1 /*
2 * Copyright (c) 1997, 2024, 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
146 do_parameters_on(this);
147
148 return length();
149 };
150
151 int compute_for_returntype(CellTypeState *effect) {
152 _idx = 0;
153 _effect = effect;
154 do_type(return_type(), true);
155 set(CellTypeState::bottom); // Always terminate with a bottom state, so ppush works
156
157 return length();
158 }
159 };
160
161 //=========================================================================================
162 // ComputeEntryStack
163 //
164 // Specialization of SignatureIterator - in order to set up first stack frame
165 //
166 class ComputeEntryStack : public SignatureIterator {
167 CellTypeState *_effect;
168 int _idx;
169
170 void setup();
171 void set(CellTypeState state) { _effect[_idx++] = state; }
172 int length() { return _idx; };
173
174 friend class SignatureIterator; // so do_parameters_on can call do_type
175 void do_type(BasicType type, bool for_return = false) {
176 if (for_return && type == T_VOID) {
177 set(CellTypeState::bottom);
178 } else if (is_reference_type(type)) {
179 set(CellTypeState::make_slot_ref(_idx));
180 } else {
181 assert(is_java_primitive(type), "");
182 set(CellTypeState::value);
183 if (is_double_word_type(type)) {
184 set(CellTypeState::value);
185 }
186 }
187 }
188
189 public:
190 ComputeEntryStack(Symbol* signature) : SignatureIterator(signature) {};
191
192 // Compute methods
193 int compute_for_parameters(bool is_static, CellTypeState *effect) {
194 _idx = 0;
195 _effect = effect;
196
197 if (!is_static)
198 effect[_idx++] = CellTypeState::make_slot_ref(0);
199
200 do_parameters_on(this);
201
202 return length();
203 };
204
205 int compute_for_returntype(CellTypeState *effect) {
206 _idx = 0;
207 _effect = effect;
208 do_type(return_type(), true);
209 set(CellTypeState::bottom); // Always terminate with a bottom state, so ppush works
210
211 return length();
212 }
213 };
214
215 //=====================================================================================
216 //
217 // Implementation of RetTable/RetTableEntry
218 //
219 // Contains function to itereate through all bytecodes
220 // and find all return entry points
221 //
222 int RetTable::_init_nof_entries = 10;
223 int RetTableEntry::_init_nof_jsrs = 5;
224
225 RetTableEntry::RetTableEntry(int target, RetTableEntry *next) {
226 _target_bci = target;
227 _jsrs = new GrowableArray<int>(_init_nof_jsrs);
228 _next = next;
229 }
230
231 void RetTableEntry::add_delta(int bci, int delta) {
232 if (_target_bci > bci) _target_bci += delta;
233
234 for (int k = 0; k < _jsrs->length(); k++) {
235 int jsr = _jsrs->at(k);
236 if (jsr > bci) _jsrs->at_put(k, jsr+delta);
237 }
238 }
239
240 void RetTable::compute_ret_table(const methodHandle& method) {
241 BytecodeStream i(method);
242 Bytecodes::Code bytecode;
243
244 while( (bytecode = i.next()) >= 0) {
245 switch (bytecode) {
246 case Bytecodes::_jsr:
247 add_jsr(i.next_bci(), i.dest());
248 break;
249 case Bytecodes::_jsr_w:
250 add_jsr(i.next_bci(), i.dest_w());
251 break;
252 default:
253 break;
254 }
255 }
256 }
257
258 void RetTable::add_jsr(int return_bci, int target_bci) {
259 RetTableEntry* entry = _first;
260
261 // Scan table for entry
262 for (;entry && entry->target_bci() != target_bci; entry = entry->next());
263
264 if (!entry) {
265 // Allocate new entry and put in list
266 entry = new RetTableEntry(target_bci, _first);
267 _first = entry;
268 }
269
270 // Now "entry" is set. Make sure that the entry is initialized
271 // and has room for the new jsr.
272 entry->add_jsr(return_bci);
273 }
274
275 RetTableEntry* RetTable::find_jsrs_for_target(int targBci) {
276 RetTableEntry *cur = _first;
277
278 while(cur) {
279 assert(cur->target_bci() != -1, "sanity check");
280 if (cur->target_bci() == targBci) return cur;
281 cur = cur->next();
282 }
283 ShouldNotReachHere();
284 return nullptr;
285 }
286
287 // The instruction at bci is changing size by "delta". Update the return map.
288 void RetTable::update_ret_table(int bci, int delta) {
289 RetTableEntry *cur = _first;
290 while(cur) {
291 cur->add_delta(bci, delta);
292 cur = cur->next();
293 }
294 }
295
296 //
297 // Celltype state
298 //
299
300 CellTypeState CellTypeState::bottom = CellTypeState::make_bottom();
301 CellTypeState CellTypeState::uninit = CellTypeState::make_any(uninit_value);
302 CellTypeState CellTypeState::ref = CellTypeState::make_any(ref_conflict);
303 CellTypeState CellTypeState::value = CellTypeState::make_any(val_value);
304 CellTypeState CellTypeState::refUninit = CellTypeState::make_any(ref_conflict | uninit_value);
305 CellTypeState CellTypeState::top = CellTypeState::make_top();
306 CellTypeState CellTypeState::addr = CellTypeState::make_any(addr_conflict);
307
308 // Commonly used constants
309 static CellTypeState epsilonCTS[1] = { CellTypeState::bottom };
310 static CellTypeState refCTS = CellTypeState::ref;
311 static CellTypeState valCTS = CellTypeState::value;
312 static CellTypeState vCTS[2] = { CellTypeState::value, CellTypeState::bottom };
313 static CellTypeState rCTS[2] = { CellTypeState::ref, CellTypeState::bottom };
314 static CellTypeState rrCTS[3] = { CellTypeState::ref, CellTypeState::ref, CellTypeState::bottom };
315 static CellTypeState vrCTS[3] = { CellTypeState::value, CellTypeState::ref, CellTypeState::bottom };
316 static CellTypeState vvCTS[3] = { CellTypeState::value, CellTypeState::value, CellTypeState::bottom };
317 static CellTypeState rvrCTS[4] = { CellTypeState::ref, CellTypeState::value, CellTypeState::ref, CellTypeState::bottom };
318 static CellTypeState vvrCTS[4] = { CellTypeState::value, CellTypeState::value, CellTypeState::ref, CellTypeState::bottom };
319 static CellTypeState vvvCTS[4] = { CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::bottom };
320 static CellTypeState vvvrCTS[5] = { CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::ref, CellTypeState::bottom };
321 static CellTypeState vvvvCTS[5] = { CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::bottom };
322
323 char CellTypeState::to_char() const {
324 if (can_be_reference()) {
325 if (can_be_value() || can_be_address())
326 return '#'; // Conflict that needs to be rewritten
327 else
328 return 'r';
329 } else if (can_be_value())
330 return 'v';
331 else if (can_be_address())
332 return 'p';
333 else if (can_be_uninit())
334 return ' ';
335 else
336 return '@';
337 }
338
339
340 // Print a detailed CellTypeState. Indicate all bits that are set. If
341 // the CellTypeState represents an address or a reference, print the
342 // value of the additional information.
343 void CellTypeState::print(outputStream *os) {
344 if (can_be_address()) {
345 os->print("(p");
346 } else {
347 os->print("( ");
348 }
349 if (can_be_reference()) {
350 os->print("r");
351 } else {
352 os->print(" ");
353 }
354 if (can_be_value()) {
355 os->print("v");
356 } else {
357 os->print(" ");
358 }
359 if (can_be_uninit()) {
360 os->print("u|");
361 } else {
362 os->print(" |");
363 }
364 if (is_info_top()) {
365 os->print("Top)");
366 } else if (is_info_bottom()) {
367 os->print("Bot)");
368 } else {
369 if (is_reference()) {
370 int info = get_info();
371 int data = info & ~(ref_not_lock_bit | ref_slot_bit);
372 if (info & ref_not_lock_bit) {
373 // Not a monitor lock reference.
374 if (info & ref_slot_bit) {
375 // slot
376 os->print("slot%d)", data);
377 } else {
378 // line
379 os->print("line%d)", data);
380 }
381 } else {
382 // lock
383 os->print("lock%d)", data);
384 }
385 } else {
386 os->print("%d)", get_info());
387 }
388 }
389 }
390
391 //
392 // Basicblock handling methods
393 //
394
395 void GenerateOopMap::initialize_bb() {
396 _gc_points = 0;
397 _bb_count = 0;
398 _bb_hdr_bits.reinitialize(method()->code_size());
399 }
400
401 void GenerateOopMap::bb_mark_fct(GenerateOopMap *c, int bci, int *data) {
402 assert(bci>= 0 && bci < c->method()->code_size(), "index out of bounds");
403 if (c->is_bb_header(bci))
404 return;
405
406 if (TraceNewOopMapGeneration) {
407 tty->print_cr("Basicblock#%d begins at: %d", c->_bb_count, bci);
408 }
409 c->set_bbmark_bit(bci);
410 c->_bb_count++;
411 }
412
413
414 void GenerateOopMap::mark_bbheaders_and_count_gc_points() {
415 initialize_bb();
416
417 bool fellThrough = false; // False to get first BB marked.
418
419 // First mark all exception handlers as start of a basic-block
420 ExceptionTable excps(method());
421 for(int i = 0; i < excps.length(); i ++) {
422 bb_mark_fct(this, excps.handler_pc(i), nullptr);
423 }
424
425 // Then iterate through the code
426 BytecodeStream bcs(_method);
427 Bytecodes::Code bytecode;
428
429 while( (bytecode = bcs.next()) >= 0) {
430 int bci = bcs.bci();
431
432 if (!fellThrough)
433 bb_mark_fct(this, bci, nullptr);
434
435 fellThrough = jump_targets_do(&bcs, &GenerateOopMap::bb_mark_fct, nullptr);
436
437 /* We will also mark successors of jsr's as basic block headers. */
438 switch (bytecode) {
439 case Bytecodes::_jsr:
440 case Bytecodes::_jsr_w:
441 assert(!fellThrough, "should not happen");
442 // If this is the last bytecode, there is no successor to mark
443 if (bci + Bytecodes::length_for(bytecode) < method()->code_size()) {
444 bb_mark_fct(this, bci + Bytecodes::length_for(bytecode), nullptr);
445 }
446 break;
447 default:
448 break;
449 }
450
451 if (possible_gc_point(&bcs))
452 _gc_points++;
453 }
454 }
455
456 void GenerateOopMap::set_bbmark_bit(int bci) {
457 _bb_hdr_bits.at_put(bci, true);
458 }
459
460 void GenerateOopMap::reachable_basicblock(GenerateOopMap *c, int bci, int *data) {
461 assert(bci>= 0 && bci < c->method()->code_size(), "index out of bounds");
462 BasicBlock* bb = c->get_basic_block_at(bci);
463 if (bb->is_dead()) {
464 bb->mark_as_alive();
465 *data = 1; // Mark basicblock as changed
466 }
467 }
468
469
470 void GenerateOopMap::mark_reachable_code() {
471 int change = 1; // int to get function pointers to work
472
473 // Mark entry basic block as alive and all exception handlers
474 _basic_blocks[0].mark_as_alive();
475 ExceptionTable excps(method());
476 for(int i = 0; i < excps.length(); i++) {
477 BasicBlock *bb = get_basic_block_at(excps.handler_pc(i));
478 // If block is not already alive (due to multiple exception handlers to same bb), then
479 // make it alive
480 if (bb->is_dead()) bb->mark_as_alive();
481 }
482
483 BytecodeStream bcs(_method);
484
485 // Iterate through all basic blocks until we reach a fixpoint
486 while (change) {
487 change = 0;
488
489 for (int i = 0; i < _bb_count; i++) {
490 BasicBlock *bb = &_basic_blocks[i];
491 if (bb->is_alive()) {
492 // Position bytecodestream at last bytecode in basicblock
493 bcs.set_start(bb->_end_bci);
494 bcs.next();
495 Bytecodes::Code bytecode = bcs.code();
496 int bci = bcs.bci();
497 assert(bci == bb->_end_bci, "wrong bci");
498
499 bool fell_through = jump_targets_do(&bcs, &GenerateOopMap::reachable_basicblock, &change);
500
501 // We will also mark successors of jsr's as alive.
