 case Bytecodes::_ifgt:
538 case Bytecodes::_ifle:
539 case Bytecodes::_if_icmpeq:
540 case Bytecodes::_if_icmpne:
541 case Bytecodes::_if_icmplt:
542 case Bytecodes::_if_icmpge:
543 case Bytecodes::_if_icmpgt:
544 case Bytecodes::_if_icmple:
545 case Bytecodes::_if_acmpeq:
546 case Bytecodes::_if_acmpne:
547 case Bytecodes::_ifnull:
548 case Bytecodes::_ifnonnull:
549 (*jmpFct)(this, bcs->dest(), data);
550 // Class files verified by the old verifier can have a conditional branch
551 // as their last bytecode, provided the conditional branch is unreachable
552 // during execution. Check if this instruction is the method's last bytecode
553 // and, if so, don't call the jmpFct.
554 if (bci + 3 < method()->code_size()) {
555 (*jmpFct)(this, bci + 3, data);
556 }
557 break;
558
559 case Bytecodes::_goto:
560 (*jmpFct)(this, bcs->dest(), data);
561 break;
562 case Bytecodes::_goto_w:
563 (*jmpFct)(this, bcs->dest_w(), data);
564 break;
565 case Bytecodes::_tableswitch:
566 { Bytecode_tableswitch tableswitch(method(), bcs->bcp());
567 int len = tableswitch.length();
568
569 (*jmpFct)(this, bci + tableswitch.default_offset(), data); /* Default. jump address */
570 while (--len >= 0) {
571 (*jmpFct)(this, bci + tableswitch.dest_offset_at(len), data);
572 }
573 break;
574 }
575
576 case Bytecodes::_lookupswitch:
577 { Bytecode_lookupswitch lookupswitch(method(), bcs->bcp());
578 int npairs = lookupswitch.number_of_pairs();
579 (*jmpFct)(this, bci + lookupswitch.default_offset(), data); /* Default. */
580 while(--npairs >= 0) {
581 LookupswitchPair pair = lookupswitch.pair_at(npairs);
582 (*jmpFct)(this, bci + pair.offset(), data);
583 }
584 break;
585 }
586 case Bytecodes::_jsr:
587 assert(bcs->is_wide()==false, "sanity check");
588 (*jmpFct)(this, bcs->dest(), data);
589
590
591
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::_invokevirtual:
1606 case Bytecodes::_invokespecial: do_method(false, false, itr->get_index_u2(), itr->bci(), itr->code()); break;
1607 case Bytecodes::_invokestatic: do_method(true, false, itr->get_index_u2(), itr->bci(), itr->code()); break;
1608 case Bytecodes::_invokedynamic: do_method(true, false, itr->get_index_u4(), itr->bci(), itr->code()); break;
1609 case Bytecodes::_invokeinterface: do_method(false, true, itr->get_index_u2(), 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 case Bytecodes::_ifnull:
1630 case Bytecodes::_ifnonnull: ppop1(refCTS); break;
1631 case Bytecodes::_multianewarray: do_multianewarray(*(itr->bcp()+3), itr->bci()); break;
1632
1633 case Bytecodes::_wide: fatal("Iterator should skip this bytecode"); break;
1634 case Bytecodes::_ret: break;
1635
1636 // Java opcodes
1637 case Bytecodes::_lookupswitch: ppop1(valCTS); break;
1638
1639 default:
1640 tty->print("unexpected opcode: %d\n", itr->code());
1641 ShouldNotReachHere();
1642 break;
1643 }
1644 }
1645
1646 void GenerateOopMap::check_type(CellTypeState expected, CellTypeState actual) {
1647 if (!expected.equal_kind(actual)) {
1648 verify_error("wrong type on stack (found: %c expected: %c)", actual.to_char(), expected.to_char());
1649 }
1650 }
1651
1652 void GenerateOopMap::ppstore(CellTypeState *in, int loc_no) {
1653 while(!(*in).is_bottom()) {
1654 CellTypeState expected =*in++;
1655 CellTypeState actual = pop();
1656 check_type(expected, actual);
1657 assert(loc_no >= 0, "sanity check");
1658 set_var(loc_no++, actual);
1659 }
1660 }
1661
1662 void GenerateOopMap::ppload(CellTypeState *out, int loc_no) {
1663 while(!(*out).is_bottom()) {
1664 CellTypeState out1 = *out++;
1665 CellTypeState vcts = get_var(loc_no);
1666 assert(out1.can_be_reference() || out1.can_be_value(),
1667 "can only load refs. and values.");
1668 if (out1.is_reference()) {
1669 assert(loc_no>=0, "sanity check");
1670 if (!vcts.is_reference()) {
1671 // We were asked to push a reference, but the type of the
1672 // variable can be something else
1673 _conflict = true;
1674 if (vcts.can_be_uninit()) {
1675 // It is a ref-uninit conflict (at least). If there are other
1676 // problems, we'll get them in the next round
1677 add_to_ref_init_set(loc_no);
1678 vcts = out1;
1679 } else {
1680 // It wasn't a ref-uninit conflict. So must be a
1681 // ref-val or ref-pc conflict. Split the variable.
