1 /*
2 * Copyright (c) 1997, 2010, 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 "interpreter/bytecodeStream.hpp"
27 #include "oops/generateOopMap.hpp"
28 #include "oops/oop.inline.hpp"
29 #include "oops/symbolOop.hpp"
30 #include "runtime/handles.inline.hpp"
31 #include "runtime/java.hpp"
32 #include "runtime/relocator.hpp"
33 #include "utilities/bitMap.inline.hpp"
34
35 //
36 //
37 // Compute stack layouts for each instruction in method.
38 //
39 // Problems:
40 // - What to do about jsr with different types of local vars?
41 // Need maps that are conditional on jsr path?
42 // - Jsr and exceptions should be done more efficiently (the retAddr stuff)
43 //
44 // Alternative:
45 // - Could extend verifier to provide this information.
46 // For: one fewer abstract interpreter to maintain. Against: the verifier
47 // solves a bigger problem so slower (undesirable to force verification of
48 // everything?).
49 //
50 // Algorithm:
51 // Partition bytecodes into basic blocks
52 // For each basic block: store entry state (vars, stack). For instructions
53 // inside basic blocks we do not store any state (instead we recompute it
54 // from state produced by previous instruction).
55 //
56 // Perform abstract interpretation of bytecodes over this lattice:
57 //
58 // _--'#'--_
59 // / / \ \
60 // / / \ \
61 // / | | \
62 // 'r' 'v' 'p' ' '
63 // \ | | /
64 // \ \ / /
65 // \ \ / /
66 // -- '@' --
67 //
68 // '#' top, result of conflict merge
69 // 'r' reference type
70 // 'v' value type
71 // 'p' pc type for jsr/ret
72 // ' ' uninitialized; never occurs on operand stack in Java
73 // '@' bottom/unexecuted; initial state each bytecode.
74 //
75 // Basic block headers are the only merge points. We use this iteration to
76 // compute the information:
77 //
78 // find basic blocks;
79 // initialize them with uninitialized state;
80 // initialize first BB according to method signature;
81 // mark first BB changed
82 // while (some BB is changed) do {
83 // perform abstract interpration of all bytecodes in BB;
84 // merge exit state of BB into entry state of all successor BBs,
85 // noting if any of these change;
86 // }
87 //
88 // One additional complication is necessary. The jsr instruction pushes
89 // a return PC on the stack (a 'p' type in the abstract interpretation).
90 // To be able to process "ret" bytecodes, we keep track of these return
91 // PC's in a 'retAddrs' structure in abstract interpreter context (when
92 // processing a "ret" bytecodes, it is not sufficient to know that it gets
93 // an argument of the right type 'p'; we need to know which address it
94 // returns to).
95 //
96 // (Note this comment is borrowed form the original author of the algorithm)
97
98 // ComputeCallStack
99 //
100 // Specialization of SignatureIterator - compute the effects of a call
101 //
102 class ComputeCallStack : public SignatureIterator {
103 CellTypeState *_effect;
104 int _idx;
105
106 void setup();
107 void set(CellTypeState state) { _effect[_idx++] = state; }
108 int length() { return _idx; };
109
110 virtual void do_bool () { set(CellTypeState::value); };
111 virtual void do_char () { set(CellTypeState::value); };
112 virtual void do_float () { set(CellTypeState::value); };
113 virtual void do_byte () { set(CellTypeState::value); };
114 virtual void do_short () { set(CellTypeState::value); };
115 virtual void do_int () { set(CellTypeState::value); };
116 virtual void do_void () { set(CellTypeState::bottom);};
117 virtual void do_object(int begin, int end) { set(CellTypeState::ref); };
118 virtual void do_array (int begin, int end) { set(CellTypeState::ref); };
119
120 void do_double() { set(CellTypeState::value);
121 set(CellTypeState::value); }
122 void do_long () { set(CellTypeState::value);
123 set(CellTypeState::value); }
124
125 public:
126 ComputeCallStack(symbolOop signature) : SignatureIterator(signature) {};
127
128 // Compute methods
129 int compute_for_parameters(bool is_static, CellTypeState *effect) {
130 _idx = 0;
131 _effect = effect;
132
133 if (!is_static)
134 effect[_idx++] = CellTypeState::ref;
135
136 iterate_parameters();
137
138 return length();
139 };
140
141 int compute_for_returntype(CellTypeState *effect) {
142 _idx = 0;
143 _effect = effect;
144 iterate_returntype();
145 set(CellTypeState::bottom); // Always terminate with a bottom state, so ppush works
146
147 return length();
148 }
149 };
150
151 //=========================================================================================
152 // ComputeEntryStack
153 //
154 // Specialization of SignatureIterator - in order to set up first stack frame
155 //
156 class ComputeEntryStack : public SignatureIterator {
157 CellTypeState *_effect;
158 int _idx;
159
160 void setup();
161 void set(CellTypeState state) { _effect[_idx++] = state; }
162 int length() { return _idx; };
163
164 virtual void do_bool () { set(CellTypeState::value); };
165 virtual void do_char () { set(CellTypeState::value); };
166 virtual void do_float () { set(CellTypeState::value); };
167 virtual void do_byte () { set(CellTypeState::value); };
168 virtual void do_short () { set(CellTypeState::value); };
169 virtual void do_int () { set(CellTypeState::value); };
170 virtual void do_void () { set(CellTypeState::bottom);};
171 virtual void do_object(int begin, int end) { set(CellTypeState::make_slot_ref(_idx)); }
172 virtual void do_array (int begin, int end) { set(CellTypeState::make_slot_ref(_idx)); }
173
174 void do_double() { set(CellTypeState::value);
175 set(CellTypeState::value); }
176 void do_long () { set(CellTypeState::value);
177 set(CellTypeState::value); }
178
179 public:
180 ComputeEntryStack(symbolOop signature) : SignatureIterator(signature) {};
181
182 // Compute methods
183 int compute_for_parameters(bool is_static, CellTypeState *effect) {
184 _idx = 0;
185 _effect = effect;
186
187 if (!is_static)
188 effect[_idx++] = CellTypeState::make_slot_ref(0);
189
190 iterate_parameters();
191
192 return length();
193 };
194
195 int compute_for_returntype(CellTypeState *effect) {
196 _idx = 0;
197 _effect = effect;
198 iterate_returntype();
199 set(CellTypeState::bottom); // Always terminate with a bottom state, so ppush works
200
201 return length();
202 }
203 };
204
205 //=====================================================================================
206 //
207 // Implementation of RetTable/RetTableEntry
208 //
209 // Contains function to itereate through all bytecodes
210 // and find all return entry points
211 //
212 int RetTable::_init_nof_entries = 10;
213 int RetTableEntry::_init_nof_jsrs = 5;
214
215 void RetTableEntry::add_delta(int bci, int delta) {
216 if (_target_bci > bci) _target_bci += delta;
217
218 for (int k = 0; k < _jsrs->length(); k++) {
219 int jsr = _jsrs->at(k);
220 if (jsr > bci) _jsrs->at_put(k, jsr+delta);
221 }
222 }
223
224 void RetTable::compute_ret_table(methodHandle method) {
225 BytecodeStream i(method);
226 Bytecodes::Code bytecode;
227
228 while( (bytecode = i.next()) >= 0) {
229 switch (bytecode) {
230 case Bytecodes::_jsr:
231 add_jsr(i.next_bci(), i.dest());
232 break;
233 case Bytecodes::_jsr_w:
234 add_jsr(i.next_bci(), i.dest_w());
235 break;
236 }
237 }
238 }
239
240 void RetTable::add_jsr(int return_bci, int target_bci) {
241 RetTableEntry* entry = _first;
242
243 // Scan table for entry
244 for (;entry && entry->target_bci() != target_bci; entry = entry->next());
245
246 if (!entry) {
247 // Allocate new entry and put in list
248 entry = new RetTableEntry(target_bci, _first);
249 _first = entry;
250 }
251
252 // Now "entry" is set. Make sure that the entry is initialized
253 // and has room for the new jsr.