502 switch (bytecode) {
503 case Bytecodes::_jsr:
504 case Bytecodes::_jsr_w:
505 assert(!fell_through, "should not happen");
506 // If this is the last bytecode, there is no successor to mark
507 if (bci + Bytecodes::length_for(bytecode) < method()->code_size()) {
508 reachable_basicblock(this, bci + Bytecodes::length_for(bytecode), &change);
509 }
510 break;
511 default:
512 break;
513 }
514 if (fell_through) {
515 // Mark successor as alive
516 if (bb[1].is_dead()) {
517 bb[1].mark_as_alive();
518 change = 1;
519 }
520 }
521 }
522 }
523 }
524 }
525
526 /* If the current instruction in "c" has no effect on control flow,
527 returns "true". Otherwise, calls "jmpFct" one or more times, with
528 "c", an appropriate "pcDelta", and "data" as arguments, then
529 returns "false". There is one exception: if the current
530 instruction is a "ret", returns "false" without calling "jmpFct".
531 Arrangements for tracking the control flow of a "ret" must be made
532 externally. */
533 bool GenerateOopMap::jump_targets_do(BytecodeStream *bcs, jmpFct_t jmpFct, int *data) {
534 int bci = bcs->bci();
535
536 switch (bcs->code()) {
537 case Bytecodes::_ifeq:
538 case Bytecodes::_ifne:
539 case Bytecodes::_iflt:
540 case Bytecodes::_ifge:
541 case Bytecodes::_ifgt:
542 case Bytecodes::_ifle:
543 case Bytecodes::_if_icmpeq:
544 case Bytecodes::_if_icmpne:
545 case Bytecodes::_if_icmplt:
546 case Bytecodes::_if_icmpge:
547 case Bytecodes::_if_icmpgt:
548 case Bytecodes::_if_icmple:
549 case Bytecodes::_if_acmpeq:
550 case Bytecodes::_if_acmpne:
551 case Bytecodes::_ifnull:
552 case Bytecodes::_ifnonnull:
553 (*jmpFct)(this, bcs->dest(), data);
554 // Class files verified by the old verifier can have a conditional branch
555 // as their last bytecode, provided the conditional branch is unreachable
556 // during execution. Check if this instruction is the method's last bytecode
557 // and, if so, don't call the jmpFct.
558 if (bci + 3 < method()->code_size()) {
559 (*jmpFct)(this, bci + 3, data);
560 }
561 break;
562
563 case Bytecodes::_goto:
564 (*jmpFct)(this, bcs->dest(), data);
565 break;
566 case Bytecodes::_goto_w:
567 (*jmpFct)(this, bcs->dest_w(), data);
568 break;
569 case Bytecodes::_tableswitch:
570 { Bytecode_tableswitch tableswitch(method(), bcs->bcp());
571 int len = tableswitch.length();
572
573 (*jmpFct)(this, bci + tableswitch.default_offset(), data); /* Default. jump address */
574 while (--len >= 0) {
575 (*jmpFct)(this, bci + tableswitch.dest_offset_at(len), data);
576 }
577 break;
578 }
579
580 case Bytecodes::_lookupswitch:
581 { Bytecode_lookupswitch lookupswitch(method(), bcs->bcp());
582 int npairs = lookupswitch.number_of_pairs();
583 (*jmpFct)(this, bci + lookupswitch.default_offset(), data); /* Default. */
584 while(--npairs >= 0) {
585 LookupswitchPair pair = lookupswitch.pair_at(npairs);
586 (*jmpFct)(this, bci + pair.offset(), data);
587 }
588 break;
589 }
590 case Bytecodes::_jsr:
591 assert(bcs->is_wide()==false, "sanity check");
592 (*jmpFct)(this, bcs->dest(), data);
593 break;
594 case Bytecodes::_jsr_w:
595 (*jmpFct)(this, bcs->dest_w(), data);
596 break;
597 case Bytecodes::_wide:
598 ShouldNotReachHere();
599 return true;
600 break;
601 case Bytecodes::_athrow:
602 case Bytecodes::_ireturn:
603 case Bytecodes::_lreturn:
604 case Bytecodes::_freturn:
605 case Bytecodes::_dreturn:
606 case Bytecodes::_areturn:
607 case Bytecodes::_return:
608 case Bytecodes::_ret:
609 break;
610 default:
611 return true;
612 }
613 return false;
614 }
615
616 /* Requires "pc" to be the head of a basic block; returns that basic
617 block. */
618 BasicBlock *GenerateOopMap::get_basic_block_at(int bci) const {
619 BasicBlock* bb = get_basic_block_containing(bci);
620 assert(bb->_bci == bci, "should have found BB");
621 return bb;
622 }
623
624 // Requires "pc" to be the start of an instruction; returns the basic
625 // block containing that instruction. */
626 BasicBlock *GenerateOopMap::get_basic_block_containing(int bci) const {
627 BasicBlock *bbs = _basic_blocks;
628 int lo = 0, hi = _bb_count - 1;
629
630 while (lo <= hi) {
631 int m = (lo + hi) / 2;
632 int mbci = bbs[m]._bci;
633 int nbci;
634
635 if ( m == _bb_count-1) {
636 assert( bci >= mbci && bci < method()->code_size(), "sanity check failed");
637 return bbs+m;
638 } else {
639 nbci = bbs[m+1]._bci;
640 }
641
642 if ( mbci <= bci && bci < nbci) {
643 return bbs+m;
644 } else if (mbci < bci) {
645 lo = m + 1;
646 } else {
647 assert(mbci > bci, "sanity check");
648 hi = m - 1;
649 }
650 }
651
652 fatal("should have found BB");
653 return nullptr;
654 }
655
656 void GenerateOopMap::restore_state(BasicBlock *bb)
657 {
658 memcpy(_state, bb->_state, _state_len*sizeof(CellTypeState));
659 _stack_top = bb->_stack_top;
660 _monitor_top = bb->_monitor_top;
661 }
662
663 int GenerateOopMap::next_bb_start_pc(BasicBlock *bb) {
664 intptr_t bbNum = bb - _basic_blocks + 1;
665 if (bbNum == _bb_count)
666 return method()->code_size();
667
668 return _basic_blocks[bbNum]._bci;
669 }
670
671 //
672 // CellType handling methods
673 //
674
675 // Allocate memory and throw LinkageError if failure.
676 #define ALLOC_RESOURCE_ARRAY(var, type, count) \
677 var = NEW_RESOURCE_ARRAY_RETURN_NULL(type, count); \
678 if (var == nullptr) { \
679 report_error("Cannot reserve enough memory to analyze this method"); \
680 return; \
681 }
682
683
684 void GenerateOopMap::init_state() {
685 _state_len = _max_locals + _max_stack + _max_monitors;
686 ALLOC_RESOURCE_ARRAY(_state, CellTypeState, _state_len);
687 memset(_state, 0, _state_len * sizeof(CellTypeState));
688 int count = MAX3(_max_locals, _max_stack, _max_monitors) + 1/*for null terminator char */;
689 ALLOC_RESOURCE_ARRAY(_state_vec_buf, char, count);
690 }
691
692 void GenerateOopMap::make_context_uninitialized() {
693 CellTypeState* vs = vars();
694
695 for (int i = 0; i < _max_locals; i++)
696 vs[i] = CellTypeState::uninit;
697
698 _stack_top = 0;
699 _monitor_top = 0;
700 }
701
702 int GenerateOopMap::methodsig_to_effect(Symbol* signature, bool is_static, CellTypeState* effect) {
703 ComputeEntryStack ces(signature);
704 return ces.compute_for_parameters(is_static, effect);
705 }
706
707 // Return result of merging cts1 and cts2.
708 CellTypeState CellTypeState::merge(CellTypeState cts, int slot) const {
709 CellTypeState result;
710
711 assert(!is_bottom() && !cts.is_bottom(),
712 "merge of bottom values is handled elsewhere");
713
714 result._state = _state | cts._state;
715
716 // If the top bit is set, we don't need to do any more work.
717 if (!result.is_info_top()) {
718 assert((result.can_be_address() || result.can_be_reference()),
719 "only addresses and references have non-top info");
720
721 if (!equal(cts)) {
722 // The two values being merged are different. Raise to top.
723 if (result.is_reference()) {
724 result = CellTypeState::make_slot_ref(slot);
725 } else {
726 result._state |= info_conflict;
727 }
728 }
729 }
730 assert(result.is_valid_state(), "checking that CTS merge maintains legal state");
731
732 return result;
733 }
734
735 // Merge the variable state for locals and stack from cts into bbts.
736 bool GenerateOopMap::merge_local_state_vectors(CellTypeState* cts,
737 CellTypeState* bbts) {
738 int i;
739 int len = _max_locals + _stack_top;
740 bool change = false;
741
742 for (i = len - 1; i >= 0; i--) {
743 CellTypeState v = cts[i].merge(bbts[i], i);
744 change = change || !v.equal(bbts[i]);
745 bbts[i] = v;
746 }
747
748 return change;
749 }
750
751 // Merge the monitor stack state from cts into bbts.
752 bool GenerateOopMap::merge_monitor_state_vectors(CellTypeState* cts,
753 CellTypeState* bbts) {
754 bool change = false;
755 if (_max_monitors > 0 && _monitor_top != bad_monitors) {
756 // If there are no monitors in the program, or there has been
757 // a monitor matching error before this point in the program,
758 // then we do not merge in the monitor state.
759
760 int base = _max_locals + _max_stack;
761 int len = base + _monitor_top;
762 for (int i = len - 1; i >= base; i--) {
763 CellTypeState v = cts[i].merge(bbts[i], i);
764
765 // Can we prove that, when there has been a change, it will already
766 // have been detected at this point? That would make this equal
767 // check here unnecessary.
768 change = change || !v.equal(bbts[i]);
769 bbts[i] = v;
770 }
771 }
772
773 return change;
774 }
775
776 void GenerateOopMap::copy_state(CellTypeState *dst, CellTypeState *src) {
777 int len = _max_locals + _stack_top;
778 for (int i = 0; i < len; i++) {
779 if (src[i].is_nonlock_reference()) {
780 dst[i] = CellTypeState::make_slot_ref(i);
781 } else {
782 dst[i] = src[i];
783 }
784 }
785 if (_max_monitors > 0 && _monitor_top != bad_monitors) {
786 int base = _max_locals + _max_stack;
787 len = base + _monitor_top;
788 for (int i = base; i < len; i++) {
789 dst[i] = src[i];
790 }
791 }
792 }
793
794
795 // Merge the states for the current block and the next. As long as a
796 // block is reachable the locals and stack must be merged. If the
797 // stack heights don't match then this is a verification error and
798 // it's impossible to interpret the code. Simultaneously monitor
799 // states are being check to see if they nest statically. If monitor
800 // depths match up then their states are merged. Otherwise the
801 // mismatch is simply recorded and interpretation continues since
802 // monitor matching is purely informational and doesn't say anything
803 // about the correctness of the code.
804 void GenerateOopMap::merge_state_into_bb(BasicBlock *bb) {
805 guarantee(bb != nullptr, "null basicblock");
806 assert(bb->is_alive(), "merging state into a dead basicblock");
807
808 if (_stack_top == bb->_stack_top) {
809 // always merge local state even if monitors don't match.
810 if (merge_local_state_vectors(_state, bb->_state)) {
811 bb->set_changed(true);
812 }
813 if (_monitor_top == bb->_monitor_top) {
814 // monitors still match so continue merging monitor states.