1682 record_refval_conflict(loc_no);
1683 vcts = out1;
1684 }
1685 push(out1); // recover...
1686 } else {
1687 push(vcts); // preserve reference.
1688 }
1689 // Otherwise it is a conflict, but one that verification would
1690 // have caught if illegal. In particular, it can't be a topCTS
1691 // resulting from mergeing two difference pcCTS's since the verifier
1692 // would have rejected any use of such a merge.
1693 } else {
1694 push(out1); // handle val/init conflict
1695 }
1696 loc_no++;
1697 }
1698 }
1699
1700 void GenerateOopMap::ppdupswap(int poplen, const char *out) {
1701 CellTypeState actual[5];
1702 assert(poplen < 5, "this must be less than length of actual vector");
1703
1704 // Pop all arguments.
1705 for (int i = 0; i < poplen; i++) {
1706 actual[i] = pop();
1707 }
1708 // Field _state is uninitialized when calling push.
1709 for (int i = poplen; i < 5; i++) {
1710 actual[i] = CellTypeState::uninit;
1711 }
1712
1713 // put them back
1714 char push_ch = *out++;
1715 while (push_ch != '\0') {
1716 int idx = push_ch - '1';
1717 assert(idx >= 0 && idx < poplen, "wrong arguments");
1718 push(actual[idx]);
1719 push_ch = *out++;
1720 }
1721 }
1722
1723 void GenerateOopMap::ppop1(CellTypeState out) {
1724 CellTypeState actual = pop();
1725 check_type(out, actual);
1726 }
1727
1728 void GenerateOopMap::ppop(CellTypeState *out) {
1729 while (!(*out).is_bottom()) {
1730 ppop1(*out++);
1731 }
1732 }
1733
1734 void GenerateOopMap::ppush1(CellTypeState in) {
1735 assert(in.is_reference() || in.is_value(), "sanity check");
1736 push(in);
1737 }
1738
1739 void GenerateOopMap::ppush(CellTypeState *in) {
1740 while (!(*in).is_bottom()) {
1741 ppush1(*in++);
1742 }
1743 }
1744
1745 void GenerateOopMap::pp(CellTypeState *in, CellTypeState *out) {
1746 ppop(in);
1747 ppush(out);
1748 }
1749
1750 void GenerateOopMap::pp_new_ref(CellTypeState *in, int bci) {
1751 ppop(in);
1752 ppush1(CellTypeState::make_line_ref(bci));
1753 }
1754
1755 void GenerateOopMap::ppop_any(int poplen) {
1756 if (_stack_top >= poplen) {
1757 _stack_top -= poplen;
1758 } else {
1759 verify_error("stack underflow");
1760 }
1761 }
1762
1763 // Replace all occurrences of the state 'match' with the state 'replace'
1764 // in our current state vector.
1765 void GenerateOopMap::replace_all_CTS_matches(CellTypeState match,
1766 CellTypeState replace) {
1767 int i;
1768 int len = _max_locals + _stack_top;
1769 bool change = false;
1770
1771 for (i = len - 1; i >= 0; i--) {
1772 if (match.equal(_state[i])) {
1773 _state[i] = replace;
1774 }
1775 }
1776
1777 if (_monitor_top > 0) {
1778 int base = _max_locals + _max_stack;
1779 len = base + _monitor_top;
1780 for (i = len - 1; i >= base; i--) {
1781 if (match.equal(_state[i])) {
1782 _state[i] = replace;
1783 }
1784 }
1785 }
1786 }
1787
1788 void GenerateOopMap::do_checkcast() {
1789 CellTypeState actual = pop();
1790 check_type(refCTS, actual);
1791 push(actual);
1792 }
1793
1794 void GenerateOopMap::do_monitorenter(int bci) {
1795 CellTypeState actual = pop();
1796 if (_monitor_top == bad_monitors) {
1797 return;
1798 }
1799
1800 // Bail out when we get repeated locks on an identical monitor. This case
1801 // isn't too hard to handle and can be made to work if supporting nested
1802 // redundant synchronized statements becomes a priority.
1803 //
1804 // See also "Note" in do_monitorexit(), below.
1805 if (actual.is_lock_reference()) {
1806 _monitor_top = bad_monitors;
1807 _monitor_safe = false;
1808
1809 if (log_is_enabled(Info, monitormismatch)) {
1810 report_monitor_mismatch("nested redundant lock -- bailout...");
1811 }
1812 return;
1813 }
1814
1815 CellTypeState lock = CellTypeState::make_lock_ref(bci);
1816 check_type(refCTS, actual);
1817 if (!actual.is_info_top()) {
1818 replace_all_CTS_matches(actual, lock);
1819 monitor_push(lock);
1820 }
1821 }
1822
1823 void GenerateOopMap::do_monitorexit(int bci) {
1824 CellTypeState actual = pop();
1825 if (_monitor_top == bad_monitors) {
1826 return;
1827 }
1828 check_type(refCTS, actual);
1829 CellTypeState expected = monitor_pop();
1830 if (!actual.is_lock_reference() || !expected.equal(actual)) {
1831 // The monitor we are exiting is not verifiably the one
1832 // on the top of our monitor stack. This causes a monitor
1833 // mismatch.