254 entry->add_jsr(return_bci);
255 }
256
257 RetTableEntry* RetTable::find_jsrs_for_target(int targBci) {
258 RetTableEntry *cur = _first;
259
260 while(cur) {
261 assert(cur->target_bci() != -1, "sanity check");
262 if (cur->target_bci() == targBci) return cur;
263 cur = cur->next();
264 }
265 ShouldNotReachHere();
266 return NULL;
267 }
268
269 // The instruction at bci is changing size by "delta". Update the return map.
270 void RetTable::update_ret_table(int bci, int delta) {
271 RetTableEntry *cur = _first;
272 while(cur) {
273 cur->add_delta(bci, delta);
274 cur = cur->next();
275 }
276 }
277
278 //
279 // Celltype state
280 //
281
282 CellTypeState CellTypeState::bottom = CellTypeState::make_bottom();
283 CellTypeState CellTypeState::uninit = CellTypeState::make_any(uninit_value);
284 CellTypeState CellTypeState::ref = CellTypeState::make_any(ref_conflict);
285 CellTypeState CellTypeState::value = CellTypeState::make_any(val_value);
286 CellTypeState CellTypeState::refUninit = CellTypeState::make_any(ref_conflict | uninit_value);
287 CellTypeState CellTypeState::top = CellTypeState::make_top();
288 CellTypeState CellTypeState::addr = CellTypeState::make_any(addr_conflict);
289
290 // Commonly used constants
291 static CellTypeState epsilonCTS[1] = { CellTypeState::bottom };
292 static CellTypeState refCTS = CellTypeState::ref;
293 static CellTypeState valCTS = CellTypeState::value;
294 static CellTypeState vCTS[2] = { CellTypeState::value, CellTypeState::bottom };
295 static CellTypeState rCTS[2] = { CellTypeState::ref, CellTypeState::bottom };
296 static CellTypeState rrCTS[3] = { CellTypeState::ref, CellTypeState::ref, CellTypeState::bottom };
297 static CellTypeState vrCTS[3] = { CellTypeState::value, CellTypeState::ref, CellTypeState::bottom };
298 static CellTypeState vvCTS[3] = { CellTypeState::value, CellTypeState::value, CellTypeState::bottom };
299 static CellTypeState rvrCTS[4] = { CellTypeState::ref, CellTypeState::value, CellTypeState::ref, CellTypeState::bottom };
300 static CellTypeState vvrCTS[4] = { CellTypeState::value, CellTypeState::value, CellTypeState::ref, CellTypeState::bottom };
301 static CellTypeState vvvCTS[4] = { CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::bottom };
302 static CellTypeState vvvrCTS[5] = { CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::ref, CellTypeState::bottom };
303 static CellTypeState vvvvCTS[5] = { CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::bottom };
304
305 char CellTypeState::to_char() const {
306 if (can_be_reference()) {
307 if (can_be_value() || can_be_address())
308 return '#'; // Conflict that needs to be rewritten
309 else
310 return 'r';
311 } else if (can_be_value())
312 return 'v';
313 else if (can_be_address())
314 return 'p';
315 else if (can_be_uninit())
316 return ' ';
317 else
318 return '@';
319 }
320
321
322 // Print a detailed CellTypeState. Indicate all bits that are set. If
323 // the CellTypeState represents an address or a reference, print the
324 // value of the additional information.
325 void CellTypeState::print(outputStream *os) {
326 if (can_be_address()) {
327 os->print("(p");
328 } else {
329 os->print("( ");
330 }
331 if (can_be_reference()) {
332 os->print("r");
333 } else {
334 os->print(" ");
335 }
336 if (can_be_value()) {
337 os->print("v");
338 } else {
339 os->print(" ");
340 }
341 if (can_be_uninit()) {
342 os->print("u|");
343 } else {
344 os->print(" |");
345 }
346 if (is_info_top()) {
347 os->print("Top)");
348 } else if (is_info_bottom()) {
349 os->print("Bot)");
350 } else {
351 if (is_reference()) {
352 int info = get_info();
353 int data = info & ~(ref_not_lock_bit | ref_slot_bit);
354 if (info & ref_not_lock_bit) {
355 // Not a monitor lock reference.
356 if (info & ref_slot_bit) {
357 // slot
358 os->print("slot%d)", data);
359 } else {
360 // line
361 os->print("line%d)", data);
362 }
363 } else {
364 // lock
365 os->print("lock%d)", data);
366 }
367 } else {
368 os->print("%d)", get_info());
369 }
370 }
371 }
372
373 //
374 // Basicblock handling methods
375 //
376
377 void GenerateOopMap ::initialize_bb() {
378 _gc_points = 0;
379 _bb_count = 0;
380 _bb_hdr_bits.clear();
381 _bb_hdr_bits.resize(method()->code_size());
382 }
383
384 void GenerateOopMap::bb_mark_fct(GenerateOopMap *c, int bci, int *data) {
385 assert(bci>= 0 && bci < c->method()->code_size(), "index out of bounds");
386 if (c->is_bb_header(bci))
387 return;
388
389 if (TraceNewOopMapGeneration) {
390 tty->print_cr("Basicblock#%d begins at: %d", c->_bb_count, bci);
391 }
392 c->set_bbmark_bit(bci);
393 c->_bb_count++;
394 }
395
396
397 void GenerateOopMap::mark_bbheaders_and_count_gc_points() {
398 initialize_bb();
399
400 bool fellThrough = false; // False to get first BB marked.
401
402 // First mark all exception handlers as start of a basic-block
403 typeArrayOop excps = method()->exception_table();
404 for(int i = 0; i < excps->length(); i += 4) {
405 int handler_pc_idx = i+2;
406 bb_mark_fct(this, excps->int_at(handler_pc_idx), NULL);
407 }
408
409 // Then iterate through the code
410 BytecodeStream bcs(_method);
411 Bytecodes::Code bytecode;
412
413 while( (bytecode = bcs.next()) >= 0) {
414 int bci = bcs.bci();
415
416 if (!fellThrough)
417 bb_mark_fct(this, bci, NULL);
418
419 fellThrough = jump_targets_do(&bcs, &GenerateOopMap::bb_mark_fct, NULL);
420
421 /* We will also mark successors of jsr's as basic block headers. */
422 switch (bytecode) {
423 case Bytecodes::_jsr:
424 assert(!fellThrough, "should not happen");
425 bb_mark_fct(this, bci + Bytecodes::length_for(bytecode), NULL);
426 break;
427 case Bytecodes::_jsr_w:
428 assert(!fellThrough, "should not happen");
429 bb_mark_fct(this, bci + Bytecodes::length_for(bytecode), NULL);
430 break;
431 }
432
433 if (possible_gc_point(&bcs))
434 _gc_points++;
435 }
436 }
437
438 void GenerateOopMap::reachable_basicblock(GenerateOopMap *c, int bci, int *data) {
439 assert(bci>= 0 && bci < c->method()->code_size(), "index out of bounds");
440 BasicBlock* bb = c->get_basic_block_at(bci);
441 if (bb->is_dead()) {
442 bb->mark_as_alive();
443 *data = 1; // Mark basicblock as changed
444 }
445 }
446
447
448 void GenerateOopMap::mark_reachable_code() {
449 int change = 1; // int to get function pointers to work
450
451 // Mark entry basic block as alive and all exception handlers
452 _basic_blocks[0].mark_as_alive();
453 typeArrayOop excps = method()->exception_table();
454 for(int i = 0; i < excps->length(); i += 4) {
455 int handler_pc_idx = i+2;
456 BasicBlock *bb = get_basic_block_at(excps->int_at(handler_pc_idx));
457 // If block is not already alive (due to multiple exception handlers to same bb), then
458 // make it alive
459 if (bb->is_dead()) bb->mark_as_alive();
460 }
461
462 BytecodeStream bcs(_method);
463
464 // Iterate through all basic blocks until we reach a fixpoint
465 while (change) {
466 change = 0;
467
468 for (int i = 0; i < _bb_count; i++) {
469 BasicBlock *bb = &_basic_blocks[i];
470 if (bb->is_alive()) {
471 // Position bytecodestream at last bytecode in basicblock
472 bcs.set_start(bb->_end_bci);
473 bcs.next();
474 Bytecodes::Code bytecode = bcs.code();
475 int bci = bcs.bci();
476 assert(bci == bb->_end_bci, "wrong bci");
477
478 bool fell_through = jump_targets_do(&bcs, &GenerateOopMap::reachable_basicblock, &change);
479
480 // We will also mark successors of jsr's as alive.
