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 LogStream ls(Log(monitormismatch)::info());
1284 ls.print("Monitor mismatch in method ");
1285 method()->print_short_name(&ls);
1286 ls.print_cr(": %s", msg);
1287 }
1288
1289 void GenerateOopMap::print_states(outputStream *os,
1290 CellTypeState* vec, int num) {
1291 for (int i = 0; i < num; i++) {
1292 vec[i].print(tty);
1293 }
1294 }
1295
1296 // Print the state values at the current bytecode.
1297 void GenerateOopMap::print_current_state(outputStream *os,
1298 BytecodeStream *currentBC,
1299 bool detailed) {
1300 if (detailed) {
1301 os->print(" %4d vars = ", currentBC->bci());
1302 print_states(os, vars(), _max_locals);
1303 os->print(" %s", Bytecodes::name(currentBC->code()));
1304 } else {
1305 os->print(" %4d vars = '%s' ", currentBC->bci(), state_vec_to_string(vars(), _max_locals));
1306 os->print(" stack = '%s' ", state_vec_to_string(stack(), _stack_top));
1307 if (_monitor_top != bad_monitors) {
1308 os->print(" monitors = '%s' \t%s", state_vec_to_string(monitors(), _monitor_top), Bytecodes::name(currentBC->code()));
1309 } else {
1310 os->print(" [bad monitor stack]");
1311 }
1312 }
1313
1314 switch(currentBC->code()) {
1315 case Bytecodes::_invokevirtual:
1316 case Bytecodes::_invokespecial:
1317 case Bytecodes::_invokestatic:
1318 case Bytecodes::_invokedynamic:
1319 case Bytecodes::_invokeinterface: {
1320 int idx = currentBC->has_index_u4() ? currentBC->get_index_u4() : currentBC->get_index_u2();
1321 ConstantPool* cp = method()->constants();
1322 int nameAndTypeIdx = cp->name_and_type_ref_index_at(idx, currentBC->code());
1323 int signatureIdx = cp->signature_ref_index_at(nameAndTypeIdx);
1324 Symbol* signature = cp->symbol_at(signatureIdx);
1325 os->print("%s", signature->as_C_string());
1326 }
1327 default:
1328 break;
1329 }
1330
1331 if (detailed) {
1332 os->cr();
1333 os->print(" stack = ");
1334 print_states(os, stack(), _stack_top);
1335 os->cr();
1336 if (_monitor_top != bad_monitors) {
1337 os->print(" monitors = ");
1338 print_states(os, monitors(), _monitor_top);
1339 } else {
1340 os->print(" [bad monitor stack]");
1341 }
1342 }
1343
1344 os->cr();
1345 }
1346
1347 // Sets the current state to be the state after executing the
1348 // current instruction, starting in the current state.
1349 void GenerateOopMap::interp1(BytecodeStream *itr) {
1350 if (TraceNewOopMapGeneration) {
1351 print_current_state(tty, itr, TraceNewOopMapGenerationDetailed);
1352 }
1353
1354 // Should we report the results? Result is reported *before* the instruction at the current bci is executed.
1355 // However, not for calls. For calls we do not want to include the arguments, so we postpone the reporting until
1356 // they have been popped (in method ppl).
1357 if (_report_result == true) {
1358 switch(itr->code()) {
1359 case Bytecodes::_invokevirtual:
1360 case Bytecodes::_invokespecial:
1361 case Bytecodes::_invokestatic:
1362 case Bytecodes::_invokedynamic:
1363 case Bytecodes::_invokeinterface:
1364 _itr_send = itr;
1365 _report_result_for_send = true;
1366 break;
1367 default:
1368 fill_stackmap_for_opcodes(itr, vars(), stack(), _stack_top);
1369 break;
1370 }
1371 }
1372
1373 // abstract interpretation of current opcode
1374 switch(itr->code()) {
1375 case Bytecodes::_nop: break;
1376 case Bytecodes::_goto: break;
1377 case Bytecodes::_goto_w: break;
1378 case Bytecodes::_iinc: break;
1379 case Bytecodes::_return: do_return_monitor_check();
1380 break;
1381
1382 case Bytecodes::_aconst_null:
1383 case Bytecodes::_new: ppush1(CellTypeState::make_line_ref(itr->bci()));
1384 break;
1385
1386 case Bytecodes::_iconst_m1:
1387 case Bytecodes::_iconst_0:
1388 case Bytecodes::_iconst_1:
1389 case Bytecodes::_iconst_2:
1390 case Bytecodes::_iconst_3:
1391 case Bytecodes::_iconst_4:
1392 case Bytecodes::_iconst_5:
1393 case Bytecodes::_fconst_0:
1394 case Bytecodes::_fconst_1:
1395 case Bytecodes::_fconst_2:
1396 case Bytecodes::_bipush:
1397 case Bytecodes::_sipush: ppush1(valCTS); break;