1834 _monitor_top = bad_monitors;
1835 _monitor_safe = false;
1836
1837 // We need to mark this basic block as changed so that
1838 // this monitorexit will be visited again. We need to
1839 // do this to ensure that we have accounted for the
1840 // possibility that this bytecode will throw an
1841 // exception.
1842 BasicBlock* bb = get_basic_block_containing(bci);
1843 guarantee(bb != nullptr, "no basic block for bci");
1844 bb->set_changed(true);
1845 bb->_monitor_top = bad_monitors;
1846
1847 if (log_is_enabled(Info, monitormismatch)) {
1848 report_monitor_mismatch("improper monitor pair");
1849 }
1850 } else {
1851 // This code is a fix for the case where we have repeated
1852 // locking of the same object in straightline code. We clear
1853 // out the lock when it is popped from the monitor stack
1854 // and replace it with an unobtrusive reference value that can
1855 // be locked again.
1856 //
1857 // Note: when generateOopMap is fixed to properly handle repeated,
1858 // nested, redundant locks on the same object, then this
1859 // fix will need to be removed at that time.
1860 replace_all_CTS_matches(actual, CellTypeState::make_line_ref(bci));
1861 }
1862 }
1863
1864 void GenerateOopMap::do_return_monitor_check() {
1865 if (_monitor_top > 0) {
1866 // The monitor stack must be empty when we leave the method
1867 // for the monitors to be properly matched.
1868 _monitor_safe = false;
1869
1870 // Since there are no successors to the *return bytecode, it
1871 // isn't necessary to set _monitor_top to bad_monitors.
1872
1873 if (log_is_enabled(Info, monitormismatch)) {
1874 report_monitor_mismatch("non-empty monitor stack at return");
1875 }
1876 }
1877 }
1878
1879 void GenerateOopMap::do_jsr(int targ_bci) {
1880 push(CellTypeState::make_addr(targ_bci));
1881 }
1882
1883
1884
1885 void GenerateOopMap::do_ldc(int bci) {
1886 Bytecode_loadconstant ldc(methodHandle(Thread::current(), method()), bci);
1887 ConstantPool* cp = method()->constants();
1888 constantTag tag = cp->tag_at(ldc.pool_index()); // idx is index in resolved_references
1889 BasicType bt = ldc.result_type();
1890 #ifdef ASSERT
1891 BasicType tag_bt = (tag.is_dynamic_constant() || tag.is_dynamic_constant_in_error()) ? bt : tag.basic_type();
1892 assert(bt == tag_bt, "same result");
1893 #endif
1894 CellTypeState cts;
1895 if (is_reference_type(bt)) { // could be T_ARRAY with condy
1896 assert(!tag.is_string_index() && !tag.is_klass_index(), "Unexpected index tag");
1897 cts = CellTypeState::make_line_ref(bci);
1898 } else {
1899 cts = valCTS;
1900 }
1901 ppush1(cts);
1902 }
1903
1904 void GenerateOopMap::do_multianewarray(int dims, int bci) {
1905 assert(dims >= 1, "sanity check");
1906 for(int i = dims -1; i >=0; i--) {
1907 ppop1(valCTS);
1908 }
1909 ppush1(CellTypeState::make_line_ref(bci));
1910 }
1911
1912 void GenerateOopMap::do_astore(int idx) {
1913 CellTypeState r_or_p = pop();
1914 if (!r_or_p.is_address() && !r_or_p.is_reference()) {
1915 // We actually expected ref or pc, but we only report that we expected a ref. It does not
1916 // really matter (at least for now)
1917 verify_error("wrong type on stack (found: %c, expected: {pr})", r_or_p.to_char());
1918 return;
1919 }
1920 set_var(idx, r_or_p);
1921 }
1922
1923 // Copies bottom/zero terminated CTS string from "src" into "dst".
1924 // Does NOT terminate with a bottom. Returns the number of cells copied.
1925 int GenerateOopMap::copy_cts(CellTypeState *dst, CellTypeState *src) {
1926 int idx = 0;
1927 while (!src[idx].is_bottom()) {
1928 dst[idx] = src[idx];
1929 idx++;
1930 }
1931 return idx;
1932 }
1933
1934 void GenerateOopMap::do_field(int is_get, int is_static, int idx, int bci, Bytecodes::Code bc) {
1935 // Dig up signature for field in constant pool
1936 ConstantPool* cp = method()->constants();
1937 int nameAndTypeIdx = cp->name_and_type_ref_index_at(idx, bc);
1938 int signatureIdx = cp->signature_ref_index_at(nameAndTypeIdx);
1939 Symbol* signature = cp->symbol_at(signatureIdx);
1940
1941 CellTypeState temp[4];
1942 CellTypeState *eff = signature_to_effect(signature, bci, temp);
1943
1944 CellTypeState in[4];
1945 CellTypeState *out;
1946 int i = 0;
1947
1948 if (is_get) {
1949 out = eff;
1950 } else {
1951 out = epsilonCTS;
1952 i = copy_cts(in, eff);
1953 }
1954 if (!is_static) in[i++] = CellTypeState::ref;
1955 in[i] = CellTypeState::bottom;
1956 assert(i<=3, "sanity check");
1957 pp(in, out);
1958 }
1959
1960 void GenerateOopMap::do_method(int is_static, int is_interface, int idx, int bci, Bytecodes::Code bc) {
1961 // Dig up signature for field in constant pool
1962 ConstantPool* cp = _method->constants();
1963 Symbol* signature = cp->signature_ref_at(idx, bc);
1964
1965 // Parse method signature
1966 CellTypeState out[4];
1967 CellTypeState in[MAXARGSIZE+1]; // Includes result
1968 ComputeCallStack cse(signature);
1969
1970 // Compute return type
1971 int res_length= cse.compute_for_returntype(out);
1972
1973 // Temporary hack.