481 switch (bytecode) {
482 case Bytecodes::_jsr:
483 case Bytecodes::_jsr_w:
484 assert(!fell_through, "should not happen");
485 reachable_basicblock(this, bci + Bytecodes::length_for(bytecode), &change);
486 break;
487 }
488 if (fell_through) {
489 // Mark successor as alive
490 if (bb[1].is_dead()) {
491 bb[1].mark_as_alive();
492 change = 1;
493 }
494 }
495 }
496 }
497 }
498 }
499
500 /* If the current instruction in "c" has no effect on control flow,
501 returns "true". Otherwise, calls "jmpFct" one or more times, with
502 "c", an appropriate "pcDelta", and "data" as arguments, then
503 returns "false". There is one exception: if the current
504 instruction is a "ret", returns "false" without calling "jmpFct".
505 Arrangements for tracking the control flow of a "ret" must be made
506 externally. */
507 bool GenerateOopMap::jump_targets_do(BytecodeStream *bcs, jmpFct_t jmpFct, int *data) {
508 int bci = bcs->bci();
509
510 switch (bcs->code()) {
511 case Bytecodes::_ifeq:
512 case Bytecodes::_ifne:
513 case Bytecodes::_iflt:
514 case Bytecodes::_ifge:
515 case Bytecodes::_ifgt:
516 case Bytecodes::_ifle:
517 case Bytecodes::_if_icmpeq:
518 case Bytecodes::_if_icmpne:
519 case Bytecodes::_if_icmplt:
520 case Bytecodes::_if_icmpge:
521 case Bytecodes::_if_icmpgt:
522 case Bytecodes::_if_icmple:
523 case Bytecodes::_if_acmpeq:
524 case Bytecodes::_if_acmpne:
525 case Bytecodes::_ifnull:
526 case Bytecodes::_ifnonnull:
527 (*jmpFct)(this, bcs->dest(), data);
528 (*jmpFct)(this, bci + 3, data);
529 break;
530
531 case Bytecodes::_goto:
532 (*jmpFct)(this, bcs->dest(), data);
533 break;
534 case Bytecodes::_goto_w:
535 (*jmpFct)(this, bcs->dest_w(), data);
536 break;
537 case Bytecodes::_tableswitch:
538 { Bytecode_tableswitch *tableswitch = Bytecode_tableswitch_at(bcs->bcp());
539 int len = tableswitch->length();
540
541 (*jmpFct)(this, bci + tableswitch->default_offset(), data); /* Default. jump address */
542 while (--len >= 0) {
543 (*jmpFct)(this, bci + tableswitch->dest_offset_at(len), data);
544 }
545 break;
546 }
547
548 case Bytecodes::_lookupswitch:
549 { Bytecode_lookupswitch *lookupswitch = Bytecode_lookupswitch_at(bcs->bcp());
550 int npairs = lookupswitch->number_of_pairs();
551 (*jmpFct)(this, bci + lookupswitch->default_offset(), data); /* Default. */
552 while(--npairs >= 0) {
553 LookupswitchPair *pair = lookupswitch->pair_at(npairs);
554 (*jmpFct)(this, bci + pair->offset(), data);
555 }
556 break;
557 }
558 case Bytecodes::_jsr:
559 assert(bcs->is_wide()==false, "sanity check");
560 (*jmpFct)(this, bcs->dest(), data);
561
562
563
564 break;
565 case Bytecodes::_jsr_w:
566 (*jmpFct)(this, bcs->dest_w(), data);
567 break;
568 case Bytecodes::_wide:
569 ShouldNotReachHere();
570 return true;
571 break;
572 case Bytecodes::_athrow:
573 case Bytecodes::_ireturn:
574 case Bytecodes::_lreturn:
575 case Bytecodes::_freturn:
576 case Bytecodes::_dreturn:
577 case Bytecodes::_areturn:
578 case Bytecodes::_return:
579 case Bytecodes::_ret:
580 break;
581 default:
582 return true;
583 }
584 return false;
585 }
586
587 /* Requires "pc" to be the head of a basic block; returns that basic
588 block. */
589 BasicBlock *GenerateOopMap::get_basic_block_at(int bci) const {
590 BasicBlock* bb = get_basic_block_containing(bci);
591 assert(bb->_bci == bci, "should have found BB");
592 return bb;
593 }
594
595 // Requires "pc" to be the start of an instruction; returns the basic
596 // block containing that instruction. */
597 BasicBlock *GenerateOopMap::get_basic_block_containing(int bci) const {
598 BasicBlock *bbs = _basic_blocks;
599 int lo = 0, hi = _bb_count - 1;
600
601 while (lo <= hi) {
602 int m = (lo + hi) / 2;
603 int mbci = bbs[m]._bci;
604 int nbci;
605
606 if ( m == _bb_count-1) {
607 assert( bci >= mbci && bci < method()->code_size(), "sanity check failed");
608 return bbs+m;
609 } else {
610 nbci = bbs[m+1]._bci;
611 }
612
613 if ( mbci <= bci && bci < nbci) {
614 return bbs+m;
615 } else if (mbci < bci) {
616 lo = m + 1;
617 } else {
618 assert(mbci > bci, "sanity check");
619 hi = m - 1;
620 }
621 }
622
623 fatal("should have found BB");
624 return NULL;
625 }
626
627 void GenerateOopMap::restore_state(BasicBlock *bb)
628 {
629 memcpy(_state, bb->_state, _state_len*sizeof(CellTypeState));
630 _stack_top = bb->_stack_top;
631 _monitor_top = bb->_monitor_top;
632 }
633
634 int GenerateOopMap::next_bb_start_pc(BasicBlock *bb) {
635 int bbNum = bb - _basic_blocks + 1;
636 if (bbNum == _bb_count)
637 return method()->code_size();
638
639 return _basic_blocks[bbNum]._bci;
640 }
641
642 //
643 // CellType handling methods
644 //
645
646 void GenerateOopMap::init_state() {
647 _state_len = _max_locals + _max_stack + _max_monitors;
648 _state = NEW_RESOURCE_ARRAY(CellTypeState, _state_len);
649 memset(_state, 0, _state_len * sizeof(CellTypeState));
650 _state_vec_buf = NEW_RESOURCE_ARRAY(char, MAX3(_max_locals, _max_stack, _max_monitors) + 1/*for null terminator char */);
651 }
652
653 void GenerateOopMap::make_context_uninitialized() {
654 CellTypeState* vs = vars();
655
656 for (int i = 0; i < _max_locals; i++)
657 vs[i] = CellTypeState::uninit;
658
659 _stack_top = 0;
660 _monitor_top = 0;
661 }
662
663 int GenerateOopMap::methodsig_to_effect(symbolOop signature, bool is_static, CellTypeState* effect) {
664 ComputeEntryStack ces(signature);
665 return ces.compute_for_parameters(is_static, effect);
666 }
667
668 // Return result of merging cts1 and cts2.