815 if (merge_monitor_state_vectors(_state, bb->_state)) {
816 bb->set_changed(true);
817 }
818 } else {
819 if (log_is_enabled(Info, monitormismatch)) {
820 report_monitor_mismatch("monitor stack height merge conflict");
821 }
822 // When the monitor stacks are not matched, we set _monitor_top to
823 // bad_monitors. This signals that, from here on, the monitor stack cannot
824 // be trusted. In particular, monitorexit bytecodes may throw
825 // exceptions. We mark this block as changed so that the change
826 // propagates properly.
827 bb->_monitor_top = bad_monitors;
828 bb->set_changed(true);
829 _monitor_safe = false;
830 }
831 } else if (!bb->is_reachable()) {
832 // First time we look at this BB
833 copy_state(bb->_state, _state);
834 bb->_stack_top = _stack_top;
835 bb->_monitor_top = _monitor_top;
836 bb->set_changed(true);
837 } else {
838 verify_error("stack height conflict: %d vs. %d", _stack_top, bb->_stack_top);
839 }
840 }
841
842 void GenerateOopMap::merge_state(GenerateOopMap *gom, int bci, int* data) {
843 gom->merge_state_into_bb(gom->get_basic_block_at(bci));
844 }
845
846 void GenerateOopMap::set_var(int localNo, CellTypeState cts) {
847 assert(cts.is_reference() || cts.is_value() || cts.is_address(),
848 "wrong celltypestate");
849 if (localNo < 0 || localNo > _max_locals) {
850 verify_error("variable write error: r%d", localNo);
851 return;
852 }
853 vars()[localNo] = cts;
854 }
855
856 CellTypeState GenerateOopMap::get_var(int localNo) {
857 assert(localNo < _max_locals + _nof_refval_conflicts, "variable read error");
858 if (localNo < 0 || localNo > _max_locals) {
859 verify_error("variable read error: r%d", localNo);
860 return valCTS; // just to pick something;
861 }
862 return vars()[localNo];
863 }
864
865 CellTypeState GenerateOopMap::pop() {
866 if ( _stack_top <= 0) {
867 verify_error("stack underflow");
868 return valCTS; // just to pick something
869 }
870 return stack()[--_stack_top];
871 }
872
873 void GenerateOopMap::push(CellTypeState cts) {
874 if ( _stack_top >= _max_stack) {
875 verify_error("stack overflow");
876 return;
877 }
878 stack()[_stack_top++] = cts;
879 }
880
881 CellTypeState GenerateOopMap::monitor_pop() {
882 assert(_monitor_top != bad_monitors, "monitor_pop called on error monitor stack");
883 if (_monitor_top == 0) {
884 // We have detected a pop of an empty monitor stack.
885 _monitor_safe = false;
886 _monitor_top = bad_monitors;
887
888 if (log_is_enabled(Info, monitormismatch)) {
889 report_monitor_mismatch("monitor stack underflow");
890 }
891 return CellTypeState::ref; // just to keep the analysis going.
892 }
893 return monitors()[--_monitor_top];
894 }
895
896 void GenerateOopMap::monitor_push(CellTypeState cts) {
897 assert(_monitor_top != bad_monitors, "monitor_push called on error monitor stack");
898 if (_monitor_top >= _max_monitors) {
899 // Some monitorenter is being executed more than once.
900 // This means that the monitor stack cannot be simulated.
901 _monitor_safe = false;
902 _monitor_top = bad_monitors;
903
904 if (log_is_enabled(Info, monitormismatch)) {
905 report_monitor_mismatch("monitor stack overflow");
906 }
907 return;
908 }
909 monitors()[_monitor_top++] = cts;
910 }
911
912 //
913 // Interpretation handling methods
914 //
915
916 void GenerateOopMap::do_interpretation()
917 {
918 // "i" is just for debugging, so we can detect cases where this loop is
919 // iterated more than once.
920 int i = 0;
921 do {
922 #ifndef PRODUCT
923 if (TraceNewOopMapGeneration) {
924 tty->print("\n\nIteration #%d of do_interpretation loop, method:\n", i);
925 method()->print_name(tty);
926 tty->print("\n\n");
927 }
928 #endif
929 _conflict = false;
930 _monitor_safe = true;
931 // init_state is now called from init_basic_blocks. The length of a
932 // state vector cannot be determined until we have made a pass through
933 // the bytecodes counting the possible monitor entries.
934 if (!_got_error) init_basic_blocks();
935 if (!_got_error) setup_method_entry_state();
936 if (!_got_error) interp_all();
937 if (!_got_error) rewrite_refval_conflicts();
938 i++;
939 } while (_conflict && !_got_error);
940 }
941
942 void GenerateOopMap::init_basic_blocks() {
943 // Note: Could consider reserving only the needed space for each BB's state
944 // (entry stack may not be of maximal height for every basic block).
945 // But cumbersome since we don't know the stack heights yet. (Nor the
946 // monitor stack heights...)
947
948 ALLOC_RESOURCE_ARRAY(_basic_blocks, BasicBlock, _bb_count);
949
950 // Make a pass through the bytecodes. Count the number of monitorenters.
951 // This can be used an upper bound on the monitor stack depth in programs
952 // which obey stack discipline with their monitor usage. Initialize the
953 // known information about basic blocks.
954 BytecodeStream j(_method);
955 Bytecodes::Code bytecode;
956
957 int bbNo = 0;
958 int monitor_count = 0;
959 int prev_bci = -1;
960 while( (bytecode = j.next()) >= 0) {
961 if (j.code() == Bytecodes::_monitorenter) {
962 monitor_count++;
963 }
964
965 int bci = j.bci();
966 if (is_bb_header(bci)) {
967 // Initialize the basicblock structure
968 BasicBlock *bb = _basic_blocks + bbNo;
969 bb->_bci = bci;
970 bb->_max_locals = _max_locals;
971 bb->_max_stack = _max_stack;
972 bb->set_changed(false);
973 bb->_stack_top = BasicBlock::_dead_basic_block; // Initialize all basicblocks are dead.
974 bb->_monitor_top = bad_monitors;
975
976 if (bbNo > 0) {
977 _basic_blocks[bbNo - 1]._end_bci = prev_bci;
978 }
979
980 bbNo++;
981 }
982 // Remember previous bci.
983 prev_bci = bci;
984 }
985 // Set
986 _basic_blocks[bbNo-1]._end_bci = prev_bci;
987
988
989 // Check that the correct number of basicblocks was found
990 if (bbNo !=_bb_count) {
991 if (bbNo < _bb_count) {
992 verify_error("jump into the middle of instruction?");
993 return;
994 } else {
995 verify_error("extra basic blocks - should not happen?");
996 return;
997 }
998 }
999
1000 _max_monitors = monitor_count;
1001
1002 // Now that we have a bound on the depth of the monitor stack, we can
1003 // initialize the CellTypeState-related information.
1004 init_state();
1005
1006 // We allocate space for all state-vectors for all basicblocks in one huge
1007 // chunk. Then in the next part of the code, we set a pointer in each
1008 // _basic_block that points to each piece.
1009
1010 // The product of bbNo and _state_len can get large if there are lots of
1011 // basic blocks and stack/locals/monitors. Need to check to make sure
1012 // we don't overflow the capacity of a pointer.
1013 if ((unsigned)bbNo > UINTPTR_MAX / sizeof(CellTypeState) / _state_len) {
1014 report_error("The amount of memory required to analyze this method "
1015 "exceeds addressable range");
1016 return;
1017 }
1018
1019 CellTypeState *basicBlockState;
1020 ALLOC_RESOURCE_ARRAY(basicBlockState, CellTypeState, bbNo * _state_len);
1021 memset(basicBlockState, 0, bbNo * _state_len * sizeof(CellTypeState));
1022
1023 // Make a pass over the basicblocks and assign their state vectors.
1024 for (int blockNum=0; blockNum < bbNo; blockNum++) {
1025 BasicBlock *bb = _basic_blocks + blockNum;
1026 bb->_state = basicBlockState + blockNum * _state_len;
1027
1028 #ifdef ASSERT
1029 if (blockNum + 1 < bbNo) {
1030 address bcp = _method->bcp_from(bb->_end_bci);
1031 int bc_len = Bytecodes::java_length_at(_method(), bcp);
1032 assert(bb->_end_bci + bc_len == bb[1]._bci, "unmatched bci info in basicblock");
1033 }
1034 #endif
1035 }
1036 #ifdef ASSERT
1037 { BasicBlock *bb = &_basic_blocks[bbNo-1];
1038 address bcp = _method->bcp_from(bb->_end_bci);
1039 int bc_len = Bytecodes::java_length_at(_method(), bcp);
1040 assert(bb->_end_bci + bc_len == _method->code_size(), "wrong end bci");
1041 }
1042 #endif
1043
1044 // Mark all alive blocks
1045 mark_reachable_code();
1046 }
1047
1048 void GenerateOopMap::setup_method_entry_state() {
1049
1050 // Initialize all locals to 'uninit' and set stack-height to 0
1051 make_context_uninitialized();
1052
1053 // Initialize CellState type of arguments
1054 methodsig_to_effect(method()->signature(), method()->is_static(), vars());
1055
1056 // If some references must be pre-assigned to null, then set that up
1057 initialize_vars();
1058
1059 // This is the start state
1060 merge_state_into_bb(&_basic_blocks[0]);
1061
1062 assert(_basic_blocks[0].changed(), "we are not getting off the ground");
1063 }
1064
1065 // The instruction at bci is changing size by "delta". Update the basic blocks.
1066 void GenerateOopMap::update_basic_blocks(int bci, int delta,
1067 int new_method_size) {
1068 assert(new_method_size >= method()->code_size() + delta,
1069 "new method size is too small");
1070
1071 _bb_hdr_bits.reinitialize(new_method_size);
1072
1073 for(int k = 0; k < _bb_count; k++) {
1074 if (_basic_blocks[k]._bci > bci) {
1075 _basic_blocks[k]._bci += delta;
1076 _basic_blocks[k]._end_bci += delta;
1077 }
1078 _bb_hdr_bits.at_put(_basic_blocks[k]._bci, true);
1079 }
1080 }
1081
1082 //
1083 // Initvars handling
1084 //
1085
1086 void GenerateOopMap::initialize_vars() {
1087 for (int k = 0; k < _init_vars->length(); k++)
1088 _state[_init_vars->at(k)] = CellTypeState::make_slot_ref(k);
1089 }
1090
1091 void GenerateOopMap::add_to_ref_init_set(int localNo) {
1092
1093 if (TraceNewOopMapGeneration)
1094 tty->print_cr("Added init vars: %d", localNo);
1095
1096 // Is it already in the set?
1097 if (_init_vars->contains(localNo) )
1098 return;
1099
1100 _init_vars->append(localNo);
1101 }
1102
1103 //
1104 // Interpreration code
1105 //
1106
1107 void GenerateOopMap::interp_all() {
1108 bool change = true;
1109
1110 while (change && !_got_error) {
1111 change = false;
1112 for (int i = 0; i < _bb_count && !_got_error; i++) {
1113 BasicBlock *bb = &_basic_blocks[i];
1114 if (bb->changed()) {
1115 if (_got_error) return;
1116 change = true;
1117 bb->set_changed(false);
1118 interp_bb(bb);
1119 }
1120 }
1121 }
1122 }
1123
1124 void GenerateOopMap::interp_bb(BasicBlock *bb) {
1125
1126 // We do not want to do anything in case the basic-block has not been initialized. This
1127 // will happen in the case where there is dead-code hang around in a method.
1128 assert(bb->is_reachable(), "should be reachable or deadcode exist");
1129 restore_state(bb);
1130
1131 BytecodeStream itr(_method);
1132
1133 // Set iterator interval to be the current basicblock
1134 int lim_bci = next_bb_start_pc(bb);
1135 itr.set_interval(bb->_bci, lim_bci);
1136 assert(lim_bci != bb->_bci, "must be at least one instruction in a basicblock");
1137 itr.next(); // read first instruction
1138
1139 // Iterates through all bytecodes except the last in a basic block.