1398
1399 case Bytecodes::_lconst_0:
1400 case Bytecodes::_lconst_1:
1401 case Bytecodes::_dconst_0:
1402 case Bytecodes::_dconst_1: ppush(vvCTS); break;
1403
1404 case Bytecodes::_ldc2_w: ppush(vvCTS); break;
1405
1406 case Bytecodes::_ldc: // fall through:
1407 case Bytecodes::_ldc_w: do_ldc(itr->bci()); break;
1408
1409 case Bytecodes::_iload:
1410 case Bytecodes::_fload: ppload(vCTS, itr->get_index()); break;
1411
1412 case Bytecodes::_lload:
1413 case Bytecodes::_dload: ppload(vvCTS,itr->get_index()); break;
1414
1415 case Bytecodes::_aload: ppload(rCTS, itr->get_index()); break;
1416
1417 case Bytecodes::_iload_0:
1418 case Bytecodes::_fload_0: ppload(vCTS, 0); break;
1419 case Bytecodes::_iload_1:
1420 case Bytecodes::_fload_1: ppload(vCTS, 1); break;
1421 case Bytecodes::_iload_2:
1422 case Bytecodes::_fload_2: ppload(vCTS, 2); break;
1423 case Bytecodes::_iload_3:
1424 case Bytecodes::_fload_3: ppload(vCTS, 3); break;
1425
1426 case Bytecodes::_lload_0:
1427 case Bytecodes::_dload_0: ppload(vvCTS, 0); break;
1428 case Bytecodes::_lload_1:
1429 case Bytecodes::_dload_1: ppload(vvCTS, 1); break;
1430 case Bytecodes::_lload_2:
1431 case Bytecodes::_dload_2: ppload(vvCTS, 2); break;
1432 case Bytecodes::_lload_3:
1433 case Bytecodes::_dload_3: ppload(vvCTS, 3); break;
1434
1435 case Bytecodes::_aload_0: ppload(rCTS, 0); break;
1436 case Bytecodes::_aload_1: ppload(rCTS, 1); break;
1437 case Bytecodes::_aload_2: ppload(rCTS, 2); break;
1438 case Bytecodes::_aload_3: ppload(rCTS, 3); break;
1439
1440 case Bytecodes::_iaload:
1441 case Bytecodes::_faload:
1442 case Bytecodes::_baload:
1443 case Bytecodes::_caload:
1444 case Bytecodes::_saload: pp(vrCTS, vCTS); break;
1445
1446 case Bytecodes::_laload: pp(vrCTS, vvCTS); break;
1447 case Bytecodes::_daload: pp(vrCTS, vvCTS); break;
1448
1449 case Bytecodes::_aaload: pp_new_ref(vrCTS, itr->bci()); break;
1450
1451 case Bytecodes::_istore:
1452 case Bytecodes::_fstore: ppstore(vCTS, itr->get_index()); break;
1453
1454 case Bytecodes::_lstore:
1455 case Bytecodes::_dstore: ppstore(vvCTS, itr->get_index()); break;
1456
1457 case Bytecodes::_astore: do_astore(itr->get_index()); break;
1458
1459 case Bytecodes::_istore_0:
1460 case Bytecodes::_fstore_0: ppstore(vCTS, 0); break;
1461 case Bytecodes::_istore_1:
1462 case Bytecodes::_fstore_1: ppstore(vCTS, 1); break;
1463 case Bytecodes::_istore_2:
1464 case Bytecodes::_fstore_2: ppstore(vCTS, 2); break;
1465 case Bytecodes::_istore_3:
1466 case Bytecodes::_fstore_3: ppstore(vCTS, 3); break;
1467
1468 case Bytecodes::_lstore_0:
1469 case Bytecodes::_dstore_0: ppstore(vvCTS, 0); break;
1470 case Bytecodes::_lstore_1:
1471 case Bytecodes::_dstore_1: ppstore(vvCTS, 1); break;
1472 case Bytecodes::_lstore_2:
1473 case Bytecodes::_dstore_2: ppstore(vvCTS, 2); break;
1474 case Bytecodes::_lstore_3:
1475 case Bytecodes::_dstore_3: ppstore(vvCTS, 3); break;
1476
1477 case Bytecodes::_astore_0: do_astore(0); break;
1478 case Bytecodes::_astore_1: do_astore(1); break;
1479 case Bytecodes::_astore_2: do_astore(2); break;
1480 case Bytecodes::_astore_3: do_astore(3); break;
1481
1482 case Bytecodes::_iastore:
1483 case Bytecodes::_fastore:
1484 case Bytecodes::_bastore:
1485 case Bytecodes::_castore:
1486 case Bytecodes::_sastore: ppop(vvrCTS); break;
1487 case Bytecodes::_lastore:
1488 case Bytecodes::_dastore: ppop(vvvrCTS); break;
1489 case Bytecodes::_aastore: ppop(rvrCTS); break;
1490
1491 case Bytecodes::_pop: ppop_any(1); break;
1492 case Bytecodes::_pop2: ppop_any(2); break;
1493
1494 case Bytecodes::_dup: ppdupswap(1, "11"); break;
1495 case Bytecodes::_dup_x1: ppdupswap(2, "121"); break;
1496 case Bytecodes::_dup_x2: ppdupswap(3, "1321"); break;
1497 case Bytecodes::_dup2: ppdupswap(2, "2121"); break;
1498 case Bytecodes::_dup2_x1: ppdupswap(3, "21321"); break;
1499 case Bytecodes::_dup2_x2: ppdupswap(4, "214321"); break;
1500 case Bytecodes::_swap: ppdupswap(2, "12"); break;
1501
1502 case Bytecodes::_iadd:
1503 case Bytecodes::_fadd:
1504 case Bytecodes::_isub:
1505 case Bytecodes::_fsub:
1506 case Bytecodes::_imul:
1507 case Bytecodes::_fmul:
1508 case Bytecodes::_idiv:
1509 case Bytecodes::_fdiv:
1510 case Bytecodes::_irem:
1511 case Bytecodes::_frem:
1512 case Bytecodes::_ishl:
1513 case Bytecodes::_ishr:
1514 case Bytecodes::_iushr:
1515 case Bytecodes::_iand:
1516 case Bytecodes::_ior:
1517 case Bytecodes::_ixor:
1518 case Bytecodes::_l2f:
1519 case Bytecodes::_l2i:
1520 case Bytecodes::_d2f:
1521 case Bytecodes::_d2i:
1522 case Bytecodes::_fcmpl:
1523 case Bytecodes::_fcmpg: pp(vvCTS, vCTS); break;
1524
1525 case Bytecodes::_ladd:
1526 case Bytecodes::_dadd:
1527 case Bytecodes::_lsub:
1528 case Bytecodes::_dsub:
1529 case Bytecodes::_lmul:
1530 case Bytecodes::_dmul:
1531 case Bytecodes::_ldiv:
1532 case Bytecodes::_ddiv:
1533 case Bytecodes::_lrem:
1534 case Bytecodes::_drem:
1535 case Bytecodes::_land:
1536 case Bytecodes::_lor:
1537 case Bytecodes::_lxor: pp(vvvvCTS, vvCTS); break;
1538
1539 case Bytecodes::_ineg:
1540 case Bytecodes::_fneg:
1541 case Bytecodes::_i2f:
1542 case Bytecodes::_f2i:
1543 case Bytecodes::_i2c:
1544 case Bytecodes::_i2s:
1545 case Bytecodes::_i2b: pp(vCTS, vCTS); break;
1546
1547 case Bytecodes::_lneg:
1548 case Bytecodes::_dneg:
1549 case Bytecodes::_l2d:
1550 case Bytecodes::_d2l: pp(vvCTS, vvCTS); break;
1551
1552 case Bytecodes::_lshl:
1553 case Bytecodes::_lshr:
1554 case Bytecodes::_lushr: pp(vvvCTS, vvCTS); break;
1555
1556 case Bytecodes::_i2l:
1557 case Bytecodes::_i2d:
1558 case Bytecodes::_f2l:
1559 case Bytecodes::_f2d: pp(vCTS, vvCTS); break;
1560
1561 case Bytecodes::_lcmp: pp(vvvvCTS, vCTS); break;
1562 case Bytecodes::_dcmpl:
1563 case Bytecodes::_dcmpg: pp(vvvvCTS, vCTS); break;
1564
1565 case Bytecodes::_ifeq:
1566 case Bytecodes::_ifne:
1567 case Bytecodes::_iflt:
1568 case Bytecodes::_ifge:
1569 case Bytecodes::_ifgt:
1570 case Bytecodes::_ifle:
1571 case Bytecodes::_tableswitch: ppop1(valCTS);
1572 break;
1573 case Bytecodes::_ireturn:
1574 case Bytecodes::_freturn: do_return_monitor_check();
1575 ppop1(valCTS);
1576 break;
1577 case Bytecodes::_if_icmpeq:
1578 case Bytecodes::_if_icmpne:
1579 case Bytecodes::_if_icmplt:
1580 case Bytecodes::_if_icmpge:
1581 case Bytecodes::_if_icmpgt:
1582 case Bytecodes::_if_icmple: ppop(vvCTS);
1583 break;
1584
1585 case Bytecodes::_lreturn: do_return_monitor_check();
1586 ppop(vvCTS);
1587 break;
1588
1589 case Bytecodes::_dreturn: do_return_monitor_check();
1590 ppop(vvCTS);
1591 break;
1592
1593 case Bytecodes::_if_acmpeq:
1594 case Bytecodes::_if_acmpne: ppop(rrCTS); break;
1595
1596 case Bytecodes::_jsr: do_jsr(itr->dest()); break;
1597 case Bytecodes::_jsr_w: do_jsr(itr->dest_w()); break;
1598
1599 case Bytecodes::_getstatic: do_field(true, true, itr->get_index_u2(), itr->bci(), itr->code()); break;
1600 case Bytecodes::_putstatic: do_field(false, true, itr->get_index_u2(), itr->bci(), itr->code()); break;
1601 case Bytecodes::_getfield: do_field(true, false, itr->get_index_u2(), itr->bci(), itr->code()); break;
1602 case Bytecodes::_putfield: do_field(false, false, itr->get_index_u2(), itr->bci(), itr->code()); break;
1603
1604 case Bytecodes::_invokeinterface:
1605 case Bytecodes::_invokevirtual:
1606 case Bytecodes::_invokespecial: do_method(false, itr->get_index_u2(), itr->bci(), itr->code()); break;
1607 case Bytecodes::_invokestatic: do_method(true , itr->get_index_u2(), itr->bci(), itr->code()); break;
1608 case Bytecodes::_invokedynamic: do_method(true , itr->get_index_u4(), itr->bci(), itr->code()); break;
1609 case Bytecodes::_newarray:
1610 case Bytecodes::_anewarray: pp_new_ref(vCTS, itr->bci()); break;
1611 case Bytecodes::_checkcast: do_checkcast(); break;
1612 case Bytecodes::_arraylength:
1613 case Bytecodes::_instanceof: pp(rCTS, vCTS); break;
1614 case Bytecodes::_monitorenter: do_monitorenter(itr->bci()); break;
1615 case Bytecodes::_monitorexit: do_monitorexit(itr->bci()); break;
1616
1617 case Bytecodes::_athrow: // handled by do_exception_edge() BUT ...