669 CellTypeState CellTypeState::merge(CellTypeState cts, int slot) const {
670 CellTypeState result;
671
672 assert(!is_bottom() && !cts.is_bottom(),
673 "merge of bottom values is handled elsewhere");
674
675 result._state = _state | cts._state;
676
677 // If the top bit is set, we don't need to do any more work.
678 if (!result.is_info_top()) {
679 assert((result.can_be_address() || result.can_be_reference()),
680 "only addresses and references have non-top info");
681
682 if (!equal(cts)) {
683 // The two values being merged are different. Raise to top.
684 if (result.is_reference()) {
685 result = CellTypeState::make_slot_ref(slot);
686 } else {
687 result._state |= info_conflict;
688 }
689 }
690 }
691 assert(result.is_valid_state(), "checking that CTS merge maintains legal state");
692
693 return result;
694 }
695
696 // Merge the variable state for locals and stack from cts into bbts.
697 bool GenerateOopMap::merge_local_state_vectors(CellTypeState* cts,
698 CellTypeState* bbts) {
699 int i;
700 int len = _max_locals + _stack_top;
701 bool change = false;
702
703 for (i = len - 1; i >= 0; i--) {
704 CellTypeState v = cts[i].merge(bbts[i], i);
705 change = change || !v.equal(bbts[i]);
706 bbts[i] = v;
707 }
708
709 return change;
710 }
711
712 // Merge the monitor stack state from cts into bbts.
713 bool GenerateOopMap::merge_monitor_state_vectors(CellTypeState* cts,
714 CellTypeState* bbts) {
715 bool change = false;
716 if (_max_monitors > 0 && _monitor_top != bad_monitors) {
717 // If there are no monitors in the program, or there has been
718 // a monitor matching error before this point in the program,
719 // then we do not merge in the monitor state.
720
721 int base = _max_locals + _max_stack;
722 int len = base + _monitor_top;
723 for (int i = len - 1; i >= base; i--) {
724 CellTypeState v = cts[i].merge(bbts[i], i);
725
726 // Can we prove that, when there has been a change, it will already
727 // have been detected at this point? That would make this equal
728 // check here unnecessary.
729 change = change || !v.equal(bbts[i]);
730 bbts[i] = v;
731 }
732 }
733
734 return change;
735 }
736
737 void GenerateOopMap::copy_state(CellTypeState *dst, CellTypeState *src) {
738 int len = _max_locals + _stack_top;
739 for (int i = 0; i < len; i++) {
740 if (src[i].is_nonlock_reference()) {
741 dst[i] = CellTypeState::make_slot_ref(i);
742 } else {
743 dst[i] = src[i];
744 }
745 }
746 if (_max_monitors > 0 && _monitor_top != bad_monitors) {
747 int base = _max_locals + _max_stack;
748 len = base + _monitor_top;
749 for (int i = base; i < len; i++) {
750 dst[i] = src[i];
751 }
752 }
753 }
754
755
756 // Merge the states for the current block and the next. As long as a
757 // block is reachable the locals and stack must be merged. If the
758 // stack heights don't match then this is a verification error and
759 // it's impossible to interpret the code. Simultaneously monitor
760 // states are being check to see if they nest statically. If monitor
761 // depths match up then their states are merged. Otherwise the
762 // mismatch is simply recorded and interpretation continues since
763 // monitor matching is purely informational and doesn't say anything
764 // about the correctness of the code.
765 void GenerateOopMap::merge_state_into_bb(BasicBlock *bb) {
766 assert(bb->is_alive(), "merging state into a dead basicblock");
767
768 if (_stack_top == bb->_stack_top) {
769 // always merge local state even if monitors don't match.
770 if (merge_local_state_vectors(_state, bb->_state)) {
771 bb->set_changed(true);
772 }
773 if (_monitor_top == bb->_monitor_top) {
774 // monitors still match so continue merging monitor states.
775 if (merge_monitor_state_vectors(_state, bb->_state)) {
776 bb->set_changed(true);
777 }
778 } else {
779 if (TraceMonitorMismatch) {
780 report_monitor_mismatch("monitor stack height merge conflict");
781 }
782 // When the monitor stacks are not matched, we set _monitor_top to
783 // bad_monitors. This signals that, from here on, the monitor stack cannot
784 // be trusted. In particular, monitorexit bytecodes may throw
785 // exceptions. We mark this block as changed so that the change
786 // propagates properly.
787 bb->_monitor_top = bad_monitors;
788 bb->set_changed(true);
789 _monitor_safe = false;
790 }
791 } else if (!bb->is_reachable()) {
792 // First time we look at this BB
793 copy_state(bb->_state, _state);
794 bb->_stack_top = _stack_top;
795 bb->_monitor_top = _monitor_top;
796 bb->set_changed(true);
797 } else {
798 verify_error("stack height conflict: %d vs. %d", _stack_top, bb->_stack_top);
799 }
800 }
801
802 void GenerateOopMap::merge_state(GenerateOopMap *gom, int bci, int* data) {
803 gom->merge_state_into_bb(gom->get_basic_block_at(bci));
804 }
805
806 void GenerateOopMap::set_var(int localNo, CellTypeState cts) {
807 assert(cts.is_reference() || cts.is_value() || cts.is_address(),
808 "wrong celltypestate");
809 if (localNo < 0 || localNo > _max_locals) {
810 verify_error("variable write error: r%d", localNo);
811 return;
812 }
813 vars()[localNo] = cts;
814 }
815
816 CellTypeState GenerateOopMap::get_var(int localNo) {
817 assert(localNo < _max_locals + _nof_refval_conflicts, "variable read error");
818 if (localNo < 0 || localNo > _max_locals) {
819 verify_error("variable read error: r%d", localNo);
820 return valCTS; // just to pick something;
821 }
822 return vars()[localNo];
823 }
824
825 CellTypeState GenerateOopMap::pop() {
826 if ( _stack_top <= 0) {
827 verify_error("stack underflow");
828 return valCTS; // just to pick something
829 }
830 return stack()[--_stack_top];
831 }
832
833 void GenerateOopMap::push(CellTypeState cts) {
834 if ( _stack_top >= _max_stack) {
835 verify_error("stack overflow");
836 return;
837 }
838 stack()[_stack_top++] = cts;
839 }
840
841 CellTypeState GenerateOopMap::monitor_pop() {
842 assert(_monitor_top != bad_monitors, "monitor_pop called on error monitor stack");
843 if (_monitor_top == 0) {
844 // We have detected a pop of an empty monitor stack.
845 _monitor_safe = false;
846 _monitor_top = bad_monitors;
847
848 if (TraceMonitorMismatch) {
849 report_monitor_mismatch("monitor stack underflow");
850 }
851 return CellTypeState::ref; // just to keep the analysis going.
852 }
853 return monitors()[--_monitor_top];
854 }
855
856 void GenerateOopMap::monitor_push(CellTypeState cts) {
857 assert(_monitor_top != bad_monitors, "monitor_push called on error monitor stack");
858 if (_monitor_top >= _max_monitors) {
859 // Some monitorenter is being executed more than once.