1140 // We handle the last one special, since there is controlflow change.
1141 while(itr.next_bci() < lim_bci && !_got_error) {
1142 if (_has_exceptions || _monitor_top != 0) {
1143 // We do not need to interpret the results of exceptional
1144 // continuation from this instruction when the method has no
1145 // exception handlers and the monitor stack is currently
1146 // empty.
1147 do_exception_edge(&itr);
1148 }
1149 interp1(&itr);
1150 itr.next();
1151 }
1152
1153 // Handle last instruction.
1154 if (!_got_error) {
1155 assert(itr.next_bci() == lim_bci, "must point to end");
1156 if (_has_exceptions || _monitor_top != 0) {
1157 do_exception_edge(&itr);
1158 }
1159 interp1(&itr);
1160
1161 bool fall_through = jump_targets_do(&itr, GenerateOopMap::merge_state, nullptr);
1162 if (_got_error) return;
1163
1164 if (itr.code() == Bytecodes::_ret) {
1165 assert(!fall_through, "cannot be set if ret instruction");
1166 // Automatically handles 'wide' ret indices
1167 ret_jump_targets_do(&itr, GenerateOopMap::merge_state, itr.get_index(), nullptr);
1168 } else if (fall_through) {
1169 // Hit end of BB, but the instr. was a fall-through instruction,
1170 // so perform transition as if the BB ended in a "jump".
1171 if (lim_bci != bb[1]._bci) {
1172 verify_error("bytecodes fell through last instruction");
1173 return;
1174 }
1175 merge_state_into_bb(bb + 1);
1176 }
1177 }
1178 }
1179
1180 void GenerateOopMap::do_exception_edge(BytecodeStream* itr) {
1181 // Only check exception edge, if bytecode can trap
1182 if (!Bytecodes::can_trap(itr->code())) return;
1183 switch (itr->code()) {
1184 case Bytecodes::_aload_0:
1185 // These bytecodes can trap for rewriting. We need to assume that
1186 // they do not throw exceptions to make the monitor analysis work.
1187 return;
1188
1189 case Bytecodes::_ireturn:
1190 case Bytecodes::_lreturn:
1191 case Bytecodes::_freturn:
1192 case Bytecodes::_dreturn:
1193 case Bytecodes::_areturn:
1194 case Bytecodes::_return:
1195 // If the monitor stack height is not zero when we leave the method,
1196 // then we are either exiting with a non-empty stack or we have
1197 // found monitor trouble earlier in our analysis. In either case,
1198 // assume an exception could be taken here.
1199 if (_monitor_top == 0) {
1200 return;
1201 }
1202 break;
1203
1204 case Bytecodes::_monitorexit:
1205 // If the monitor stack height is bad_monitors, then we have detected a
1206 // monitor matching problem earlier in the analysis. If the
1207 // monitor stack height is 0, we are about to pop a monitor
1208 // off of an empty stack. In either case, the bytecode
1209 // could throw an exception.
1210 if (_monitor_top != bad_monitors && _monitor_top != 0) {
1211 return;
1212 }
1213 break;
1214
1215 default:
1216 break;
1217 }
1218
1219 if (_has_exceptions) {
1220 int bci = itr->bci();
1221 ExceptionTable exct(method());
1222 for(int i = 0; i< exct.length(); i++) {
1223 int start_pc = exct.start_pc(i);
1224 int end_pc = exct.end_pc(i);
1225 int handler_pc = exct.handler_pc(i);
1226 int catch_type = exct.catch_type_index(i);
1227
1228 if (start_pc <= bci && bci < end_pc) {
1229 BasicBlock *excBB = get_basic_block_at(handler_pc);
1230 guarantee(excBB != nullptr, "no basic block for exception");
1231 CellTypeState *excStk = excBB->stack();
1232 CellTypeState *cOpStck = stack();
1233 CellTypeState cOpStck_0 = cOpStck[0];
1234 int cOpStackTop = _stack_top;
1235
1236 // Exception stacks are always the same.
1237 assert(method()->max_stack() > 0, "sanity check");
1238
1239 // We remembered the size and first element of "cOpStck"
1240 // above; now we temporarily set them to the appropriate
1241 // values for an exception handler. */
1242 cOpStck[0] = CellTypeState::make_slot_ref(_max_locals);
1243 _stack_top = 1;
1244
1245 merge_state_into_bb(excBB);
1246
1247 // Now undo the temporary change.
1248 cOpStck[0] = cOpStck_0;
1249 _stack_top = cOpStackTop;
1250
1251 // If this is a "catch all" handler, then we do not need to
1252 // consider any additional handlers.
1253 if (catch_type == 0) {
1254 return;
1255 }
1256 }
1257 }
1258 }
1259
1260 // It is possible that none of the exception handlers would have caught
1261 // the exception. In this case, we will exit the method. We must
1262 // ensure that the monitor stack is empty in this case.
1263 if (_monitor_top == 0) {
1264 return;
1265 }
1266
1267 // We pessimistically assume that this exception can escape the
1268 // method. (It is possible that it will always be caught, but
1269 // we don't care to analyse the types of the catch clauses.)
1270
1271 // We don't set _monitor_top to bad_monitors because there are no successors
1272 // to this exceptional exit.
1273
1274 if (log_is_enabled(Info, monitormismatch) && _monitor_safe) {
1275 // We check _monitor_safe so that we only report the first mismatched
1276 // exceptional exit.
1277 report_monitor_mismatch("non-empty monitor stack at exceptional exit");
1278 }
1279 _monitor_safe = false;
1280
1281 }
1282
1283 void GenerateOopMap::report_monitor_mismatch(const char *msg) {
1284 ResourceMark rm;
1285 LogStream ls(Log(monitormismatch)::info());
1286 ls.print("Monitor mismatch in method ");
1287 method()->print_short_name(&ls);
1288 ls.print_cr(": %s", msg);
1289 }
1290
1291 void GenerateOopMap::print_states(outputStream *os,
1292 CellTypeState* vec, int num) {
1293 for (int i = 0; i < num; i++) {
1294 vec[i].print(tty);
1295 }
1296 }
1297
1298 // Print the state values at the current bytecode.
1299 void GenerateOopMap::print_current_state(outputStream *os,
1300 BytecodeStream *currentBC,
1301 bool detailed) {
1302 if (detailed) {
1303 os->print(" %4d vars = ", currentBC->bci());
1304 print_states(os, vars(), _max_locals);
1305 os->print(" %s", Bytecodes::name(currentBC->code()));
1306 } else {
1307 os->print(" %4d vars = '%s' ", currentBC->bci(), state_vec_to_string(vars(), _max_locals));
1308 os->print(" stack = '%s' ", state_vec_to_string(stack(), _stack_top));
1309 if (_monitor_top != bad_monitors) {
1310 os->print(" monitors = '%s' \t%s", state_vec_to_string(monitors(), _monitor_top), Bytecodes::name(currentBC->code()));
1311 } else {
1312 os->print(" [bad monitor stack]");
1313 }
1314 }
1315
1316 switch(currentBC->code()) {
1317 case Bytecodes::_invokevirtual:
1318 case Bytecodes::_invokespecial:
1319 case Bytecodes::_invokestatic:
1320 case Bytecodes::_invokedynamic:
1321 case Bytecodes::_invokeinterface: {
1322 int idx = currentBC->has_index_u4() ? currentBC->get_index_u4() : currentBC->get_index_u2();
1323 ConstantPool* cp = method()->constants();
1324 int nameAndTypeIdx = cp->name_and_type_ref_index_at(idx, currentBC->code());
1325 int signatureIdx = cp->signature_ref_index_at(nameAndTypeIdx);
1326 Symbol* signature = cp->symbol_at(signatureIdx);
1327 os->print("%s", signature->as_C_string());
1328 }
1329 default:
1330 break;
1331 }
1332
1333 if (detailed) {
1334 os->cr();
1335 os->print(" stack = ");
1336 print_states(os, stack(), _stack_top);
1337 os->cr();
1338 if (_monitor_top != bad_monitors) {
1339 os->print(" monitors = ");
1340 print_states(os, monitors(), _monitor_top);
1341 } else {
1342 os->print(" [bad monitor stack]");
1343 }
1344 }
1345
1346 os->cr();
1347 }
1348
1349 // Sets the current state to be the state after executing the
1350 // current instruction, starting in the current state.
1351 void GenerateOopMap::interp1(BytecodeStream *itr) {
1352 if (TraceNewOopMapGeneration) {
1353 print_current_state(tty, itr, TraceNewOopMapGenerationDetailed);
1354 }
1355
1356 // Should we report the results? Result is reported *before* the instruction at the current bci is executed.
1357 // However, not for calls. For calls we do not want to include the arguments, so we postpone the reporting until
1358 // they have been popped (in method ppl).