1618 // vlh(apple): do_exception_edge() does not get
1619 // called if method has no exception handlers
1620 if ((!_has_exceptions) && (_monitor_top > 0)) {
1621 _monitor_safe = false;
1622 }
1623 break;
1624
1625 case Bytecodes::_areturn: do_return_monitor_check();
1626 ppop1(refCTS);
1627 break;
1628
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) {
1955 in[i++] = CellTypeState::ref;
1956 }
1957 in[i] = CellTypeState::bottom;
1958 assert(i<=3, "sanity check");
1959 pp(in, out);
1960 }
1961
1962 void GenerateOopMap::do_method(int is_static, int idx, int bci, Bytecodes::Code bc) {
1963 // Dig up signature for field in constant pool
1964 ConstantPool* cp = _method->constants();
1965 Symbol* signature = cp->signature_ref_at(idx, bc);
1966
1967 // Parse method signature
1968 CellTypeState out[4];
1969 CellTypeState in[MAXARGSIZE+1]; // Includes result
1970 ComputeCallStack cse(signature);
1971
1972 // Compute return type
1973 int res_length= cse.compute_for_returntype(out);
1974
1975 // Temporary hack.
1976 if (out[0].equal(CellTypeState::ref) && out[1].equal(CellTypeState::bottom)) {
1977 out[0] = CellTypeState::make_line_ref(bci);
1978 }
1979
1980 assert(res_length<=4, "max value should be vv");
1981
1982 // Compute arguments
1983 int arg_length = cse.compute_for_parameters(is_static != 0, in);
1984 assert(arg_length<=MAXARGSIZE, "too many locals");
1985
1986 // Pop arguments
1987 for (int i = arg_length - 1; i >= 0; i--) ppop1(in[i]);// Do args in reverse order.
1988
1989 // Report results
1990 if (_report_result_for_send == true) {
1991 fill_stackmap_for_opcodes(_itr_send, vars(), stack(), _stack_top);
1992 _report_result_for_send = false;
1993 }
1994
1995 // Push return address
1996 ppush(out);
1997 }
1998
1999 // This is used to parse the signature for fields, since they are very simple...
2000 CellTypeState *GenerateOopMap::signature_to_effect(const Symbol* sig, int bci, CellTypeState *out) {
2001 // Object and array
2002 BasicType bt = Signature::basic_type(sig);
2003 if (is_reference_type(bt)) {
2004 out[0] = CellTypeState::make_line_ref(bci);
2005 out[1] = CellTypeState::bottom;
2006 return out;
2007 }
2008 if (is_double_word_type(bt)) return vvCTS; // Long and Double
2009 if (bt == T_VOID) return epsilonCTS; // Void
2010 return vCTS; // Otherwise
2011 }
2012
2013 uint64_t GenerateOopMap::_total_byte_count = 0;
2014 elapsedTimer GenerateOopMap::_total_oopmap_time;
2015
2016 // This function assumes "bcs" is at a "ret" instruction and that the vars
2017 // state is valid for that instruction. Furthermore, the ret instruction
2018 // must be the last instruction in "bb" (we store information about the
2019 // "ret" in "bb").
2020 void GenerateOopMap::ret_jump_targets_do(BytecodeStream *bcs, jmpFct_t jmpFct, int varNo, int *data) {
2021 CellTypeState ra = vars()[varNo];
2022 if (!ra.is_good_address()) {
2023 verify_error("ret returns from two jsr subroutines?");
2024 return;
2025 }
2026 int target = ra.get_info();
2027
2028 RetTableEntry* rtEnt = _rt.find_jsrs_for_target(target);
2029 int bci = bcs->bci();
2030 for (int i = 0; i < rtEnt->nof_jsrs(); i++) {
2031 int target_bci = rtEnt->jsrs(i);
2032 // Make sure a jrtRet does not set the changed bit for dead basicblock.