860 // This means that the monitor stack cannot be simulated.
861 _monitor_safe = false;
862 _monitor_top = bad_monitors;
863
864 if (TraceMonitorMismatch) {
865 report_monitor_mismatch("monitor stack overflow");
866 }
867 return;
868 }
869 monitors()[_monitor_top++] = cts;
870 }
871
872 //
873 // Interpretation handling methods
874 //
875
876 void GenerateOopMap::do_interpretation()
877 {
878 // "i" is just for debugging, so we can detect cases where this loop is
879 // iterated more than once.
880 int i = 0;
881 do {
882 #ifndef PRODUCT
883 if (TraceNewOopMapGeneration) {
884 tty->print("\n\nIteration #%d of do_interpretation loop, method:\n", i);
885 method()->print_name(tty);
886 tty->print("\n\n");
887 }
888 #endif
889 _conflict = false;
890 _monitor_safe = true;
891 // init_state is now called from init_basic_blocks. The length of a
892 // state vector cannot be determined until we have made a pass through
893 // the bytecodes counting the possible monitor entries.
894 if (!_got_error) init_basic_blocks();
895 if (!_got_error) setup_method_entry_state();
896 if (!_got_error) interp_all();
897 if (!_got_error) rewrite_refval_conflicts();
898 i++;
899 } while (_conflict && !_got_error);
900 }
901
902 void GenerateOopMap::init_basic_blocks() {
903 // Note: Could consider reserving only the needed space for each BB's state
904 // (entry stack may not be of maximal height for every basic block).
905 // But cumbersome since we don't know the stack heights yet. (Nor the
906 // monitor stack heights...)
907
908 _basic_blocks = NEW_RESOURCE_ARRAY(BasicBlock, _bb_count);
909
910 // Make a pass through the bytecodes. Count the number of monitorenters.
911 // This can be used an upper bound on the monitor stack depth in programs
912 // which obey stack discipline with their monitor usage. Initialize the
913 // known information about basic blocks.
914 BytecodeStream j(_method);
915 Bytecodes::Code bytecode;
916
917 int bbNo = 0;
918 int monitor_count = 0;
919 int prev_bci = -1;
920 while( (bytecode = j.next()) >= 0) {
921 if (j.code() == Bytecodes::_monitorenter) {
922 monitor_count++;
923 }
924
925 int bci = j.bci();
926 if (is_bb_header(bci)) {
927 // Initialize the basicblock structure
928 BasicBlock *bb = _basic_blocks + bbNo;
929 bb->_bci = bci;
930 bb->_max_locals = _max_locals;
931 bb->_max_stack = _max_stack;
932 bb->set_changed(false);
933 bb->_stack_top = BasicBlock::_dead_basic_block; // Initialize all basicblocks are dead.
934 bb->_monitor_top = bad_monitors;
935
936 if (bbNo > 0) {
937 _basic_blocks[bbNo - 1]._end_bci = prev_bci;
938 }
939
940 bbNo++;
941 }
942 // Remember prevous bci.
943 prev_bci = bci;
944 }
945 // Set
946 _basic_blocks[bbNo-1]._end_bci = prev_bci;
947
948
949 // Check that the correct number of basicblocks was found
950 if (bbNo !=_bb_count) {
951 if (bbNo < _bb_count) {
952 verify_error("jump into the middle of instruction?");
953 return;
954 } else {
955 verify_error("extra basic blocks - should not happen?");
956 return;
957 }
958 }
959
960 _max_monitors = monitor_count;
961
962 // Now that we have a bound on the depth of the monitor stack, we can
963 // initialize the CellTypeState-related information.
964 init_state();
965
966 // We allocate space for all state-vectors for all basicblocks in one huge chuck.
967 // Then in the next part of the code, we set a pointer in each _basic_block that
968 // points to each piece.
969 CellTypeState *basicBlockState = NEW_RESOURCE_ARRAY(CellTypeState, bbNo * _state_len);
970 memset(basicBlockState, 0, bbNo * _state_len * sizeof(CellTypeState));
971
972 // Make a pass over the basicblocks and assign their state vectors.
973 for (int blockNum=0; blockNum < bbNo; blockNum++) {
974 BasicBlock *bb = _basic_blocks + blockNum;
975 bb->_state = basicBlockState + blockNum * _state_len;
976
977 #ifdef ASSERT
978 if (blockNum + 1 < bbNo) {
979 address bcp = _method->bcp_from(bb->_end_bci);
980 int bc_len = Bytecodes::java_length_at(bcp);
981 assert(bb->_end_bci + bc_len == bb[1]._bci, "unmatched bci info in basicblock");
982 }
983 #endif
984 }
985 #ifdef ASSERT
986 { BasicBlock *bb = &_basic_blocks[bbNo-1];
987 address bcp = _method->bcp_from(bb->_end_bci);
988 int bc_len = Bytecodes::java_length_at(bcp);
989 assert(bb->_end_bci + bc_len == _method->code_size(), "wrong end bci");
990 }
991 #endif
992
993 // Mark all alive blocks
994 mark_reachable_code();
995 }
996
997 void GenerateOopMap::setup_method_entry_state() {
998
999 // Initialize all locals to 'uninit' and set stack-height to 0
1000 make_context_uninitialized();
1001
1002 // Initialize CellState type of arguments
1003 methodsig_to_effect(method()->signature(), method()->is_static(), vars());
1004
1005 // If some references must be pre-assigned to null, then set that up
1006 initialize_vars();
1007
1008 // This is the start state
1009 merge_state_into_bb(&_basic_blocks[0]);
1010
1011 assert(_basic_blocks[0].changed(), "we are not getting off the ground");
1012 }
1013
1014 // The instruction at bci is changing size by "delta". Update the basic blocks.
1015 void GenerateOopMap::update_basic_blocks(int bci, int delta,
1016 int new_method_size) {
1017 assert(new_method_size >= method()->code_size() + delta,
1018 "new method size is too small");
1019
1020 BitMap::bm_word_t* new_bb_hdr_bits =
1021 NEW_RESOURCE_ARRAY(BitMap::bm_word_t,
1022 BitMap::word_align_up(new_method_size));
1023 _bb_hdr_bits.set_map(new_bb_hdr_bits);
1024 _bb_hdr_bits.set_size(new_method_size);
1025 _bb_hdr_bits.clear();
1026
1027
1028 for(int k = 0; k < _bb_count; k++) {
1029 if (_basic_blocks[k]._bci > bci) {
1030 _basic_blocks[k]._bci += delta;
1031 _basic_blocks[k]._end_bci += delta;
1032 }
1033 _bb_hdr_bits.at_put(_basic_blocks[k]._bci, true);
1034 }
1035 }
1036
1037 //
1038 // Initvars handling
1039 //
1040
1041 void GenerateOopMap::initialize_vars() {
1042 for (int k = 0; k < _init_vars->length(); k++)
1043 _state[_init_vars->at(k)] = CellTypeState::make_slot_ref(k);
1044 }
1045
1046 void GenerateOopMap::add_to_ref_init_set(int localNo) {
1047
1048 if (TraceNewOopMapGeneration)
1049 tty->print_cr("Added init vars: %d", localNo);
1050
1051 // Is it already in the set?