1359 if (_report_result == true) {
1360 switch(itr->code()) {
1361 case Bytecodes::_invokevirtual:
1362 case Bytecodes::_invokespecial:
1363 case Bytecodes::_invokestatic:
1364 case Bytecodes::_invokedynamic:
1365 case Bytecodes::_invokeinterface:
1366 _itr_send = itr;
1367 _report_result_for_send = true;
1368 break;
1369 default:
1370 fill_stackmap_for_opcodes(itr, vars(), stack(), _stack_top);
1371 break;
1372 }
1373 }
1374
1375 // abstract interpretation of current opcode
1376 switch(itr->code()) {
1377 case Bytecodes::_nop: break;
1378 case Bytecodes::_goto: break;
1379 case Bytecodes::_goto_w: break;
1380 case Bytecodes::_iinc: break;
1381 case Bytecodes::_return: do_return_monitor_check();
1382 break;
1383
1384 case Bytecodes::_aconst_null:
1385 case Bytecodes::_new: ppush1(CellTypeState::make_line_ref(itr->bci()));
1386 break;
1387
1388 case Bytecodes::_iconst_m1:
1389 case Bytecodes::_iconst_0:
1390 case Bytecodes::_iconst_1:
1391 case Bytecodes::_iconst_2:
1392 case Bytecodes::_iconst_3:
1393 case Bytecodes::_iconst_4:
1394 case Bytecodes::_iconst_5:
1395 case Bytecodes::_fconst_0:
1396 case Bytecodes::_fconst_1:
1397 case Bytecodes::_fconst_2:
1398 case Bytecodes::_bipush:
1399 case Bytecodes::_sipush: ppush1(valCTS); break;
1400
1401 case Bytecodes::_lconst_0:
1402 case Bytecodes::_lconst_1:
1403 case Bytecodes::_dconst_0:
1404 case Bytecodes::_dconst_1: ppush(vvCTS); break;
1405
1406 case Bytecodes::_ldc2_w: ppush(vvCTS); break;
1407
1408 case Bytecodes::_ldc: // fall through:
1409 case Bytecodes::_ldc_w: do_ldc(itr->bci()); break;
1410
1411 case Bytecodes::_iload:
1412 case Bytecodes::_fload: ppload(vCTS, itr->get_index()); break;
1413
1414 case Bytecodes::_lload:
1415 case Bytecodes::_dload: ppload(vvCTS,itr->get_index()); break;
1416
1417 case Bytecodes::_aload: ppload(rCTS, itr->get_index()); break;
1418
1419 case Bytecodes::_iload_0:
1420 case Bytecodes::_fload_0: ppload(vCTS, 0); break;
1421 case Bytecodes::_iload_1:
1422 case Bytecodes::_fload_1: ppload(vCTS, 1); break;
1423 case Bytecodes::_iload_2:
1424 case Bytecodes::_fload_2: ppload(vCTS, 2); break;
1425 case Bytecodes::_iload_3:
1426 case Bytecodes::_fload_3: ppload(vCTS, 3); break;
1427
1428 case Bytecodes::_lload_0:
1429 case Bytecodes::_dload_0: ppload(vvCTS, 0); break;
1430 case Bytecodes::_lload_1:
1431 case Bytecodes::_dload_1: ppload(vvCTS, 1); break;
1432 case Bytecodes::_lload_2:
1433 case Bytecodes::_dload_2: ppload(vvCTS, 2); break;
1434 case Bytecodes::_lload_3:
1435 case Bytecodes::_dload_3: ppload(vvCTS, 3); break;
1436
1437 case Bytecodes::_aload_0: ppload(rCTS, 0); break;
1438 case Bytecodes::_aload_1: ppload(rCTS, 1); break;
1439 case Bytecodes::_aload_2: ppload(rCTS, 2); break;
1440 case Bytecodes::_aload_3: ppload(rCTS, 3); break;
1441
1442 case Bytecodes::_iaload:
1443 case Bytecodes::_faload:
1444 case Bytecodes::_baload:
1445 case Bytecodes::_caload:
1446 case Bytecodes::_saload: pp(vrCTS, vCTS); break;
1447
1448 case Bytecodes::_laload: pp(vrCTS, vvCTS); break;
1449 case Bytecodes::_daload: pp(vrCTS, vvCTS); break;
1450
1451 case Bytecodes::_aaload: pp_new_ref(vrCTS, itr->bci()); break;
1452
1453 case Bytecodes::_istore:
1454 case Bytecodes::_fstore: ppstore(vCTS, itr->get_index()); break;
1455
1456 case Bytecodes::_lstore:
1457 case Bytecodes::_dstore: ppstore(vvCTS, itr->get_index()); break;
1458
1459 case Bytecodes::_astore: do_astore(itr->get_index()); break;
1460
1461 case Bytecodes::_istore_0:
1462 case Bytecodes::_fstore_0: ppstore(vCTS, 0); break;
1463 case Bytecodes::_istore_1:
1464 case Bytecodes::_fstore_1: ppstore(vCTS, 1); break;
1465 case Bytecodes::_istore_2:
1466 case Bytecodes::_fstore_2: ppstore(vCTS, 2); break;
1467 case Bytecodes::_istore_3:
1468 case Bytecodes::_fstore_3: ppstore(vCTS, 3); break;
1469
1470 case Bytecodes::_lstore_0:
1471 case Bytecodes::_dstore_0: ppstore(vvCTS, 0); break;
1472 case Bytecodes::_lstore_1:
1473 case Bytecodes::_dstore_1: ppstore(vvCTS, 1); break;
1474 case Bytecodes::_lstore_2:
1475 case Bytecodes::_dstore_2: ppstore(vvCTS, 2); break;
1476 case Bytecodes::_lstore_3:
1477 case Bytecodes::_dstore_3: ppstore(vvCTS, 3); break;
1478
1479 case Bytecodes::_astore_0: do_astore(0); break;
1480 case Bytecodes::_astore_1: do_astore(1); break;
1481 case Bytecodes::_astore_2: do_astore(2); break;
1482 case Bytecodes::_astore_3: do_astore(3); break;
1483
1484 case Bytecodes::_iastore:
1485 case Bytecodes::_fastore:
1486 case Bytecodes::_bastore:
1487 case Bytecodes::_castore:
1488 case Bytecodes::_sastore: ppop(vvrCTS); break;
1489 case Bytecodes::_lastore:
1490 case Bytecodes::_dastore: ppop(vvvrCTS); break;
1491 case Bytecodes::_aastore: ppop(rvrCTS); break;
1492
1493 case Bytecodes::_pop: ppop_any(1); break;
1494 case Bytecodes::_pop2: ppop_any(2); break;
1495
1496 case Bytecodes::_dup: ppdupswap(1, "11"); break;
1497 case Bytecodes::_dup_x1: ppdupswap(2, "121"); break;
1498 case Bytecodes::_dup_x2: ppdupswap(3, "1321"); break;
1499 case Bytecodes::_dup2: ppdupswap(2, "2121"); break;
1500 case Bytecodes::_dup2_x1: ppdupswap(3, "21321"); break;
1501 case Bytecodes::_dup2_x2: ppdupswap(4, "214321"); break;
1502 case Bytecodes::_swap: ppdupswap(2, "12"); break;
1503
1504 case Bytecodes::_iadd:
1505 case Bytecodes::_fadd:
1506 case Bytecodes::_isub:
1507 case Bytecodes::_fsub:
1508 case Bytecodes::_imul:
1509 case Bytecodes::_fmul:
1510 case Bytecodes::_idiv:
1511 case Bytecodes::_fdiv:
1512 case Bytecodes::_irem:
1513 case Bytecodes::_frem:
1514 case Bytecodes::_ishl:
1515 case Bytecodes::_ishr:
1516 case Bytecodes::_iushr:
1517 case Bytecodes::_iand:
1518 case Bytecodes::_ior:
1519 case Bytecodes::_ixor:
1520 case Bytecodes::_l2f:
1521 case Bytecodes::_l2i:
1522 case Bytecodes::_d2f:
1523 case Bytecodes::_d2i:
1524 case Bytecodes::_fcmpl:
1525 case Bytecodes::_fcmpg: pp(vvCTS, vCTS); break;
1526
1527 case Bytecodes::_ladd:
1528 case Bytecodes::_dadd:
1529 case Bytecodes::_lsub:
1530 case Bytecodes::_dsub:
1531 case Bytecodes::_lmul:
1532 case Bytecodes::_dmul:
1533 case Bytecodes::_ldiv:
1534 case Bytecodes::_ddiv:
1535 case Bytecodes::_lrem:
1536 case Bytecodes::_drem:
1537 case Bytecodes::_land:
1538 case Bytecodes::_lor:
1539 case Bytecodes::_lxor: pp(vvvvCTS, vvCTS); break;
1540
1541 case Bytecodes::_ineg:
1542 case Bytecodes::_fneg:
1543 case Bytecodes::_i2f:
1544 case Bytecodes::_f2i:
1545 case Bytecodes::_i2c:
1546 case Bytecodes::_i2s:
1547 case Bytecodes::_i2b: pp(vCTS, vCTS); break;
1548
1549 case Bytecodes::_lneg:
1550 case Bytecodes::_dneg:
1551 case Bytecodes::_l2d:
1552 case Bytecodes::_d2l: pp(vvCTS, vvCTS); break;
1553
1554 case Bytecodes::_lshl:
1555 case Bytecodes::_lshr:
1556 case Bytecodes::_lushr: pp(vvvCTS, vvCTS); break;
1557
1558 case Bytecodes::_i2l:
1559 case Bytecodes::_i2d:
1560 case Bytecodes::_f2l:
1561 case Bytecodes::_f2d: pp(vCTS, vvCTS); break;
1562
1563 case Bytecodes::_lcmp: pp(vvvvCTS, vCTS); break;
1564 case Bytecodes::_dcmpl:
1565 case Bytecodes::_dcmpg: pp(vvvvCTS, vCTS); break;
1566
1567 case Bytecodes::_ifeq:
1568 case Bytecodes::_ifne:
1569 case Bytecodes::_iflt:
1570 case Bytecodes::_ifge:
1571 case Bytecodes::_ifgt:
1572 case Bytecodes::_ifle:
1573 case Bytecodes::_tableswitch: ppop1(valCTS);
1574 break;
1575 case Bytecodes::_ireturn:
1576 case Bytecodes::_freturn: do_return_monitor_check();
1577 ppop1(valCTS);
1578 break;
1579 case Bytecodes::_if_icmpeq:
1580 case Bytecodes::_if_icmpne:
1581 case Bytecodes::_if_icmplt:
1582 case Bytecodes::_if_icmpge:
1583 case Bytecodes::_if_icmpgt:
1584 case Bytecodes::_if_icmple: ppop(vvCTS);
1585 break;
1586
1587 case Bytecodes::_lreturn: do_return_monitor_check();
1588 ppop(vvCTS);
1589 break;
1590
1591 case Bytecodes::_dreturn: do_return_monitor_check();
1592 ppop(vvCTS);
1593 break;
1594
1595 case Bytecodes::_if_acmpeq:
1596 case Bytecodes::_if_acmpne: ppop(rrCTS); break;
1597
1598 case Bytecodes::_jsr: do_jsr(itr->dest()); break;
1599 case Bytecodes::_jsr_w: do_jsr(itr->dest_w()); break;
1600
1601 case Bytecodes::_getstatic: do_field(true, true, itr->get_index_u2(), itr->bci(), itr->code()); break;
1602 case Bytecodes::_putstatic: do_field(false, true, itr->get_index_u2(), itr->bci(), itr->code()); break;
1603 case Bytecodes::_getfield: do_field(true, false, itr->get_index_u2(), itr->bci(), itr->code()); break;
1604 case Bytecodes::_putfield: do_field(false, false, itr->get_index_u2(), itr->bci(), itr->code()); break;
1605
1606 case Bytecodes::_invokeinterface:
1607 case Bytecodes::_invokevirtual:
1608 case Bytecodes::_invokespecial: do_method(false, itr->get_index_u2(), itr->bci(), itr->code()); break;
1609 case Bytecodes::_invokestatic: do_method(true , itr->get_index_u2(), itr->bci(), itr->code()); break;
1610 case Bytecodes::_invokedynamic: do_method(true , itr->get_index_u4(), itr->bci(), itr->code()); break;
1611 case Bytecodes::_newarray:
1612 case Bytecodes::_anewarray: pp_new_ref(vCTS, itr->bci()); break;
1613 case Bytecodes::_checkcast: do_checkcast(); break;
1614 case Bytecodes::_arraylength:
1615 case Bytecodes::_instanceof: pp(rCTS, vCTS); break;
1616 case Bytecodes::_monitorenter: do_monitorenter(itr->bci()); break;
1617 case Bytecodes::_monitorexit: do_monitorexit(itr->bci()); break;
1618
1619 case Bytecodes::_athrow: // handled by do_exception_edge() BUT ...
1620 // vlh(apple): do_exception_edge() does not get
1621 // called if method has no exception handlers
1622 if ((!_has_exceptions) && (_monitor_top > 0)) {
1623 _monitor_safe = false;
1624 }
1625 break;
1626
1627 case Bytecodes::_areturn: do_return_monitor_check();
1628 ppop1(refCTS);
1629 break;
1630
1631 case Bytecodes::_ifnull:
1632 case Bytecodes::_ifnonnull: ppop1(refCTS); break;
1633 case Bytecodes::_multianewarray: do_multianewarray(*(itr->bcp()+3), itr->bci()); break;
1634
1635 case Bytecodes::_wide: fatal("Iterator should skip this bytecode"); break;
1636 case Bytecodes::_ret: break;
1637
1638 // Java opcodes
1639 case Bytecodes::_lookupswitch: ppop1(valCTS); break;
1640
1641 default:
1642 tty->print("unexpected opcode: %d\n", itr->code());
1643 ShouldNotReachHere();
1644 break;
1645 }
1646 }
1647
1648 void GenerateOopMap::check_type(CellTypeState expected, CellTypeState actual) {
1649 if (!expected.equal_kind(actual)) {
1650 verify_error("wrong type on stack (found: %c expected: %c)", actual.to_char(), expected.to_char());
1651 }
1652 }
1653
1654 void GenerateOopMap::ppstore(CellTypeState *in, int loc_no) {
1655 while(!(*in).is_bottom()) {
1656 CellTypeState expected =*in++;
1657 CellTypeState actual = pop();
1658 check_type(expected, actual);
1659 assert(loc_no >= 0, "sanity check");
1660 set_var(loc_no++, actual);
1661 }
1662 }
1663
1664 void GenerateOopMap::ppload(CellTypeState *out, int loc_no) {
1665 while(!(*out).is_bottom()) {
1666 CellTypeState out1 = *out++;
1667 CellTypeState vcts = get_var(loc_no);
1668 assert(out1.can_be_reference() || out1.can_be_value(),
1669 "can only load refs. and values.");
1670 if (out1.is_reference()) {
1671 assert(loc_no>=0, "sanity check");
1672 if (!vcts.is_reference()) {
1673 // We were asked to push a reference, but the type of the
1674 // variable can be something else
1675 _conflict = true;
1676 if (vcts.can_be_uninit()) {
1677 // It is a ref-uninit conflict (at least). If there are other
1678 // problems, we'll get them in the next round
1679 add_to_ref_init_set(loc_no);
1680 vcts = out1;
1681 } else {
1682 // It wasn't a ref-uninit conflict. So must be a
1683 // ref-val or ref-pc conflict. Split the variable.