2033 BasicBlock* jsr_bb = get_basic_block_containing(target_bci - 1);
2034 debug_only(BasicBlock* target_bb = &jsr_bb[1];)
2035 assert(target_bb == get_basic_block_at(target_bci), "wrong calc. of successor basicblock");
2036 bool alive = jsr_bb->is_alive();
2037 if (TraceNewOopMapGeneration) {
2038 tty->print("pc = %d, ret -> %d alive: %s\n", bci, target_bci, alive ? "true" : "false");
2039 }
2040 if (alive) jmpFct(this, target_bci, data);
2041 }
2042 }
2043
2044 //
2045 // Debug method
2046 //
2047 char* GenerateOopMap::state_vec_to_string(CellTypeState* vec, int len) {
2048 #ifdef ASSERT
2049 int checklen = MAX3(_max_locals, _max_stack, _max_monitors) + 1;
2050 assert(len < checklen, "state_vec_buf overflow");
2051 #endif
2052 for (int i = 0; i < len; i++) _state_vec_buf[i] = vec[i].to_char();
2053 _state_vec_buf[len] = 0;
2054 return _state_vec_buf;
2055 }
2056
2057 void GenerateOopMap::print_time() {
2058 tty->print_cr ("Accumulated oopmap times:");
2059 tty->print_cr ("---------------------------");
2060 tty->print_cr (" Total : %3.3f sec.", GenerateOopMap::_total_oopmap_time.seconds());
2061 tty->print_cr (" (%3.0f bytecodes per sec) ",
2062 (double)GenerateOopMap::_total_byte_count / GenerateOopMap::_total_oopmap_time.seconds());
2063 }
2064
2065 //
2066 // ============ Main Entry Point ===========
2067 //
2068 GenerateOopMap::GenerateOopMap(const methodHandle& method) {
2069 // We have to initialize all variables here, that can be queried directly
2070 _method = method;
2071 _max_locals=0;
2072 _init_vars = nullptr;
2073
2074 #ifndef PRODUCT
2075 // If we are doing a detailed trace, include the regular trace information.
2076 if (TraceNewOopMapGenerationDetailed) {
2077 TraceNewOopMapGeneration = true;
2078 }
2079 #endif
2080 }
2081
2082 bool GenerateOopMap::compute_map(Thread* current) {
2083 #ifndef PRODUCT
2084 if (TimeOopMap2) {
2085 method()->print_short_name(tty);
2086 tty->print(" ");
2087 }
2088 if (TimeOopMap) {
2089 _total_byte_count += method()->code_size();
2090 }
2091 #endif
2092 TraceTime t_single("oopmap time", TimeOopMap2);
2093 TraceTime t_all(nullptr, &_total_oopmap_time, TimeOopMap);
2094
2095 // Initialize values
2096 _got_error = false;
2097 _conflict = false;
2098 _max_locals = method()->max_locals();
2099 _max_stack = method()->max_stack();
2100 _has_exceptions = (method()->has_exception_handler());
2101 _nof_refval_conflicts = 0;
2102 _init_vars = new GrowableArray<intptr_t>(5); // There are seldom more than 5 init_vars
2103 _report_result = false;
2104 _report_result_for_send = false;
2105 _new_var_map = nullptr;
2106 _ret_adr_tos = new GrowableArray<int>(5); // 5 seems like a good number;
2107 _did_rewriting = false;
2108 _did_relocation = false;
2109
2110 if (TraceNewOopMapGeneration) {
2111 tty->print("Method name: %s\n", method()->name()->as_C_string());
2112 if (Verbose) {
2113 _method->print_codes();
2114 tty->print_cr("Exception table:");
2115 ExceptionTable excps(method());
2116 for(int i = 0; i < excps.length(); i ++) {
2117 tty->print_cr("[%d - %d] -> %d",
2118 excps.start_pc(i), excps.end_pc(i), excps.handler_pc(i));
2119 }
2120 }
2121 }
2122
2123 // if no code - do nothing
2124 // compiler needs info
2125 if (method()->code_size() == 0 || _max_locals + method()->max_stack() == 0) {
2126 fill_stackmap_prolog(0);
2127 fill_stackmap_epilog();
2128 return true;
2129 }
2130 // Step 1: Compute all jump targets and their return value
2131 if (!_got_error)
2132 _rt.compute_ret_table(_method);
2133
2134 // Step 2: Find all basic blocks and count GC points
2135 if (!_got_error)
2136 mark_bbheaders_and_count_gc_points();
2137
2138 // Step 3: Calculate stack maps
2139 if (!_got_error)
2140 do_interpretation();
2141
2142 // Step 4:Return results
2143 if (!_got_error && report_results())
2144 report_result();
2145
2146 return !_got_error;
2147 }
2148
2149 // Error handling methods
2150 //
2151 // If we compute from a suitable JavaThread then we create an exception for the GenerateOopMap
2152 // calling code to retrieve (via exception()) and throw if desired (in most cases errors are ignored).
2153 // Otherwise it is considered a fatal error to hit malformed bytecode.
2154 void GenerateOopMap::error_work(const char *format, va_list ap) {
2155 _got_error = true;
2156 char msg_buffer[512];
2157 os::vsnprintf(msg_buffer, sizeof(msg_buffer), format, ap);
2158 // Append method name
2159 char msg_buffer2[512];
2160 os::snprintf(msg_buffer2, sizeof(msg_buffer2), "%s in method %s", msg_buffer, method()->name()->as_C_string());
2161 Thread* current = Thread::current();
2162 if (current->can_call_java()) {
2163 _exception = Exceptions::new_exception(JavaThread::cast(current),
2164 vmSymbols::java_lang_LinkageError(),
2165 msg_buffer2);
2166 } else {
2167 fatal("%s", msg_buffer2);
2168 }
2169 }
2170
2171 void GenerateOopMap::report_error(const char *format, ...) {
2172 va_list ap;
2173 va_start(ap, format);
2174 error_work(format, ap);
2175 }
2176
2177 void GenerateOopMap::verify_error(const char *format, ...) {
2178 // We do not distinguish between different types of errors for verification
2179 // errors. Let the verifier give a better message.