1052 if (_init_vars->contains(localNo) )
1053 return;
1054
1055 _init_vars->append(localNo);
1056 }
1057
1058 //
1059 // Interpreration code
1060 //
1061
1062 void GenerateOopMap::interp_all() {
1063 bool change = true;
1064
1065 while (change && !_got_error) {
1066 change = false;
1067 for (int i = 0; i < _bb_count && !_got_error; i++) {
1068 BasicBlock *bb = &_basic_blocks[i];
1069 if (bb->changed()) {
1070 if (_got_error) return;
1071 change = true;
1072 bb->set_changed(false);
1073 interp_bb(bb);
1074 }
1075 }
1076 }
1077 }
1078
1079 void GenerateOopMap::interp_bb(BasicBlock *bb) {
1080
1081 // We do not want to do anything in case the basic-block has not been initialized. This
1082 // will happen in the case where there is dead-code hang around in a method.
1083 assert(bb->is_reachable(), "should be reachable or deadcode exist");
1084 restore_state(bb);
1085
1086 BytecodeStream itr(_method);
1087
1088 // Set iterator interval to be the current basicblock
1089 int lim_bci = next_bb_start_pc(bb);
1090 itr.set_interval(bb->_bci, lim_bci);
1091 assert(lim_bci != bb->_bci, "must be at least one instruction in a basicblock");
1092 itr.next(); // read first instruction
1093
1094 // Iterates through all bytecodes except the last in a basic block.
1095 // We handle the last one special, since there is controlflow change.
1096 while(itr.next_bci() < lim_bci && !_got_error) {
1097 if (_has_exceptions || _monitor_top != 0) {
1098 // We do not need to interpret the results of exceptional
1099 // continuation from this instruction when the method has no
1100 // exception handlers and the monitor stack is currently
1101 // empty.
1102 do_exception_edge(&itr);
1103 }
1104 interp1(&itr);
1105 itr.next();
1106 }
1107
1108 // Handle last instruction.
1109 if (!_got_error) {
1110 assert(itr.next_bci() == lim_bci, "must point to end");
1111 if (_has_exceptions || _monitor_top != 0) {
1112 do_exception_edge(&itr);
1113 }
1114 interp1(&itr);
1115
1116 bool fall_through = jump_targets_do(&itr, GenerateOopMap::merge_state, NULL);
1117 if (_got_error) return;
1118
1119 if (itr.code() == Bytecodes::_ret) {
1120 assert(!fall_through, "cannot be set if ret instruction");
1121 // Automatically handles 'wide' ret indicies
1122 ret_jump_targets_do(&itr, GenerateOopMap::merge_state, itr.get_index(), NULL);
1123 } else if (fall_through) {
1124 // Hit end of BB, but the instr. was a fall-through instruction,
1125 // so perform transition as if the BB ended in a "jump".
1126 if (lim_bci != bb[1]._bci) {
1127 verify_error("bytecodes fell through last instruction");
1128 return;
1129 }
1130 merge_state_into_bb(bb + 1);
1131 }
1132 }
1133 }
1134
1135 void GenerateOopMap::do_exception_edge(BytecodeStream* itr) {
1136 // Only check exception edge, if bytecode can trap
1137 if (!Bytecodes::can_trap(itr->code())) return;
1138 switch (itr->code()) {
1139 case Bytecodes::_aload_0:
1140 // These bytecodes can trap for rewriting. We need to assume that
1141 // they do not throw exceptions to make the monitor analysis work.
1142 return;
1143
1144 case Bytecodes::_ireturn:
1145 case Bytecodes::_lreturn:
1146 case Bytecodes::_freturn:
1147 case Bytecodes::_dreturn:
1148 case Bytecodes::_areturn:
1149 case Bytecodes::_return:
1150 // If the monitor stack height is not zero when we leave the method,
1151 // then we are either exiting with a non-empty stack or we have
1152 // found monitor trouble earlier in our analysis. In either case,
1153 // assume an exception could be taken here.
1154 if (_monitor_top == 0) {
1155 return;
1156 }
1157 break;
1158
1159 case Bytecodes::_monitorexit:
1160 // If the monitor stack height is bad_monitors, then we have detected a
1161 // monitor matching problem earlier in the analysis. If the
1162 // monitor stack height is 0, we are about to pop a monitor
1163 // off of an empty stack. In either case, the bytecode
1164 // could throw an exception.
1165 if (_monitor_top != bad_monitors && _monitor_top != 0) {
1166 return;
1167 }
1168 break;
1169 }
1170
1171 if (_has_exceptions) {
1172 int bci = itr->bci();
1173 typeArrayOop exct = method()->exception_table();
1174 for(int i = 0; i< exct->length(); i+=4) {
1175 int start_pc = exct->int_at(i);
1176 int end_pc = exct->int_at(i+1);
1177 int handler_pc = exct->int_at(i+2);
1178 int catch_type = exct->int_at(i+3);
1179
1180 if (start_pc <= bci && bci < end_pc) {
1181 BasicBlock *excBB = get_basic_block_at(handler_pc);
1182 CellTypeState *excStk = excBB->stack();
1183 CellTypeState *cOpStck = stack();
1184 CellTypeState cOpStck_0 = cOpStck[0];
1185 int cOpStackTop = _stack_top;
1186
1187 // Exception stacks are always the same.
1188 assert(method()->max_stack() > 0, "sanity check");
1189
1190 // We remembered the size and first element of "cOpStck"
1191 // above; now we temporarily set them to the appropriate
1192 // values for an exception handler. */
1193 cOpStck[0] = CellTypeState::make_slot_ref(_max_locals);
1194 _stack_top = 1;
1195
1196 merge_state_into_bb(excBB);
1197
1198 // Now undo the temporary change.
1199 cOpStck[0] = cOpStck_0;
1200 _stack_top = cOpStackTop;
1201
1202 // If this is a "catch all" handler, then we do not need to
1203 // consider any additional handlers.
1204 if (catch_type == 0) {
1205 return;
1206 }
1207 }
1208 }
1209 }
1210
1211 // It is possible that none of the exception handlers would have caught
1212 // the exception. In this case, we will exit the method. We must
1213 // ensure that the monitor stack is empty in this case.
1214 if (_monitor_top == 0) {
1215 return;
1216 }
1217
1218 // We pessimistically assume that this exception can escape the
1219 // method. (It is possible that it will always be caught, but
1220 // we don't care to analyse the types of the catch clauses.)
1221
1222 // We don't set _monitor_top to bad_monitors because there are no successors
1223 // to this exceptional exit.
1224
1225 if (TraceMonitorMismatch && _monitor_safe) {
1226 // We check _monitor_safe so that we only report the first mismatched
1227 // exceptional exit.
1228 report_monitor_mismatch("non-empty monitor stack at exceptional exit");
1229 }
1230 _monitor_safe = false;
1231
1232 }
1233
1234 void GenerateOopMap::report_monitor_mismatch(const char *msg) {
1235 #ifndef PRODUCT
1236 tty->print(" Monitor mismatch in method ");
1237 method()->print_short_name(tty);
1238 tty->print_cr(": %s", msg);
1239 #endif
1240 }
1241
1242 void GenerateOopMap::print_states(outputStream *os,
1243 CellTypeState* vec, int num) {
1244 for (int i = 0; i < num; i++) {
1245 vec[i].print(tty);
1246 }
1247 }
1248
1249 // Print the state values at the current bytecode.