1684 record_refval_conflict(loc_no);
1685 vcts = out1;
1686 }
1687 push(out1); // recover...
1688 } else {
1689 push(vcts); // preserve reference.
1690 }
1691 // Otherwise it is a conflict, but one that verification would
1692 // have caught if illegal. In particular, it can't be a topCTS
1693 // resulting from mergeing two difference pcCTS's since the verifier
1694 // would have rejected any use of such a merge.
1695 } else {
1696 push(out1); // handle val/init conflict
1697 }
1698 loc_no++;
1699 }
1700 }
1701
1702 void GenerateOopMap::ppdupswap(int poplen, const char *out) {
1703 CellTypeState actual[5];
1704 assert(poplen < 5, "this must be less than length of actual vector");
1705
1706 // Pop all arguments.
1707 for (int i = 0; i < poplen; i++) {
1708 actual[i] = pop();
1709 }
1710 // Field _state is uninitialized when calling push.
1711 for (int i = poplen; i < 5; i++) {
1712 actual[i] = CellTypeState::uninit;
1713 }
1714
1715 // put them back
1716 char push_ch = *out++;
1717 while (push_ch != '\0') {
1718 int idx = push_ch - '1';
1719 assert(idx >= 0 && idx < poplen, "wrong arguments");
1720 push(actual[idx]);
1721 push_ch = *out++;
1722 }
1723 }
1724
1725 void GenerateOopMap::ppop1(CellTypeState out) {
1726 CellTypeState actual = pop();
1727 check_type(out, actual);
1728 }
1729
1730 void GenerateOopMap::ppop(CellTypeState *out) {
1731 while (!(*out).is_bottom()) {
1732 ppop1(*out++);
1733 }
1734 }
1735
1736 void GenerateOopMap::ppush1(CellTypeState in) {
1737 assert(in.is_reference() || in.is_value(), "sanity check");
1738 push(in);
1739 }
1740
1741 void GenerateOopMap::ppush(CellTypeState *in) {
1742 while (!(*in).is_bottom()) {
1743 ppush1(*in++);
1744 }
1745 }
1746
1747 void GenerateOopMap::pp(CellTypeState *in, CellTypeState *out) {
1748 ppop(in);
1749 ppush(out);
1750 }
1751
1752 void GenerateOopMap::pp_new_ref(CellTypeState *in, int bci) {
1753 ppop(in);
1754 ppush1(CellTypeState::make_line_ref(bci));
1755 }
1756
1757 void GenerateOopMap::ppop_any(int poplen) {
1758 if (_stack_top >= poplen) {
1759 _stack_top -= poplen;
1760 } else {
1761 verify_error("stack underflow");
1762 }
1763 }
1764
1765 // Replace all occurrences of the state 'match' with the state 'replace'
1766 // in our current state vector.
1767 void GenerateOopMap::replace_all_CTS_matches(CellTypeState match,
1768 CellTypeState replace) {
1769 int i;
1770 int len = _max_locals + _stack_top;
1771 bool change = false;
1772
1773 for (i = len - 1; i >= 0; i--) {
1774 if (match.equal(_state[i])) {
1775 _state[i] = replace;
1776 }
1777 }
1778
1779 if (_monitor_top > 0) {
1780 int base = _max_locals + _max_stack;
1781 len = base + _monitor_top;
1782 for (i = len - 1; i >= base; i--) {
1783 if (match.equal(_state[i])) {
1784 _state[i] = replace;
1785 }
1786 }
1787 }
1788 }
1789
1790 void GenerateOopMap::do_checkcast() {
1791 CellTypeState actual = pop();
1792 check_type(refCTS, actual);
1793 push(actual);
1794 }
1795
1796 void GenerateOopMap::do_monitorenter(int bci) {
1797 CellTypeState actual = pop();
1798 if (_monitor_top == bad_monitors) {
1799 return;
1800 }
1801
1802 // Bail out when we get repeated locks on an identical monitor. This case
1803 // isn't too hard to handle and can be made to work if supporting nested
1804 // redundant synchronized statements becomes a priority.
1805 //
1806 // See also "Note" in do_monitorexit(), below.
1807 if (actual.is_lock_reference()) {
1808 _monitor_top = bad_monitors;
1809 _monitor_safe = false;
1810
1811 if (log_is_enabled(Info, monitormismatch)) {
1812 report_monitor_mismatch("nested redundant lock -- bailout...");
1813 }
1814 return;
1815 }
1816
1817 CellTypeState lock = CellTypeState::make_lock_ref(bci);
1818 check_type(refCTS, actual);
1819 if (!actual.is_info_top()) {
1820 replace_all_CTS_matches(actual, lock);
1821 monitor_push(lock);
1822 }
1823 }
1824
1825 void GenerateOopMap::do_monitorexit(int bci) {
1826 CellTypeState actual = pop();
1827 if (_monitor_top == bad_monitors) {
1828 return;
1829 }
1830 check_type(refCTS, actual);
1831 CellTypeState expected = monitor_pop();
1832 if (!actual.is_lock_reference() || !expected.equal(actual)) {
1833 // The monitor we are exiting is not verifiably the one
1834 // on the top of our monitor stack. This causes a monitor
1835 // mismatch.
1836 _monitor_top = bad_monitors;
1837 _monitor_safe = false;
1838
1839 // We need to mark this basic block as changed so that
1840 // this monitorexit will be visited again. We need to
1841 // do this to ensure that we have accounted for the
1842 // possibility that this bytecode will throw an
1843 // exception.
1844 BasicBlock* bb = get_basic_block_containing(bci);
1845 guarantee(bb != nullptr, "no basic block for bci");
1846 bb->set_changed(true);
1847 bb->_monitor_top = bad_monitors;
1848
1849 if (log_is_enabled(Info, monitormismatch)) {
1850 report_monitor_mismatch("improper monitor pair");
1851 }
1852 } else {
1853 // This code is a fix for the case where we have repeated
1854 // locking of the same object in straightline code. We clear
1855 // out the lock when it is popped from the monitor stack
1856 // and replace it with an unobtrusive reference value that can
1857 // be locked again.
1858 //
1859 // Note: when generateOopMap is fixed to properly handle repeated,
1860 // nested, redundant locks on the same object, then this
1861 // fix will need to be removed at that time.
1862 replace_all_CTS_matches(actual, CellTypeState::make_line_ref(bci));
1863 }
1864 }
1865
1866 void GenerateOopMap::do_return_monitor_check() {
1867 if (_monitor_top > 0) {
1868 // The monitor stack must be empty when we leave the method
1869 // for the monitors to be properly matched.
1870 _monitor_safe = false;
1871
1872 // Since there are no successors to the *return bytecode, it
1873 // isn't necessary to set _monitor_top to bad_monitors.
1874
1875 if (log_is_enabled(Info, monitormismatch)) {
1876 report_monitor_mismatch("non-empty monitor stack at return");
1877 }
1878 }
1879 }
1880
1881 void GenerateOopMap::do_jsr(int targ_bci) {
1882 push(CellTypeState::make_addr(targ_bci));
1883 }
1884
1885
1886
1887 void GenerateOopMap::do_ldc(int bci) {
1888 Bytecode_loadconstant ldc(methodHandle(Thread::current(), method()), bci);
1889 ConstantPool* cp = method()->constants();
1890 constantTag tag = cp->tag_at(ldc.pool_index()); // idx is index in resolved_references
1891 BasicType bt = ldc.result_type();
1892 #ifdef ASSERT
1893 BasicType tag_bt = (tag.is_dynamic_constant() || tag.is_dynamic_constant_in_error()) ? bt : tag.basic_type();
1894 assert(bt == tag_bt, "same result");
1895 #endif
1896 CellTypeState cts;
1897 if (is_reference_type(bt)) { // could be T_ARRAY with condy
1898 assert(!tag.is_string_index() && !tag.is_klass_index(), "Unexpected index tag");
1899 cts = CellTypeState::make_line_ref(bci);
1900 } else {
1901 cts = valCTS;
1902 }
1903 ppush1(cts);
1904 }
1905
1906 void GenerateOopMap::do_multianewarray(int dims, int bci) {
1907 assert(dims >= 1, "sanity check");
1908 for(int i = dims -1; i >=0; i--) {
1909 ppop1(valCTS);
1910 }
1911 ppush1(CellTypeState::make_line_ref(bci));
1912 }
1913
1914 void GenerateOopMap::do_astore(int idx) {
1915 CellTypeState r_or_p = pop();
1916 if (!r_or_p.is_address() && !r_or_p.is_reference()) {
1917 // We actually expected ref or pc, but we only report that we expected a ref. It does not
1918 // really matter (at least for now)
1919 verify_error("wrong type on stack (found: %c, expected: {pr})", r_or_p.to_char());
1920 return;
1921 }
1922 set_var(idx, r_or_p);
1923 }
1924
1925 // Copies bottom/zero terminated CTS string from "src" into "dst".
1926 // Does NOT terminate with a bottom. Returns the number of cells copied.
1927 int GenerateOopMap::copy_cts(CellTypeState *dst, CellTypeState *src) {
1928 int idx = 0;
1929 while (!src[idx].is_bottom()) {
1930 dst[idx] = src[idx];
1931 idx++;
1932 }
1933 return idx;
1934 }
1935
1936 void GenerateOopMap::do_field(int is_get, int is_static, int idx, int bci, Bytecodes::Code bc) {
1937 // Dig up signature for field in constant pool
1938 ConstantPool* cp = method()->constants();
1939 int nameAndTypeIdx = cp->name_and_type_ref_index_at(idx, bc);
1940 int signatureIdx = cp->signature_ref_index_at(nameAndTypeIdx);
1941 Symbol* signature = cp->symbol_at(signatureIdx);
1942
1943 CellTypeState temp[4];
1944 CellTypeState *eff = signature_to_effect(signature, bci, temp);
1945
1946 CellTypeState in[4];
1947 CellTypeState *out;
1948 int i = 0;
1949
1950 if (is_get) {
1951 out = eff;
1952 } else {
1953 out = epsilonCTS;
1954 i = copy_cts(in, eff);
1955 }
1956 if (!is_static) {
1957 in[i++] = CellTypeState::ref;
1958 }
1959 in[i] = CellTypeState::bottom;
1960 assert(i<=3, "sanity check");
1961 pp(in, out);
1962 }
1963
1964 void GenerateOopMap::do_method(int is_static, int idx, int bci, Bytecodes::Code bc) {
1965 // Dig up signature for field in constant pool
1966 ConstantPool* cp = _method->constants();
1967 Symbol* signature = cp->signature_ref_at(idx, bc);
1968
1969 // Parse method signature
1970 CellTypeState out[4];
1971 CellTypeState in[MAXARGSIZE+1]; // Includes result
1972 ComputeCallStack cse(signature);
1973
1974 // Compute return type
1975 int res_length= cse.compute_for_returntype(out);
1976
1977 // Temporary hack.
1978 if (out[0].equal(CellTypeState::ref) && out[1].equal(CellTypeState::bottom)) {
1979 out[0] = CellTypeState::make_line_ref(bci);
1980 }
1981
1982 assert(res_length<=4, "max value should be vv");
1983
1984 // Compute arguments
1985 int arg_length = cse.compute_for_parameters(is_static != 0, in);
1986 assert(arg_length<=MAXARGSIZE, "too many locals");
1987
1988 // Pop arguments
1989 for (int i = arg_length - 1; i >= 0; i--) ppop1(in[i]);// Do args in reverse order.