1974 if (out[0].equal(CellTypeState::ref) && out[1].equal(CellTypeState::bottom)) {
1975 out[0] = CellTypeState::make_line_ref(bci);
1976 }
1977
1978 assert(res_length<=4, "max value should be vv");
1979
1980 // Compute arguments
1981 int arg_length = cse.compute_for_parameters(is_static != 0, in);
1982 assert(arg_length<=MAXARGSIZE, "too many locals");
1983
1984 // Pop arguments
1985 for (int i = arg_length - 1; i >= 0; i--) ppop1(in[i]);// Do args in reverse order.
1986
1987 // Report results
1988 if (_report_result_for_send == true) {
1989 fill_stackmap_for_opcodes(_itr_send, vars(), stack(), _stack_top);
1990 _report_result_for_send = false;
1991 }
1992
1993 // Push return address
1994 ppush(out);
1995 }
1996
1997 // This is used to parse the signature for fields, since they are very simple...
1998 CellTypeState *GenerateOopMap::signature_to_effect(const Symbol* sig, int bci, CellTypeState *out) {
1999 // Object and array
2000 BasicType bt = Signature::basic_type(sig);
2001 if (is_reference_type(bt)) {
2002 out[0] = CellTypeState::make_line_ref(bci);
2003 out[1] = CellTypeState::bottom;
2004 return out;
2005 }
2006 if (is_double_word_type(bt)) return vvCTS; // Long and Double
2007 if (bt == T_VOID) return epsilonCTS; // Void
2008 return vCTS; // Otherwise
2009 }
2010
2011 uint64_t GenerateOopMap::_total_byte_count = 0;
2012 elapsedTimer GenerateOopMap::_total_oopmap_time;
2013
2014 // This function assumes "bcs" is at a "ret" instruction and that the vars
2015 // state is valid for that instruction. Furthermore, the ret instruction
2016 // must be the last instruction in "bb" (we store information about the
2017 // "ret" in "bb").
2018 void GenerateOopMap::ret_jump_targets_do(BytecodeStream *bcs, jmpFct_t jmpFct, int varNo, int *data) {
2019 CellTypeState ra = vars()[varNo];
2020 if (!ra.is_good_address()) {
2021 verify_error("ret returns from two jsr subroutines?");
2022 return;
2023 }
2024 int target = ra.get_info();
2025
2026 RetTableEntry* rtEnt = _rt.find_jsrs_for_target(target);
2027 int bci = bcs->bci();
2028 for (int i = 0; i < rtEnt->nof_jsrs(); i++) {
2029 int target_bci = rtEnt->jsrs(i);
2030 // Make sure a jrtRet does not set the changed bit for dead basicblock.
2031 BasicBlock* jsr_bb = get_basic_block_containing(target_bci - 1);
2032 debug_only(BasicBlock* target_bb = &jsr_bb[1];)
2033 assert(target_bb == get_basic_block_at(target_bci), "wrong calc. of successor basicblock");
2034 bool alive = jsr_bb->is_alive();
2035 if (TraceNewOopMapGeneration) {
2036 tty->print("pc = %d, ret -> %d alive: %s\n", bci, target_bci, alive ? "true" : "false");
2037 }
2038 if (alive) jmpFct(this, target_bci, data);
2039 }
2040 }
2041
2042 //
2043 // Debug method
2044 //
2045 char* GenerateOopMap::state_vec_to_string(CellTypeState* vec, int len) {
2046 #ifdef ASSERT
2047 int checklen = MAX3(_max_locals, _max_stack, _max_monitors) + 1;
2048 assert(len < checklen, "state_vec_buf overflow");
2049 #endif
2050 for (int i = 0; i < len; i++) _state_vec_buf[i] = vec[i].to_char();
2051 _state_vec_buf[len] = 0;
2052 return _state_vec_buf;
2053 }
2054
2055 void GenerateOopMap::print_time() {
2056 tty->print_cr ("Accumulated oopmap times:");
2057 tty->print_cr ("---------------------------");
2058 tty->print_cr (" Total : %3.3f sec.", GenerateOopMap::_total_oopmap_time.seconds());
2059 tty->print_cr (" (%3.0f bytecodes per sec) ",
2060 (double)GenerateOopMap::_total_byte_count / GenerateOopMap::_total_oopmap_time.seconds());
2061 }
2062
2063 //
2064 // ============ Main Entry Point ===========
2065 //
2066 GenerateOopMap::GenerateOopMap(const methodHandle& method) {
2067 // We have to initialize all variables here, that can be queried directly
2068 _method = method;
2069 _max_locals=0;
2070 _init_vars = nullptr;
2071
2072 #ifndef PRODUCT
2073 // If we are doing a detailed trace, include the regular trace information.