2180 report_error("Illegal class file encountered. Try running with -Xverify:all");
2181 }
2182
2183 //
2184 // Report result opcodes
2185 //
2186 void GenerateOopMap::report_result() {
2187
2188 if (TraceNewOopMapGeneration) tty->print_cr("Report result pass");
2189
2190 // We now want to report the result of the parse
2191 _report_result = true;
2192
2193 // Prolog code
2194 fill_stackmap_prolog(_gc_points);
2195
2196 // Mark everything changed, then do one interpretation pass.
2197 for (int i = 0; i<_bb_count; i++) {
2198 if (_basic_blocks[i].is_reachable()) {
2199 _basic_blocks[i].set_changed(true);
2200 interp_bb(&_basic_blocks[i]);
2201 }
2202 }
2203
2204 // Note: Since we are skipping dead-code when we are reporting results, then
2205 // the no. of encountered gc-points might be fewer than the previously number
2206 // we have counted. (dead-code is a pain - it should be removed before we get here)
2207 fill_stackmap_epilog();
2208
2209 // Report initvars
2210 fill_init_vars(_init_vars);
2211
2212 _report_result = false;
2213 }
2214
2215 void GenerateOopMap::result_for_basicblock(int bci) {
2216 if (TraceNewOopMapGeneration) tty->print_cr("Report result pass for basicblock");
2217
2218 // We now want to report the result of the parse
2219 _report_result = true;
2220
2221 // Find basicblock and report results
2222 BasicBlock* bb = get_basic_block_containing(bci);
2223 guarantee(bb != nullptr, "no basic block for bci");
2224 assert(bb->is_reachable(), "getting result from unreachable basicblock");
2225 bb->set_changed(true);
2226 interp_bb(bb);
2227 }
2228
2229 //
2230 // Conflict handling code
2231 //
2232
2233 void GenerateOopMap::record_refval_conflict(int varNo) {
2234 assert(varNo>=0 && varNo< _max_locals, "index out of range");
2235
2236 if (TraceOopMapRewrites) {
2237 tty->print("### Conflict detected (local no: %d)\n", varNo);
2238 }
2239
2240 if (!_new_var_map) {
2241 _new_var_map = NEW_RESOURCE_ARRAY(int, _max_locals);
2242 for (int k = 0; k < _max_locals; k++) _new_var_map[k] = k;
2243 }
2244
2245 if ( _new_var_map[varNo] == varNo) {
2246 // Check if max. number of locals has been reached
2247 if (_max_locals + _nof_refval_conflicts >= MAX_LOCAL_VARS) {
2248 report_error("Rewriting exceeded local variable limit");
2249 return;
2250 }
2251 _new_var_map[varNo] = _max_locals + _nof_refval_conflicts;
2252 _nof_refval_conflicts++;
2253 }
2254 }
2255
2256 void GenerateOopMap::rewrite_refval_conflicts()
2257 {
2258 // We can get here two ways: Either a rewrite conflict was detected, or
2259 // an uninitialize reference was detected. In the second case, we do not
2260 // do any rewriting, we just want to recompute the reference set with the
2261 // new information
2262
2263 int nof_conflicts = 0; // Used for debugging only
2264
2265 if ( _nof_refval_conflicts == 0 )
2266 return;
2267
2268 // Check if rewrites are allowed in this parse.
2269 if (!allow_rewrites()) {
2270 fatal("Rewriting method not allowed at this stage");
2271 }
2272
2273
2274 // Tracing flag
2275 _did_rewriting = true;
2276
2277 if (TraceOopMapRewrites) {
2278 tty->print_cr("ref/value conflict for method %s - bytecodes are getting rewritten", method()->name()->as_C_string());
2279 method()->print();
2280 method()->print_codes();
2281 }
2282
2283 assert(_new_var_map!=nullptr, "nothing to rewrite");
2284 assert(_conflict==true, "We should not be here");
2285
2286 compute_ret_adr_at_TOS();
2287 if (!_got_error) {
2288 for (int k = 0; k < _max_locals && !_got_error; k++) {
2289 if (_new_var_map[k] != k) {
2290 if (TraceOopMapRewrites) {
2291 tty->print_cr("Rewriting: %d -> %d", k, _new_var_map[k]);
2292 }
2293 rewrite_refval_conflict(k, _new_var_map[k]);
2294 if (_got_error) return;
2295 nof_conflicts++;
2296 }
2297 }
2298 }
2299
2300 assert(nof_conflicts == _nof_refval_conflicts, "sanity check");
2301
2302 // Adjust the number of locals
2303 method()->set_max_locals(_max_locals+_nof_refval_conflicts);
2304 _max_locals += _nof_refval_conflicts;
2305
2306 // That was that...
2307 _new_var_map = nullptr;
2308 _nof_refval_conflicts = 0;
2309 }
2310
2311 void GenerateOopMap::rewrite_refval_conflict(int from, int to) {
2312 bool startOver;
2313 do {
2314 // Make sure that the BytecodeStream is constructed in the loop, since
2315 // during rewriting a new method is going to be used, and the next time
2316 // around we want to use that.