1250 void GenerateOopMap::print_current_state(outputStream *os,
1251 BytecodeStream *currentBC,
1252 bool detailed) {
1253
1254 if (detailed) {
1255 os->print(" %4d vars = ", currentBC->bci());
1256 print_states(os, vars(), _max_locals);
1257 os->print(" %s", Bytecodes::name(currentBC->code()));
1258 switch(currentBC->code()) {
1259 case Bytecodes::_invokevirtual:
1260 case Bytecodes::_invokespecial:
1261 case Bytecodes::_invokestatic:
1262 case Bytecodes::_invokedynamic:
1263 case Bytecodes::_invokeinterface:
1264 int idx = currentBC->has_index_u4() ? currentBC->get_index_u4() : currentBC->get_index_u2();
1265 constantPoolOop cp = method()->constants();
1266 int nameAndTypeIdx = cp->name_and_type_ref_index_at(idx);
1267 int signatureIdx = cp->signature_ref_index_at(nameAndTypeIdx);
1268 symbolOop signature = cp->symbol_at(signatureIdx);
1269 os->print("%s", signature->as_C_string());
1270 }
1271 os->cr();
1272 os->print(" stack = ");
1273 print_states(os, stack(), _stack_top);
1274 os->cr();
1275 if (_monitor_top != bad_monitors) {
1276 os->print(" monitors = ");
1277 print_states(os, monitors(), _monitor_top);
1278 } else {
1279 os->print(" [bad monitor stack]");
1280 }
1281 os->cr();
1282 } else {
1283 os->print(" %4d vars = '%s' ", currentBC->bci(), state_vec_to_string(vars(), _max_locals));
1284 os->print(" stack = '%s' ", state_vec_to_string(stack(), _stack_top));
1285 if (_monitor_top != bad_monitors) {
1286 os->print(" monitors = '%s' \t%s", state_vec_to_string(monitors(), _monitor_top), Bytecodes::name(currentBC->code()));
1287 } else {
1288 os->print(" [bad monitor stack]");
1289 }
1290 switch(currentBC->code()) {
1291 case Bytecodes::_invokevirtual:
1292 case Bytecodes::_invokespecial:
1293 case Bytecodes::_invokestatic:
1294 case Bytecodes::_invokedynamic:
1295 case Bytecodes::_invokeinterface:
1296 int idx = currentBC->has_index_u4() ? currentBC->get_index_u4() : currentBC->get_index_u2();
1297 constantPoolOop cp = method()->constants();
1298 int nameAndTypeIdx = cp->name_and_type_ref_index_at(idx);
1299 int signatureIdx = cp->signature_ref_index_at(nameAndTypeIdx);
1300 symbolOop signature = cp->symbol_at(signatureIdx);
1301 os->print("%s", signature->as_C_string());
1302 }
1303 os->cr();
1304 }
1305 }
1306
1307 // Sets the current state to be the state after executing the
1308 // current instruction, starting in the current state.
1309 void GenerateOopMap::interp1(BytecodeStream *itr) {
1310 if (TraceNewOopMapGeneration) {
1311 print_current_state(tty, itr, TraceNewOopMapGenerationDetailed);
1312 }
1313
1314 // Should we report the results? Result is reported *before* the instruction at the current bci is executed.
1315 // However, not for calls. For calls we do not want to include the arguments, so we postpone the reporting until
1316 // they have been popped (in method ppl).
1317 if (_report_result == true) {
1318 switch(itr->code()) {
1319 case Bytecodes::_invokevirtual:
1320 case Bytecodes::_invokespecial:
1321 case Bytecodes::_invokestatic:
1322 case Bytecodes::_invokedynamic:
1323 case Bytecodes::_invokeinterface:
1324 _itr_send = itr;
1325 _report_result_for_send = true;
1326 break;
1327 default:
1328 fill_stackmap_for_opcodes(itr, vars(), stack(), _stack_top);
1329 break;
1330 }
1331 }
1332
1333 // abstract interpretation of current opcode
1334 switch(itr->code()) {
1335 case Bytecodes::_nop: break;
1336 case Bytecodes::_goto: break;
1337 case Bytecodes::_goto_w: break;
1338 case Bytecodes::_iinc: break;
1339 case Bytecodes::_return: do_return_monitor_check();
1340 break;
1341
1342 case Bytecodes::_aconst_null:
1343 case Bytecodes::_new: ppush1(CellTypeState::make_line_ref(itr->bci()));
1344 break;
1345
1346 case Bytecodes::_iconst_m1:
1347 case Bytecodes::_iconst_0:
1348 case Bytecodes::_iconst_1:
1349 case Bytecodes::_iconst_2:
1350 case Bytecodes::_iconst_3:
1351 case Bytecodes::_iconst_4:
1352 case Bytecodes::_iconst_5:
1353 case Bytecodes::_fconst_0:
1354 case Bytecodes::_fconst_1:
1355 case Bytecodes::_fconst_2:
1356 case Bytecodes::_bipush:
1357 case Bytecodes::_sipush: ppush1(valCTS); break;
1358
1359 case Bytecodes::_lconst_0:
1360 case Bytecodes::_lconst_1:
1361 case Bytecodes::_dconst_0:
1362 case Bytecodes::_dconst_1: ppush(vvCTS); break;
1363
1364 case Bytecodes::_ldc2_w: ppush(vvCTS); break;
1365
1366 case Bytecodes::_ldc: do_ldc(itr->get_index(), itr->bci()); break;
1367 case Bytecodes::_ldc_w: do_ldc(itr->get_index_u2(), itr->bci()); break;
1368
1369 case Bytecodes::_iload:
1370 case Bytecodes::_fload: ppload(vCTS, itr->get_index()); break;
1371
1372 case Bytecodes::_lload:
1373 case Bytecodes::_dload: ppload(vvCTS,itr->get_index()); break;
1374
1375 case Bytecodes::_aload: ppload(rCTS, itr->get_index()); break;
1376
1377 case Bytecodes::_iload_0:
1378 case Bytecodes::_fload_0: ppload(vCTS, 0); break;
1379 case Bytecodes::_iload_1:
1380 case Bytecodes::_fload_1: ppload(vCTS, 1); break;
1381 case Bytecodes::_iload_2:
1382 case Bytecodes::_fload_2: ppload(vCTS, 2); break;
1383 case Bytecodes::_iload_3:
1384 case Bytecodes::_fload_3: ppload(vCTS, 3); break;
1385
1386 case Bytecodes::_lload_0:
1387 case Bytecodes::_dload_0: ppload(vvCTS, 0); break;
1388 case Bytecodes::_lload_1:
1389 case Bytecodes::_dload_1: ppload(vvCTS, 1); break;
1390 case Bytecodes::_lload_2:
1391 case Bytecodes::_dload_2: ppload(vvCTS, 2); break;
1392 case Bytecodes::_lload_3:
1393 case Bytecodes::_dload_3: ppload(vvCTS, 3); break;
1394
1395 case Bytecodes::_aload_0: ppload(rCTS, 0); break;
1396 case Bytecodes::_aload_1: ppload(rCTS, 1); break;
1397 case Bytecodes::_aload_2: ppload(rCTS, 2); break;
1398 case Bytecodes::_aload_3: ppload(rCTS, 3); break;
1399
1400 case Bytecodes::_iaload:
1401 case Bytecodes::_faload:
1402 case Bytecodes::_baload:
1403 case Bytecodes::_caload:
1404 case Bytecodes::_saload: pp(vrCTS, vCTS); break;
1405