2074 if (TraceNewOopMapGenerationDetailed) {
2075 TraceNewOopMapGeneration = true;
2076 }
2077 #endif
2078 }
2079
2080 bool GenerateOopMap::compute_map(Thread* current) {
2081 #ifndef PRODUCT
2082 if (TimeOopMap2) {
2083 method()->print_short_name(tty);
2084 tty->print(" ");
2085 }
2086 if (TimeOopMap) {
2087 _total_byte_count += method()->code_size();
2088 }
2089 #endif
2090 TraceTime t_single("oopmap time", TimeOopMap2);
2091 TraceTime t_all(nullptr, &_total_oopmap_time, TimeOopMap);
2092
2093 // Initialize values
2094 _got_error = false;
2095 _conflict = false;
2096 _max_locals = method()->max_locals();
2097 _max_stack = method()->max_stack();
2098 _has_exceptions = (method()->has_exception_handler());
2099 _nof_refval_conflicts = 0;
2100 _init_vars = new GrowableArray<intptr_t>(5); // There are seldom more than 5 init_vars
2101 _report_result = false;
2102 _report_result_for_send = false;
2103 _new_var_map = nullptr;
2104 _ret_adr_tos = new GrowableArray<int>(5); // 5 seems like a good number;
2105 _did_rewriting = false;
2106 _did_relocation = false;
2107
2108 if (TraceNewOopMapGeneration) {
2109 tty->print("Method name: %s\n", method()->name()->as_C_string());
2110 if (Verbose) {
2111 _method->print_codes();
2112 tty->print_cr("Exception table:");
2113 ExceptionTable excps(method());
2114 for(int i = 0; i < excps.length(); i ++) {
2115 tty->print_cr("[%d - %d] -> %d",
2116 excps.start_pc(i), excps.end_pc(i), excps.handler_pc(i));
2117 }
2118 }
2119 }
2120
2121 // if no code - do nothing
2122 // compiler needs info
2123 if (method()->code_size() == 0 || _max_locals + method()->max_stack() == 0) {
2124 fill_stackmap_prolog(0);
2125 fill_stackmap_epilog();
2126 return true;
2127 }
2128 // Step 1: Compute all jump targets and their return value
2129 if (!_got_error)
2130 _rt.compute_ret_table(_method);
2131
2132 // Step 2: Find all basic blocks and count GC points
2133 if (!_got_error)
2134 mark_bbheaders_and_count_gc_points();
2135
2136 // Step 3: Calculate stack maps
2137 if (!_got_error)
2138 do_interpretation();
2139
2140 // Step 4:Return results
2141 if (!_got_error && report_results())
2142 report_result();
2143
2144 return !_got_error;
2145 }
2146
2147 // Error handling methods
2148 //
2149 // If we compute from a suitable JavaThread then we create an exception for the GenerateOopMap
2150 // calling code to retrieve (via exception()) and throw if desired (in most cases errors are ignored).
2151 // Otherwise it is considered a fatal error to hit malformed bytecode.
2152 void GenerateOopMap::error_work(const char *format, va_list ap) {
2153 _got_error = true;
2154 char msg_buffer[512];
2155 os::vsnprintf(msg_buffer, sizeof(msg_buffer), format, ap);
2156 // Append method name
2157 char msg_buffer2[512];
2158 os::snprintf(msg_buffer2, sizeof(msg_buffer2), "%s in method %s", msg_buffer, method()->name()->as_C_string());
2159 Thread* current = Thread::current();
2160 if (current->can_call_java()) {
2161 _exception = Exceptions::new_exception(JavaThread::cast(current),
2162 vmSymbols::java_lang_LinkageError(),
2163 msg_buffer2);
2164 } else {
2165 fatal("%s", msg_buffer2);
2166 }
2167 }
2168
2169 void GenerateOopMap::report_error(const char *format, ...) {
2170 va_list ap;
2171 va_start(ap, format);
2172 error_work(format, ap);
2173 }
2174
2175 void GenerateOopMap::verify_error(const char *format, ...) {
2176 // We do not distinguish between different types of errors for verification
2177 // errors. Let the verifier give a better message.
2178 report_error("Illegal class file encountered. Try running with -Xverify:all");
2179 }
2180
2181 //
2182 // Report result opcodes
2183 //
2184 void GenerateOopMap::report_result() {
2185
2186 if (TraceNewOopMapGeneration) tty->print_cr("Report result pass");
2187
2188 // We now want to report the result of the parse
2189 _report_result = true;
2190
2191 // Prolog code
2192 fill_stackmap_prolog(_gc_points);
2193
2194 // Mark everything changed, then do one interpretation pass.