2317 BytecodeStream bcs(_method);
2318 startOver = false;
2319
2320 while( !startOver && !_got_error &&
2321 // test bcs in case method changed and it became invalid
2322 bcs.next() >=0) {
2323 startOver = rewrite_refval_conflict_inst(&bcs, from, to);
2324 }
2325 } while (startOver && !_got_error);
2326 }
2327
2328 /* If the current instruction is one that uses local variable "from"
2329 in a ref way, change it to use "to". There's a subtle reason why we
2330 renumber the ref uses and not the non-ref uses: non-ref uses may be
2331 2 slots wide (double, long) which would necessitate keeping track of
2332 whether we should add one or two variables to the method. If the change
2333 affected the width of some instruction, returns "TRUE"; otherwise, returns "FALSE".
2334 Another reason for moving ref's value is for solving (addr, ref) conflicts, which
2335 both uses aload/astore methods.
2336 */
2337 bool GenerateOopMap::rewrite_refval_conflict_inst(BytecodeStream *itr, int from, int to) {
2338 Bytecodes::Code bc = itr->code();
2339 int index;
2340 int bci = itr->bci();
2341
2342 if (is_aload(itr, &index) && index == from) {
2343 if (TraceOopMapRewrites) {
2344 tty->print_cr("Rewriting aload at bci: %d", bci);
2345 }
2346 return rewrite_load_or_store(itr, Bytecodes::_aload, Bytecodes::_aload_0, to);
2347 }
2348
2349 if (is_astore(itr, &index) && index == from) {
2350 if (!stack_top_holds_ret_addr(bci)) {
2351 if (TraceOopMapRewrites) {
2352 tty->print_cr("Rewriting astore at bci: %d", bci);
2353 }
2354 return rewrite_load_or_store(itr, Bytecodes::_astore, Bytecodes::_astore_0, to);
2355 } else {
2356 if (TraceOopMapRewrites) {
2357 tty->print_cr("Suppress rewriting of astore at bci: %d", bci);
2358 }
2359 }
2360 }
2361
2362 return false;
2363 }
2364
2365 // The argument to this method is:
2366 // bc : Current bytecode
2367 // bcN : either _aload or _astore
2368 // bc0 : either _aload_0 or _astore_0
2369 bool GenerateOopMap::rewrite_load_or_store(BytecodeStream *bcs, Bytecodes::Code bcN, Bytecodes::Code bc0, unsigned int varNo) {
2370 assert(bcN == Bytecodes::_astore || bcN == Bytecodes::_aload, "wrong argument (bcN)");
2371 assert(bc0 == Bytecodes::_astore_0 || bc0 == Bytecodes::_aload_0, "wrong argument (bc0)");
2372 int ilen = Bytecodes::length_at(_method(), bcs->bcp());
2373 int newIlen;
2374
2375 if (ilen == 4) {
2376 // Original instruction was wide; keep it wide for simplicity
2377 newIlen = 4;
2378 } else if (varNo < 4)
2379 newIlen = 1;
2380 else if (varNo >= 256)
2381 newIlen = 4;
2382 else
2383 newIlen = 2;
2384
2385 // If we need to relocate in order to patch the byte, we
2386 // do the patching in a temp. buffer, that is passed to the reloc.
2387 // The patching of the bytecode stream is then done by the Relocator.
2388 // This is necessary, since relocating the instruction at a certain bci, might
2389 // also relocate that instruction, e.g., if a _goto before it gets widen to a _goto_w.
2390 // Hence, we do not know which bci to patch after relocation.
2391
2392 assert(newIlen <= 4, "sanity check");
2393 u_char inst_buffer[4]; // Max. instruction size is 4.
2394 address bcp;
2395
2396 if (newIlen != ilen) {
2397 // Relocation needed do patching in temp. buffer
2398 bcp = (address)inst_buffer;
2399 } else {
2400 bcp = _method->bcp_from(bcs->bci());
2401 }
2402
2403 // Patch either directly in Method* or in temp. buffer
2404 if (newIlen == 1) {
2405 assert(varNo < 4, "varNo too large");
2406 *bcp = (u1)(bc0 + varNo);
2407 } else if (newIlen == 2) {
2408 assert(varNo < 256, "2-byte index needed!");
2409 *(bcp + 0) = bcN;
2410 *(bcp + 1) = (u1)varNo;
2411 } else {
2412 assert(newIlen == 4, "Wrong instruction length");
2413 *(bcp + 0) = Bytecodes::_wide;
2414 *(bcp + 1) = bcN;
2415 Bytes::put_Java_u2(bcp+2, (u2)varNo);
2416 }
2417
2418 if (newIlen != ilen) {
2419 expand_current_instr(bcs->bci(), ilen, newIlen, inst_buffer);
2420 }
2421
2422
2423 return (newIlen != ilen);
2424 }
2425
2426 class RelocCallback : public RelocatorListener {
2427 private:
2428 GenerateOopMap* _gom;
2429 public:
2430 RelocCallback(GenerateOopMap* gom) { _gom = gom; };
2431
2432 // Callback method
2433 virtual void relocated(int bci, int delta, int new_code_length) {
2434 _gom->update_basic_blocks (bci, delta, new_code_length);
2435 _gom->update_ret_adr_at_TOS(bci, delta);
2436 _gom->_rt.update_ret_table (bci, delta);
2437 }
2438 };
2439
2440 // Returns true if expanding was successful. Otherwise, reports an error and
2441 // returns false.