1990
1991 // Report results
1992 if (_report_result_for_send == true) {
1993 fill_stackmap_for_opcodes(_itr_send, vars(), stack(), _stack_top);
1994 _report_result_for_send = false;
1995 }
1996
1997 // Push return address
1998 ppush(out);
1999 }
2000
2001 // This is used to parse the signature for fields, since they are very simple...
2002 CellTypeState *GenerateOopMap::signature_to_effect(const Symbol* sig, int bci, CellTypeState *out) {
2003 // Object and array
2004 BasicType bt = Signature::basic_type(sig);
2005 if (is_reference_type(bt)) {
2006 out[0] = CellTypeState::make_line_ref(bci);
2007 out[1] = CellTypeState::bottom;
2008 return out;
2009 }
2010 if (is_double_word_type(bt)) return vvCTS; // Long and Double
2011 if (bt == T_VOID) return epsilonCTS; // Void
2012 return vCTS; // Otherwise
2013 }
2014
2015 uint64_t GenerateOopMap::_total_byte_count = 0;
2016 elapsedTimer GenerateOopMap::_total_oopmap_time;
2017
2018 // This function assumes "bcs" is at a "ret" instruction and that the vars
2019 // state is valid for that instruction. Furthermore, the ret instruction
2020 // must be the last instruction in "bb" (we store information about the
2021 // "ret" in "bb").
2022 void GenerateOopMap::ret_jump_targets_do(BytecodeStream *bcs, jmpFct_t jmpFct, int varNo, int *data) {
2023 CellTypeState ra = vars()[varNo];
2024 if (!ra.is_good_address()) {
2025 verify_error("ret returns from two jsr subroutines?");
2026 return;
2027 }
2028 int target = ra.get_info();
2029
2030 RetTableEntry* rtEnt = _rt.find_jsrs_for_target(target);
2031 int bci = bcs->bci();
2032 for (int i = 0; i < rtEnt->nof_jsrs(); i++) {
2033 int target_bci = rtEnt->jsrs(i);
2034 // Make sure a jrtRet does not set the changed bit for dead basicblock.
2035 BasicBlock* jsr_bb = get_basic_block_containing(target_bci - 1);
2036 debug_only(BasicBlock* target_bb = &jsr_bb[1];)
2037 assert(target_bb == get_basic_block_at(target_bci), "wrong calc. of successor basicblock");
2038 bool alive = jsr_bb->is_alive();
2039 if (TraceNewOopMapGeneration) {
2040 tty->print("pc = %d, ret -> %d alive: %s\n", bci, target_bci, alive ? "true" : "false");
2041 }
2042 if (alive) jmpFct(this, target_bci, data);
2043 }
2044 }
2045
2046 //
2047 // Debug method
2048 //
2049 char* GenerateOopMap::state_vec_to_string(CellTypeState* vec, int len) {
2050 #ifdef ASSERT
2051 int checklen = MAX3(_max_locals, _max_stack, _max_monitors) + 1;
2052 assert(len < checklen, "state_vec_buf overflow");
2053 #endif
2054 for (int i = 0; i < len; i++) _state_vec_buf[i] = vec[i].to_char();
2055 _state_vec_buf[len] = 0;
2056 return _state_vec_buf;
2057 }
2058
2059 void GenerateOopMap::print_time() {
2060 tty->print_cr ("Accumulated oopmap times:");
2061 tty->print_cr ("---------------------------");
2062 tty->print_cr (" Total : %3.3f sec.", GenerateOopMap::_total_oopmap_time.seconds());
2063 tty->print_cr (" (%3.0f bytecodes per sec) ",
2064 (double)GenerateOopMap::_total_byte_count / GenerateOopMap::_total_oopmap_time.seconds());
2065 }
2066
2067 //
2068 // ============ Main Entry Point ===========
2069 //
2070 GenerateOopMap::GenerateOopMap(const methodHandle& method) {
2071 // We have to initialize all variables here, that can be queried directly
2072 _method = method;
2073 _max_locals=0;
2074 _init_vars = nullptr;
2075
2076 #ifndef PRODUCT
2077 // If we are doing a detailed trace, include the regular trace information.
2078 if (TraceNewOopMapGenerationDetailed) {
2079 TraceNewOopMapGeneration = true;
2080 }
2081 #endif
2082 }
2083
2084 bool GenerateOopMap::compute_map(Thread* current) {
2085 #ifndef PRODUCT
2086 if (TimeOopMap2) {
2087 method()->print_short_name(tty);
2088 tty->print(" ");
2089 }
2090 if (TimeOopMap) {
2091 _total_byte_count += method()->code_size();
2092 }
2093 #endif
2094 TraceTime t_single("oopmap time", TimeOopMap2);
2095 TraceTime t_all(nullptr, &_total_oopmap_time, TimeOopMap);
2096
2097 // Initialize values
2098 _got_error = false;
2099 _conflict = false;
2100 _max_locals = method()->max_locals();
2101 _max_stack = method()->max_stack();
2102 _has_exceptions = (method()->has_exception_handler());
2103 _nof_refval_conflicts = 0;
2104 _init_vars = new GrowableArray<intptr_t>(5); // There are seldom more than 5 init_vars
2105 _report_result = false;
2106 _report_result_for_send = false;
2107 _new_var_map = nullptr;
2108 _ret_adr_tos = new GrowableArray<int>(5); // 5 seems like a good number;
2109 _did_rewriting = false;
2110 _did_relocation = false;
2111
2112 if (TraceNewOopMapGeneration) {
2113 tty->print("Method name: %s\n", method()->name()->as_C_string());
2114 if (Verbose) {
2115 _method->print_codes();
2116 tty->print_cr("Exception table:");
2117 ExceptionTable excps(method());
2118 for(int i = 0; i < excps.length(); i ++) {
2119 tty->print_cr("[%d - %d] -> %d",
2120 excps.start_pc(i), excps.end_pc(i), excps.handler_pc(i));
2121 }
2122 }
2123 }
2124
2125 // if no code - do nothing
2126 // compiler needs info
2127 if (method()->code_size() == 0 || _max_locals + method()->max_stack() == 0) {
2128 fill_stackmap_prolog(0);
2129 fill_stackmap_epilog();
2130 return true;
2131 }
2132 // Step 1: Compute all jump targets and their return value
2133 if (!_got_error)
2134 _rt.compute_ret_table(_method);
2135
2136 // Step 2: Find all basic blocks and count GC points
2137 if (!_got_error)
2138 mark_bbheaders_and_count_gc_points();
2139
2140 // Step 3: Calculate stack maps
2141 if (!_got_error)
2142 do_interpretation();
2143
2144 // Step 4:Return results
2145 if (!_got_error && report_results())
2146 report_result();
2147
2148 return !_got_error;
2149 }
2150
2151 // Error handling methods
2152 //
2153 // If we compute from a suitable JavaThread then we create an exception for the GenerateOopMap
2154 // calling code to retrieve (via exception()) and throw if desired (in most cases errors are ignored).
2155 // Otherwise it is considered a fatal error to hit malformed bytecode.
2156 void GenerateOopMap::error_work(const char *format, va_list ap) {
2157 _got_error = true;
2158 char msg_buffer[512];
2159 os::vsnprintf(msg_buffer, sizeof(msg_buffer), format, ap);
2160 // Append method name
2161 char msg_buffer2[512];
2162 os::snprintf(msg_buffer2, sizeof(msg_buffer2), "%s in method %s", msg_buffer, method()->name()->as_C_string());
2163 Thread* current = Thread::current();
2164 if (current->can_call_java()) {
2165 _exception = Exceptions::new_exception(JavaThread::cast(current),
2166 vmSymbols::java_lang_LinkageError(),
2167 msg_buffer2);
2168 } else {
2169 fatal("%s", msg_buffer2);
2170 }
2171 }
2172
2173 void GenerateOopMap::report_error(const char *format, ...) {
2174 va_list ap;
2175 va_start(ap, format);
2176 error_work(format, ap);
2177 }
2178
2179 void GenerateOopMap::verify_error(const char *format, ...) {
2180 // We do not distinguish between different types of errors for verification
2181 // errors. Let the verifier give a better message.
2182 report_error("Illegal class file encountered. Try running with -Xverify:all");
2183 }
2184
2185 //
2186 // Report result opcodes
2187 //
2188 void GenerateOopMap::report_result() {
2189
2190 if (TraceNewOopMapGeneration) tty->print_cr("Report result pass");
2191
2192 // We now want to report the result of the parse
2193 _report_result = true;
2194
2195 // Prolog code
2196 fill_stackmap_prolog(_gc_points);
2197
2198 // Mark everything changed, then do one interpretation pass.
2199 for (int i = 0; i<_bb_count; i++) {
2200 if (_basic_blocks[i].is_reachable()) {
2201 _basic_blocks[i].set_changed(true);
2202 interp_bb(&_basic_blocks[i]);
2203 }
2204 }
2205
2206 // Note: Since we are skipping dead-code when we are reporting results, then
2207 // the no. of encountered gc-points might be fewer than the previously number
2208 // we have counted. (dead-code is a pain - it should be removed before we get here)
2209 fill_stackmap_epilog();
2210
2211 // Report initvars
2212 fill_init_vars(_init_vars);
2213
2214 _report_result = false;
2215 }
2216
2217 void GenerateOopMap::result_for_basicblock(int bci) {
2218 if (TraceNewOopMapGeneration) tty->print_cr("Report result pass for basicblock");
2219
2220 // We now want to report the result of the parse
2221 _report_result = true;
2222
2223 // Find basicblock and report results
2224 BasicBlock* bb = get_basic_block_containing(bci);
2225 guarantee(bb != nullptr, "no basic block for bci");
2226 assert(bb->is_reachable(), "getting result from unreachable basicblock");
2227 bb->set_changed(true);
2228 interp_bb(bb);
2229 }
2230
2231 //
2232 // Conflict handling code
2233 //
2234
2235 void GenerateOopMap::record_refval_conflict(int varNo) {
2236 assert(varNo>=0 && varNo< _max_locals, "index out of range");
2237
2238 if (TraceOopMapRewrites) {
2239 tty->print("### Conflict detected (local no: %d)\n", varNo);
2240 }
2241
2242 if (!_new_var_map) {
2243 _new_var_map = NEW_RESOURCE_ARRAY(int, _max_locals);
2244 for (int k = 0; k < _max_locals; k++) _new_var_map[k] = k;
2245 }
2246
2247 if ( _new_var_map[varNo] == varNo) {
2248 // Check if max. number of locals has been reached
2249 if (_max_locals + _nof_refval_conflicts >= MAX_LOCAL_VARS) {
2250 report_error("Rewriting exceeded local variable limit");
2251 return;
2252 }
2253 _new_var_map[varNo] = _max_locals + _nof_refval_conflicts;
2254 _nof_refval_conflicts++;
2255 }
2256 }
2257
2258 void GenerateOopMap::rewrite_refval_conflicts()
2259 {
2260 // We can get here two ways: Either a rewrite conflict was detected, or
2261 // an uninitialize reference was detected. In the second case, we do not
2262 // do any rewriting, we just want to recompute the reference set with the
2263 // new information
2264
2265 int nof_conflicts = 0; // Used for debugging only
2266
2267 if ( _nof_refval_conflicts == 0 )
2268 return;
2269
2270 // Check if rewrites are allowed in this parse.