2195 for (int i = 0; i<_bb_count; i++) {
2196 if (_basic_blocks[i].is_reachable()) {
2197 _basic_blocks[i].set_changed(true);
2198 interp_bb(&_basic_blocks[i]);
2199 }
2200 }
2201
2202 // Note: Since we are skipping dead-code when we are reporting results, then
2203 // the no. of encountered gc-points might be fewer than the previously number
2204 // we have counted. (dead-code is a pain - it should be removed before we get here)
2205 fill_stackmap_epilog();
2206
2207 // Report initvars
2208 fill_init_vars(_init_vars);
2209
2210 _report_result = false;
2211 }
2212
2213 void GenerateOopMap::result_for_basicblock(int bci) {
2214 if (TraceNewOopMapGeneration) tty->print_cr("Report result pass for basicblock");
2215
2216 // We now want to report the result of the parse
2217 _report_result = true;
2218
2219 // Find basicblock and report results
2220 BasicBlock* bb = get_basic_block_containing(bci);
2221 guarantee(bb != nullptr, "no basic block for bci");
2222 assert(bb->is_reachable(), "getting result from unreachable basicblock");
2223 bb->set_changed(true);
2224 interp_bb(bb);
2225 }
2226
2227 //
2228 // Conflict handling code
2229 //
2230
2231 void GenerateOopMap::record_refval_conflict(int varNo) {
2232 assert(varNo>=0 && varNo< _max_locals, "index out of range");
2233
2234 if (TraceOopMapRewrites) {
2235 tty->print("### Conflict detected (local no: %d)\n", varNo);
2236 }
2237
2238 if (!_new_var_map) {
2239 _new_var_map = NEW_RESOURCE_ARRAY(int, _max_locals);
2240 for (int k = 0; k < _max_locals; k++) _new_var_map[k] = k;
2241 }
2242
2243 if ( _new_var_map[varNo] == varNo) {
2244 // Check if max. number of locals has been reached
2245 if (_max_locals + _nof_refval_conflicts >= MAX_LOCAL_VARS) {
2246 report_error("Rewriting exceeded local variable limit");
2247 return;
2248 }
2249 _new_var_map[varNo] = _max_locals + _nof_refval_conflicts;
2250 _nof_refval_conflicts++;
2251 }
2252 }
2253
2254 void GenerateOopMap::rewrite_refval_conflicts()
2255 {
2256 // We can get here two ways: Either a rewrite conflict was detected, or
2257 // an uninitialize reference was detected. In the second case, we do not
2258 // do any rewriting, we just want to recompute the reference set with the
2259 // new information
2260
2261 int nof_conflicts = 0; // Used for debugging only
2262
2263 if ( _nof_refval_conflicts == 0 )
2264 return;
2265
2266 // Check if rewrites are allowed in this parse.
2267 if (!allow_rewrites()) {
2268 fatal("Rewriting method not allowed at this stage");
2269 }
2270
2271
2272 // Tracing flag
2273 _did_rewriting = true;
2274
2275 if (TraceOopMapRewrites) {
2276 tty->print_cr("ref/value conflict for method %s - bytecodes are getting rewritten", method()->name()->as_C_string());
2277 method()->print();
2278 method()->print_codes();
2279 }
2280
2281 assert(_new_var_map!=nullptr, "nothing to rewrite");
2282 assert(_conflict==true, "We should not be here");
2283
2284 compute_ret_adr_at_TOS();
2285 if (!_got_error) {
2286 for (int k = 0; k < _max_locals && !_got_error; k++) {
2287 if (_new_var_map[k] != k) {
2288 if (TraceOopMapRewrites) {
2289 tty->print_cr("Rewriting: %d -> %d", k, _new_var_map[k]);
2290 }
2291 rewrite_refval_conflict(k, _new_var_map[k]);
2292 if (_got_error) return;
2293 nof_conflicts++;
2294 }
2295 }
2296 }
2297
2298 assert(nof_conflicts == _nof_refval_conflicts, "sanity check");
2299
2300 // Adjust the number of locals
2301 method()->set_max_locals(_max_locals+_nof_refval_conflicts);
2302 _max_locals += _nof_refval_conflicts;
2303
2304 // That was that...
2305 _new_var_map = nullptr;
2306 _nof_refval_conflicts = 0;
2307 }
2308
2309 void GenerateOopMap::rewrite_refval_conflict(int from, int to) {
2310 bool startOver;
2311 do {
2312 // Make sure that the BytecodeStream is constructed in the loop, since
2313 // during rewriting a new method is going to be used, and the next time
2314 // around we want to use that.
2315 BytecodeStream bcs(_method);
2316 startOver = false;
2317
2318 while( !startOver && !_got_error &&
2319 // test bcs in case method changed and it became invalid
2320 bcs.next() >=0) {
2321 startOver = rewrite_refval_conflict_inst(&bcs, from, to);
2322 }
2323 } while (startOver && !_got_error);
2324 }
2325
2326 /* If the current instruction is one that uses local variable "from"
2327 in a ref way, change it to use "to". There's a subtle reason why we
2328 renumber the ref uses and not the non-ref uses: non-ref uses may be
2329 2 slots wide (double, long) which would necessitate keeping track of
2330 whether we should add one or two variables to the method. If the change
2331 affected the width of some instruction, returns "TRUE"; otherwise, returns "FALSE".