2442 void GenerateOopMap::expand_current_instr(int bci, int ilen, int newIlen, u_char inst_buffer[]) {
2443 JavaThread* THREAD = JavaThread::current(); // For exception macros.
2444 RelocCallback rcb(this);
2445 Relocator rc(_method, &rcb);
2446 methodHandle m= rc.insert_space_at(bci, newIlen, inst_buffer, THREAD);
2447 if (m.is_null() || HAS_PENDING_EXCEPTION) {
2448 report_error("could not rewrite method - exception occurred or bytecode buffer overflow");
2449 return;
2450 }
2451
2452 // Relocator returns a new method.
2453 _did_relocation = true;
2454 _method = m;
2455 }
2456
2457
2458 bool GenerateOopMap::is_astore(BytecodeStream *itr, int *index) {
2459 Bytecodes::Code bc = itr->code();
2460 switch(bc) {
2461 case Bytecodes::_astore_0:
2462 case Bytecodes::_astore_1:
2463 case Bytecodes::_astore_2:
2464 case Bytecodes::_astore_3:
2465 *index = bc - Bytecodes::_astore_0;
2466 return true;
2467 case Bytecodes::_astore:
2468 *index = itr->get_index();
2469 return true;
2470 default:
2471 return false;
2472 }
2473 }
2474
2475 bool GenerateOopMap::is_aload(BytecodeStream *itr, int *index) {
2476 Bytecodes::Code bc = itr->code();
2477 switch(bc) {
2478 case Bytecodes::_aload_0:
2479 case Bytecodes::_aload_1:
2480 case Bytecodes::_aload_2:
2481 case Bytecodes::_aload_3:
2482 *index = bc - Bytecodes::_aload_0;
2483 return true;
2484
2485 case Bytecodes::_aload:
2486 *index = itr->get_index();
2487 return true;
2488
2489 default:
2490 return false;
2491 }
2492 }
2493
2494
2495 // Return true iff the top of the operand stack holds a return address at
2496 // the current instruction
2497 bool GenerateOopMap::stack_top_holds_ret_addr(int bci) {
2498 for(int i = 0; i < _ret_adr_tos->length(); i++) {
2499 if (_ret_adr_tos->at(i) == bci)
2500 return true;
2501 }
2502
2503 return false;
2504 }
2505
2506 void GenerateOopMap::compute_ret_adr_at_TOS() {
2507 assert(_ret_adr_tos != nullptr, "must be initialized");
2508 _ret_adr_tos->clear();
2509
2510 for (int i = 0; i < bb_count(); i++) {
2511 BasicBlock* bb = &_basic_blocks[i];
2512
2513 // Make sure to only check basicblocks that are reachable
2514 if (bb->is_reachable()) {
2515
2516 // For each Basic block we check all instructions
2517 BytecodeStream bcs(_method);
2518 bcs.set_interval(bb->_bci, next_bb_start_pc(bb));
2519
2520 restore_state(bb);
2521
2522 while (bcs.next()>=0 && !_got_error) {
2523 // TDT: should this be is_good_address() ?
2524 if (_stack_top > 0 && stack()[_stack_top-1].is_address()) {
2525 _ret_adr_tos->append(bcs.bci());
2526 if (TraceNewOopMapGeneration) {
2527 tty->print_cr("Ret_adr TOS at bci: %d", bcs.bci());
2528 }
2529 }
2530 interp1(&bcs);
2531 }
2532 }
2533 }
2534 }
2535
2536 void GenerateOopMap::update_ret_adr_at_TOS(int bci, int delta) {
2537 for(int i = 0; i < _ret_adr_tos->length(); i++) {
2538 int v = _ret_adr_tos->at(i);
2539 if (v > bci) _ret_adr_tos->at_put(i, v + delta);
2540 }
2541 }
2542
2543 // ===================================================================
2544
2545 #ifndef PRODUCT
2546 int ResolveOopMapConflicts::_nof_invocations = 0;
2547 int ResolveOopMapConflicts::_nof_rewrites = 0;
2548 int ResolveOopMapConflicts::_nof_relocations = 0;
2549 #endif
2550
2551 methodHandle ResolveOopMapConflicts::do_potential_rewrite(TRAPS) {
2552 if (!compute_map(THREAD)) {
2553 THROW_HANDLE_(exception(), methodHandle());
2554 }
2555
2556 #ifndef PRODUCT
2557 // Tracking and statistics
2558 if (PrintRewrites) {
2559 _nof_invocations++;
2560 if (did_rewriting()) {
2561 _nof_rewrites++;
2562 if (did_relocation()) _nof_relocations++;
2563 tty->print("Method was rewritten %s: ", (did_relocation()) ? "and relocated" : "");
2564 method()->print_value(); tty->cr();
2565 tty->print_cr("Cand.: %d rewrts: %d (%d%%) reloc.: %d (%d%%)",
2566 _nof_invocations,
2567 _nof_rewrites, (_nof_rewrites * 100) / _nof_invocations,
2568 _nof_relocations, (_nof_relocations * 100) / _nof_invocations);
2569 }
2570 }
2571 #endif
2572 return methodHandle(THREAD, method());
2573 }