2271 if (!allow_rewrites()) {
2272 fatal("Rewriting method not allowed at this stage");
2273 }
2274
2275
2276 // Tracing flag
2277 _did_rewriting = true;
2278
2279 if (TraceOopMapRewrites) {
2280 tty->print_cr("ref/value conflict for method %s - bytecodes are getting rewritten", method()->name()->as_C_string());
2281 method()->print();
2282 method()->print_codes();
2283 }
2284
2285 assert(_new_var_map!=nullptr, "nothing to rewrite");
2286 assert(_conflict==true, "We should not be here");
2287
2288 compute_ret_adr_at_TOS();
2289 if (!_got_error) {
2290 for (int k = 0; k < _max_locals && !_got_error; k++) {
2291 if (_new_var_map[k] != k) {
2292 if (TraceOopMapRewrites) {
2293 tty->print_cr("Rewriting: %d -> %d", k, _new_var_map[k]);
2294 }
2295 rewrite_refval_conflict(k, _new_var_map[k]);
2296 if (_got_error) return;
2297 nof_conflicts++;
2298 }
2299 }
2300 }
2301
2302 assert(nof_conflicts == _nof_refval_conflicts, "sanity check");
2303
2304 // Adjust the number of locals
2305 method()->set_max_locals(_max_locals+_nof_refval_conflicts);
2306 _max_locals += _nof_refval_conflicts;
2307
2308 // That was that...
2309 _new_var_map = nullptr;
2310 _nof_refval_conflicts = 0;
2311 }
2312
2313 void GenerateOopMap::rewrite_refval_conflict(int from, int to) {
2314 bool startOver;
2315 do {
2316 // Make sure that the BytecodeStream is constructed in the loop, since
2317 // during rewriting a new method is going to be used, and the next time
2318 // around we want to use that.
2319 BytecodeStream bcs(_method);
2320 startOver = false;
2321
2322 while( !startOver && !_got_error &&
2323 // test bcs in case method changed and it became invalid
2324 bcs.next() >=0) {
2325 startOver = rewrite_refval_conflict_inst(&bcs, from, to);
2326 }
2327 } while (startOver && !_got_error);
2328 }
2329
2330 /* If the current instruction is one that uses local variable "from"
2331 in a ref way, change it to use "to". There's a subtle reason why we
2332 renumber the ref uses and not the non-ref uses: non-ref uses may be
2333 2 slots wide (double, long) which would necessitate keeping track of
2334 whether we should add one or two variables to the method. If the change
2335 affected the width of some instruction, returns "TRUE"; otherwise, returns "FALSE".
2336 Another reason for moving ref's value is for solving (addr, ref) conflicts, which
2337 both uses aload/astore methods.
2338 */
2339 bool GenerateOopMap::rewrite_refval_conflict_inst(BytecodeStream *itr, int from, int to) {
2340 Bytecodes::Code bc = itr->code();
2341 int index;
2342 int bci = itr->bci();
2343
2344 if (is_aload(itr, &index) && index == from) {
2345 if (TraceOopMapRewrites) {
2346 tty->print_cr("Rewriting aload at bci: %d", bci);
2347 }
2348 return rewrite_load_or_store(itr, Bytecodes::_aload, Bytecodes::_aload_0, to);
2349 }
2350
2351 if (is_astore(itr, &index) && index == from) {
2352 if (!stack_top_holds_ret_addr(bci)) {
2353 if (TraceOopMapRewrites) {
2354 tty->print_cr("Rewriting astore at bci: %d", bci);
2355 }
2356 return rewrite_load_or_store(itr, Bytecodes::_astore, Bytecodes::_astore_0, to);
2357 } else {
2358 if (TraceOopMapRewrites) {
2359 tty->print_cr("Suppress rewriting of astore at bci: %d", bci);
2360 }
2361 }
2362 }
2363
2364 return false;
2365 }
2366
2367 // The argument to this method is:
2368 // bc : Current bytecode
2369 // bcN : either _aload or _astore
2370 // bc0 : either _aload_0 or _astore_0
2371 bool GenerateOopMap::rewrite_load_or_store(BytecodeStream *bcs, Bytecodes::Code bcN, Bytecodes::Code bc0, unsigned int varNo) {
2372 assert(bcN == Bytecodes::_astore || bcN == Bytecodes::_aload, "wrong argument (bcN)");
2373 assert(bc0 == Bytecodes::_astore_0 || bc0 == Bytecodes::_aload_0, "wrong argument (bc0)");
2374 int ilen = Bytecodes::length_at(_method(), bcs->bcp());
2375 int newIlen;
2376
2377 if (ilen == 4) {
2378 // Original instruction was wide; keep it wide for simplicity
2379 newIlen = 4;
2380 } else if (varNo < 4)
2381 newIlen = 1;
2382 else if (varNo >= 256)
2383 newIlen = 4;
2384 else
2385 newIlen = 2;
2386
2387 // If we need to relocate in order to patch the byte, we
2388 // do the patching in a temp. buffer, that is passed to the reloc.
2389 // The patching of the bytecode stream is then done by the Relocator.
2390 // This is necessary, since relocating the instruction at a certain bci, might
2391 // also relocate that instruction, e.g., if a _goto before it gets widen to a _goto_w.
2392 // Hence, we do not know which bci to patch after relocation.
2393
2394 assert(newIlen <= 4, "sanity check");
2395 u_char inst_buffer[4]; // Max. instruction size is 4.
2396 address bcp;
2397
2398 if (newIlen != ilen) {
2399 // Relocation needed do patching in temp. buffer
2400 bcp = (address)inst_buffer;
2401 } else {
2402 bcp = _method->bcp_from(bcs->bci());
2403 }
2404
2405 // Patch either directly in Method* or in temp. buffer
2406 if (newIlen == 1) {
2407 assert(varNo < 4, "varNo too large");
2408 *bcp = (u1)(bc0 + varNo);
2409 } else if (newIlen == 2) {
2410 assert(varNo < 256, "2-byte index needed!");
2411 *(bcp + 0) = bcN;
2412 *(bcp + 1) = (u1)varNo;
2413 } else {
2414 assert(newIlen == 4, "Wrong instruction length");
2415 *(bcp + 0) = Bytecodes::_wide;
2416 *(bcp + 1) = bcN;
2417 Bytes::put_Java_u2(bcp+2, (u2)varNo);
2418 }
2419
2420 if (newIlen != ilen) {
2421 expand_current_instr(bcs->bci(), ilen, newIlen, inst_buffer);
2422 }
2423
2424
2425 return (newIlen != ilen);
2426 }
2427
2428 class RelocCallback : public RelocatorListener {
2429 private:
2430 GenerateOopMap* _gom;
2431 public:
2432 RelocCallback(GenerateOopMap* gom) { _gom = gom; };
2433
2434 // Callback method
2435 virtual void relocated(int bci, int delta, int new_code_length) {
2436 _gom->update_basic_blocks (bci, delta, new_code_length);
2437 _gom->update_ret_adr_at_TOS(bci, delta);
2438 _gom->_rt.update_ret_table (bci, delta);
2439 }
2440 };
2441
2442 // Returns true if expanding was successful. Otherwise, reports an error and
2443 // returns false.
2444 void GenerateOopMap::expand_current_instr(int bci, int ilen, int newIlen, u_char inst_buffer[]) {
2445 JavaThread* THREAD = JavaThread::current(); // For exception macros.
2446 RelocCallback rcb(this);
2447 Relocator rc(_method, &rcb);
2448 methodHandle m= rc.insert_space_at(bci, newIlen, inst_buffer, THREAD);
2449 if (m.is_null() || HAS_PENDING_EXCEPTION) {
2450 report_error("could not rewrite method - exception occurred or bytecode buffer overflow");
2451 return;
2452 }
2453
2454 // Relocator returns a new method.
2455 _did_relocation = true;
2456 _method = m;
2457 }
2458
2459
2460 bool GenerateOopMap::is_astore(BytecodeStream *itr, int *index) {
2461 Bytecodes::Code bc = itr->code();
2462 switch(bc) {
2463 case Bytecodes::_astore_0:
2464 case Bytecodes::_astore_1:
2465 case Bytecodes::_astore_2:
2466 case Bytecodes::_astore_3:
2467 *index = bc - Bytecodes::_astore_0;
2468 return true;
2469 case Bytecodes::_astore:
2470 *index = itr->get_index();
2471 return true;
2472 default:
2473 return false;
2474 }
2475 }
2476
2477 bool GenerateOopMap::is_aload(BytecodeStream *itr, int *index) {
2478 Bytecodes::Code bc = itr->code();
2479 switch(bc) {
2480 case Bytecodes::_aload_0:
2481 case Bytecodes::_aload_1:
2482 case Bytecodes::_aload_2:
2483 case Bytecodes::_aload_3:
2484 *index = bc - Bytecodes::_aload_0;
2485 return true;
2486
2487 case Bytecodes::_aload:
2488 *index = itr->get_index();
2489 return true;
2490
2491 default:
2492 return false;
2493 }
2494 }
2495
2496
2497 // Return true iff the top of the operand stack holds a return address at
2498 // the current instruction
2499 bool GenerateOopMap::stack_top_holds_ret_addr(int bci) {
2500 for(int i = 0; i < _ret_adr_tos->length(); i++) {
2501 if (_ret_adr_tos->at(i) == bci)
2502 return true;
2503 }
2504
2505 return false;
2506 }
2507
2508 void GenerateOopMap::compute_ret_adr_at_TOS() {
2509 assert(_ret_adr_tos != nullptr, "must be initialized");
2510 _ret_adr_tos->clear();
2511
2512 for (int i = 0; i < bb_count(); i++) {
2513 BasicBlock* bb = &_basic_blocks[i];
2514
2515 // Make sure to only check basicblocks that are reachable
2516 if (bb->is_reachable()) {
2517
2518 // For each Basic block we check all instructions
2519 BytecodeStream bcs(_method);
2520 bcs.set_interval(bb->_bci, next_bb_start_pc(bb));
2521
2522 restore_state(bb);
2523
2524 while (bcs.next()>=0 && !_got_error) {
2525 // TDT: should this be is_good_address() ?
2526 if (_stack_top > 0 && stack()[_stack_top-1].is_address()) {
2527 _ret_adr_tos->append(bcs.bci());
2528 if (TraceNewOopMapGeneration) {
2529 tty->print_cr("Ret_adr TOS at bci: %d", bcs.bci());
2530 }
2531 }
2532 interp1(&bcs);
2533 }
2534 }
2535 }
2536 }
2537
2538 void GenerateOopMap::update_ret_adr_at_TOS(int bci, int delta) {
2539 for(int i = 0; i < _ret_adr_tos->length(); i++) {
2540 int v = _ret_adr_tos->at(i);
2541 if (v > bci) _ret_adr_tos->at_put(i, v + delta);
2542 }
2543 }
2544
2545 // ===================================================================
2546
2547 #ifndef PRODUCT
2548 int ResolveOopMapConflicts::_nof_invocations = 0;
2549 int ResolveOopMapConflicts::_nof_rewrites = 0;
2550 int ResolveOopMapConflicts::_nof_relocations = 0;
2551 #endif
2552
2553 methodHandle ResolveOopMapConflicts::do_potential_rewrite(TRAPS) {
2554 if (!compute_map(THREAD)) {
2555 THROW_HANDLE_(exception(), methodHandle());
2556 }
2557
2558 #ifndef PRODUCT
2559 // Tracking and statistics
2560 if (PrintRewrites) {
2561 _nof_invocations++;
2562 if (did_rewriting()) {
2563 _nof_rewrites++;
2564 if (did_relocation()) _nof_relocations++;
2565 tty->print("Method was rewritten %s: ", (did_relocation()) ? "and relocated" : "");
2566 method()->print_value(); tty->cr();
2567 tty->print_cr("Cand.: %d rewrts: %d (%d%%) reloc.: %d (%d%%)",
2568 _nof_invocations,
2569 _nof_rewrites, (_nof_rewrites * 100) / _nof_invocations,
2570 _nof_relocations, (_nof_relocations * 100) / _nof_invocations);
2571 }
2572 }
2573 #endif
2574 return methodHandle(THREAD, method());
2575 }