2332 Another reason for moving ref's value is for solving (addr, ref) conflicts, which
2333 both uses aload/astore methods.
2334 */
2335 bool GenerateOopMap::rewrite_refval_conflict_inst(BytecodeStream *itr, int from, int to) {
2336 Bytecodes::Code bc = itr->code();
2337 int index;
2338 int bci = itr->bci();
2339
2340 if (is_aload(itr, &index) && index == from) {
2341 if (TraceOopMapRewrites) {
2342 tty->print_cr("Rewriting aload at bci: %d", bci);
2343 }
2344 return rewrite_load_or_store(itr, Bytecodes::_aload, Bytecodes::_aload_0, to);
2345 }
2346
2347 if (is_astore(itr, &index) && index == from) {
2348 if (!stack_top_holds_ret_addr(bci)) {
2349 if (TraceOopMapRewrites) {
2350 tty->print_cr("Rewriting astore at bci: %d", bci);
2351 }
2352 return rewrite_load_or_store(itr, Bytecodes::_astore, Bytecodes::_astore_0, to);
2353 } else {
2354 if (TraceOopMapRewrites) {
2355 tty->print_cr("Suppress rewriting of astore at bci: %d", bci);
2356 }
2357 }
2358 }
2359
2360 return false;
2361 }
2362
2363 // The argument to this method is:
2364 // bc : Current bytecode
2365 // bcN : either _aload or _astore
2366 // bc0 : either _aload_0 or _astore_0
2367 bool GenerateOopMap::rewrite_load_or_store(BytecodeStream *bcs, Bytecodes::Code bcN, Bytecodes::Code bc0, unsigned int varNo) {
2368 assert(bcN == Bytecodes::_astore || bcN == Bytecodes::_aload, "wrong argument (bcN)");
2369 assert(bc0 == Bytecodes::_astore_0 || bc0 == Bytecodes::_aload_0, "wrong argument (bc0)");
2370 int ilen = Bytecodes::length_at(_method(), bcs->bcp());
2371 int newIlen;
2372
2373 if (ilen == 4) {
2374 // Original instruction was wide; keep it wide for simplicity
2375 newIlen = 4;
2376 } else if (varNo < 4)
2377 newIlen = 1;
2378 else if (varNo >= 256)
2379 newIlen = 4;
2380 else
2381 newIlen = 2;
2382
2383 // If we need to relocate in order to patch the byte, we
2384 // do the patching in a temp. buffer, that is passed to the reloc.
2385 // The patching of the bytecode stream is then done by the Relocator.
2386 // This is necessary, since relocating the instruction at a certain bci, might
2387 // also relocate that instruction, e.g., if a _goto before it gets widen to a _goto_w.
2388 // Hence, we do not know which bci to patch after relocation.
2389
2390 assert(newIlen <= 4, "sanity check");
2391 u_char inst_buffer[4]; // Max. instruction size is 4.
2392 address bcp;
2393
2394 if (newIlen != ilen) {
2395 // Relocation needed do patching in temp. buffer
2396 bcp = (address)inst_buffer;
2397 } else {
2398 bcp = _method->bcp_from(bcs->bci());
2399 }
2400
2401 // Patch either directly in Method* or in temp. buffer
2402 if (newIlen == 1) {
2403 assert(varNo < 4, "varNo too large");
2404 *bcp = (u1)(bc0 + varNo);
2405 } else if (newIlen == 2) {
2406 assert(varNo < 256, "2-byte index needed!");
2407 *(bcp + 0) = bcN;
2408 *(bcp + 1) = (u1)varNo;
2409 } else {
2410 assert(newIlen == 4, "Wrong instruction length");
2411 *(bcp + 0) = Bytecodes::_wide;
2412 *(bcp + 1) = bcN;
2413 Bytes::put_Java_u2(bcp+2, (u2)varNo);
2414 }
2415
2416 if (newIlen != ilen) {
2417 expand_current_instr(bcs->bci(), ilen, newIlen, inst_buffer);
2418 }
2419
2420
2421 return (newIlen != ilen);
2422 }
2423
2424 class RelocCallback : public RelocatorListener {
2425 private:
2426 GenerateOopMap* _gom;
2427 public:
2428 RelocCallback(GenerateOopMap* gom) { _gom = gom; };
2429
2430 // Callback method
2431 virtual void relocated(int bci, int delta, int new_code_length) {
2432 _gom->update_basic_blocks (bci, delta, new_code_length);
2433 _gom->update_ret_adr_at_TOS(bci, delta);
2434 _gom->_rt.update_ret_table (bci, delta);
2435 }
2436 };
2437
2438 // Returns true if expanding was successful. Otherwise, reports an error and
2439 // returns false.
2440 void GenerateOopMap::expand_current_instr(int bci, int ilen, int newIlen, u_char inst_buffer[]) {
2441 JavaThread* THREAD = JavaThread::current(); // For exception macros.
2442 RelocCallback rcb(this);
2443 Relocator rc(_method, &rcb);
2444 methodHandle m= rc.insert_space_at(bci, newIlen, inst_buffer, THREAD);
2445 if (m.is_null() || HAS_PENDING_EXCEPTION) {
2446 report_error("could not rewrite method - exception occurred or bytecode buffer overflow");
2447 return;
2448 }
2449
2450 // Relocator returns a new method.
2451 _did_relocation = true;
2452 _method = m;
2453 }
2454
2455
2456 bool GenerateOopMap::is_astore(BytecodeStream *itr, int *index) {
2457 Bytecodes::Code bc = itr->code();
2458 switch(bc) {
2459 case Bytecodes::_astore_0:
2460 case Bytecodes::_astore_1:
2461 case Bytecodes::_astore_2:
2462 case Bytecodes::_astore_3:
2463 *index = bc - Bytecodes::_astore_0;
2464 return true;
2465 case Bytecodes::_astore:
2466 *index = itr->get_index();
2467 return true;
2468 default:
2469 return false;
2470 }
2471 }
2472
2473 bool GenerateOopMap::is_aload(BytecodeStream *itr, int *index) {
2474 Bytecodes::Code bc = itr->code();
2475 switch(bc) {
2476 case Bytecodes::_aload_0:
2477 case Bytecodes::_aload_1:
2478 case Bytecodes::_aload_2:
2479 case Bytecodes::_aload_3:
2480 *index = bc - Bytecodes::_aload_0;
2481 return true;
2482
2483 case Bytecodes::_aload:
2484 *index = itr->get_index();
2485 return true;
2486
2487 default:
2488 return false;
2489 }
2490 }
2491
2492
2493 // Return true iff the top of the operand stack holds a return address at
2494 // the current instruction
2495 bool GenerateOopMap::stack_top_holds_ret_addr(int bci) {
2496 for(int i = 0; i < _ret_adr_tos->length(); i++) {
2497 if (_ret_adr_tos->at(i) == bci)
2498 return true;
2499 }
2500
2501 return false;
2502 }
2503
2504 void GenerateOopMap::compute_ret_adr_at_TOS() {
2505 assert(_ret_adr_tos != nullptr, "must be initialized");
2506 _ret_adr_tos->clear();
2507
2508 for (int i = 0; i < bb_count(); i++) {
2509 BasicBlock* bb = &_basic_blocks[i];
2510
2511 // Make sure to only check basicblocks that are reachable
2512 if (bb->is_reachable()) {
2513
2514 // For each Basic block we check all instructions
2515 BytecodeStream bcs(_method);
2516 bcs.set_interval(bb->_bci, next_bb_start_pc(bb));
2517
2518 restore_state(bb);
2519
2520 while (bcs.next()>=0 && !_got_error) {
2521 // TDT: should this be is_good_address() ?
2522 if (_stack_top > 0 && stack()[_stack_top-1].is_address()) {
2523 _ret_adr_tos->append(bcs.bci());
2524 if (TraceNewOopMapGeneration) {
2525 tty->print_cr("Ret_adr TOS at bci: %d", bcs.bci());
2526 }
2527 }
2528 interp1(&bcs);
2529 }
2530 }
2531 }
2532 }
2533
2534 void GenerateOopMap::update_ret_adr_at_TOS(int bci, int delta) {
2535 for(int i = 0; i < _ret_adr_tos->length(); i++) {
2536 int v = _ret_adr_tos->at(i);
2537 if (v > bci) _ret_adr_tos->at_put(i, v + delta);
2538 }
2539 }
2540
2541 // ===================================================================
2542
2543 #ifndef PRODUCT
2544 int ResolveOopMapConflicts::_nof_invocations = 0;
2545 int ResolveOopMapConflicts::_nof_rewrites = 0;
2546 int ResolveOopMapConflicts::_nof_relocations = 0;
2547 #endif
2548
2549 methodHandle ResolveOopMapConflicts::do_potential_rewrite(TRAPS) {
2550 if (!compute_map(THREAD)) {
2551 THROW_HANDLE_(exception(), methodHandle());
2552 }
2553
2554 #ifndef PRODUCT
2555 // Tracking and statistics
2556 if (PrintRewrites) {
2557 _nof_invocations++;
2558 if (did_rewriting()) {
2559 _nof_rewrites++;
2560 if (did_relocation()) _nof_relocations++;
2561 tty->print("Method was rewritten %s: ", (did_relocation()) ? "and relocated" : "");
2562 method()->print_value(); tty->cr();
2563 tty->print_cr("Cand.: %d rewrts: %d (%d%%) reloc.: %d (%d%%)",
2564 _nof_invocations,
2565 _nof_rewrites, (_nof_rewrites * 100) / _nof_invocations,
2566 _nof_relocations, (_nof_relocations * 100) / _nof_invocations);
2567 }
2568 }
2569 #endif
2570 return methodHandle(THREAD, method());
2571 }