1406 case Bytecodes::_laload: pp(vrCTS, vvCTS); break;
1407 case Bytecodes::_daload: pp(vrCTS, vvCTS); break;
1408
1409 case Bytecodes::_aaload: pp_new_ref(vrCTS, itr->bci()); break;
1410
1411 case Bytecodes::_istore:
1412 case Bytecodes::_fstore: ppstore(vCTS, itr->get_index()); break;
1413
1414 case Bytecodes::_lstore:
1415 case Bytecodes::_dstore: ppstore(vvCTS, itr->get_index()); break;
1416
1417 case Bytecodes::_astore: do_astore(itr->get_index()); break;
1418
1419 case Bytecodes::_istore_0:
1420 case Bytecodes::_fstore_0: ppstore(vCTS, 0); break;
1421 case Bytecodes::_istore_1:
1422 case Bytecodes::_fstore_1: ppstore(vCTS, 1); break;
1423 case Bytecodes::_istore_2:
1424 case Bytecodes::_fstore_2: ppstore(vCTS, 2); break;
1425 case Bytecodes::_istore_3:
1426 case Bytecodes::_fstore_3: ppstore(vCTS, 3); break;
1427
1428 case Bytecodes::_lstore_0:
1429 case Bytecodes::_dstore_0: ppstore(vvCTS, 0); break;
1430 case Bytecodes::_lstore_1:
1431 case Bytecodes::_dstore_1: ppstore(vvCTS, 1); break;
1432 case Bytecodes::_lstore_2:
1433 case Bytecodes::_dstore_2: ppstore(vvCTS, 2); break;
1434 case Bytecodes::_lstore_3:
1435 case Bytecodes::_dstore_3: ppstore(vvCTS, 3); break;
1436
1437 case Bytecodes::_astore_0: do_astore(0); break;
1438 case Bytecodes::_astore_1: do_astore(1); break;
1439 case Bytecodes::_astore_2: do_astore(2); break;
1440 case Bytecodes::_astore_3: do_astore(3); break;
1441
1442 case Bytecodes::_iastore:
1443 case Bytecodes::_fastore:
1444 case Bytecodes::_bastore:
1445 case Bytecodes::_castore:
1446 case Bytecodes::_sastore: ppop(vvrCTS); break;
1447 case Bytecodes::_lastore:
1448 case Bytecodes::_dastore: ppop(vvvrCTS); break;
1449 case Bytecodes::_aastore: ppop(rvrCTS); break;
1450
1451 case Bytecodes::_pop: ppop_any(1); break;
1452 case Bytecodes::_pop2: ppop_any(2); break;
1453
1454 case Bytecodes::_dup: ppdupswap(1, "11"); break;
1455 case Bytecodes::_dup_x1: ppdupswap(2, "121"); break;
1456 case Bytecodes::_dup_x2: ppdupswap(3, "1321"); break;
1457 case Bytecodes::_dup2: ppdupswap(2, "2121"); break;
1458 case Bytecodes::_dup2_x1: ppdupswap(3, "21321"); break;
1459 case Bytecodes::_dup2_x2: ppdupswap(4, "214321"); break;
1460 case Bytecodes::_swap: ppdupswap(2, "12"); break;
1461
1462 case Bytecodes::_iadd:
1463 case Bytecodes::_fadd:
1464 case Bytecodes::_isub:
1465 case Bytecodes::_fsub:
1466 case Bytecodes::_imul:
1467 case Bytecodes::_fmul:
1468 case Bytecodes::_idiv:
1469 case Bytecodes::_fdiv:
1470 case Bytecodes::_irem:
1471 case Bytecodes::_frem:
1472 case Bytecodes::_ishl:
1473 case Bytecodes::_ishr:
1474 case Bytecodes::_iushr:
1475 case Bytecodes::_iand:
1476 case Bytecodes::_ior:
1477 case Bytecodes::_ixor:
1478 case Bytecodes::_l2f:
1479 case Bytecodes::_l2i:
1480 case Bytecodes::_d2f:
1481 case Bytecodes::_d2i:
1482 case Bytecodes::_fcmpl:
1483 case Bytecodes::_fcmpg: pp(vvCTS, vCTS); break;
1484
1485 case Bytecodes::_ladd:
1486 case Bytecodes::_dadd:
1487 case Bytecodes::_lsub:
1488 case Bytecodes::_dsub:
1489 case Bytecodes::_lmul:
1490 case Bytecodes::_dmul:
1491 case Bytecodes::_ldiv:
1492 case Bytecodes::_ddiv:
1493 case Bytecodes::_lrem:
1494 case Bytecodes::_drem:
1495 case Bytecodes::_land:
1496 case Bytecodes::_lor:
1497 case Bytecodes::_lxor: pp(vvvvCTS, vvCTS); break;
1498
1499 case Bytecodes::_ineg:
1500 case Bytecodes::_fneg:
1501 case Bytecodes::_i2f:
1502 case Bytecodes::_f2i:
1503 case Bytecodes::_i2c:
1504 case Bytecodes::_i2s:
1505 case Bytecodes::_i2b: pp(vCTS, vCTS); break;
1506
1507 case Bytecodes::_lneg:
1508 case Bytecodes::_dneg:
1509 case Bytecodes::_l2d:
1510 case Bytecodes::_d2l: pp(vvCTS, vvCTS); break;
1511
1512 case Bytecodes::_lshl:
1513 case Bytecodes::_lshr:
1514 case Bytecodes::_lushr: pp(vvvCTS, vvCTS); break;
1515
1516 case Bytecodes::_i2l:
1517 case Bytecodes::_i2d:
1518 case Bytecodes::_f2l:
1519 case Bytecodes::_f2d: pp(vCTS, vvCTS); break;
1520
1521 case Bytecodes::_lcmp: pp(vvvvCTS, vCTS); break;
1522 case Bytecodes::_dcmpl:
1523 case Bytecodes::_dcmpg: pp(vvvvCTS, vCTS); break;
1524
1525 case Bytecodes::_ifeq:
1526 case Bytecodes::_ifne:
1527 case Bytecodes::_iflt:
1528 case Bytecodes::_ifge:
1529 case Bytecodes::_ifgt:
1530 case Bytecodes::_ifle:
1531 case Bytecodes::_tableswitch: ppop1(valCTS);
1532 break;
1533 case Bytecodes::_ireturn:
1534 case Bytecodes::_freturn: do_return_monitor_check();
1535 ppop1(valCTS);
1536 break;
1537 case Bytecodes::_if_icmpeq:
1538 case Bytecodes::_if_icmpne:
1539 case Bytecodes::_if_icmplt:
1540 case Bytecodes::_if_icmpge:
1541 case Bytecodes::_if_icmpgt:
1542 case Bytecodes::_if_icmple: ppop(vvCTS);
1543 break;
1544
1545 case Bytecodes::_lreturn: do_return_monitor_check();
1546 ppop(vvCTS);
1547 break;
1548
1549 case Bytecodes::_dreturn: do_return_monitor_check();
1550 ppop(vvCTS);
1551 break;
1552
1553 case Bytecodes::_if_acmpeq:
1554 case Bytecodes::_if_acmpne: ppop(rrCTS); break;
1555
1556 case Bytecodes::_jsr: do_jsr(itr->dest()); break;
1557 case Bytecodes::_jsr_w: do_jsr(itr->dest_w()); break;
1558
1559 case Bytecodes::_getstatic: do_field(true, true,
1560 itr->get_index_u2_cpcache(),
1561 itr->bci()); break;
1562 case Bytecodes::_putstatic: do_field(false, true, itr->get_index_u2_cpcache(), itr->bci()); break;
1563 case Bytecodes::_getfield: do_field(true, false, itr->get_index_u2_cpcache(), itr->bci()); break;
1564 case Bytecodes::_putfield: do_field(false, false, itr->get_index_u2_cpcache(), itr->bci()); break;
1565
1566 case Bytecodes::_invokevirtual:
1567 case Bytecodes::_invokespecial: do_method(false, false, itr->get_index_u2_cpcache(), itr->bci()); break;
1568 case Bytecodes::_invokestatic: do_method(true, false, itr->get_index_u2_cpcache(), itr->bci()); break;
1569 case Bytecodes::_invokedynamic: do_method(true, false, itr->get_index_u4(), itr->bci()); break;
1570 case Bytecodes::_invokeinterface: do_method(false, true, itr->get_index_u2_cpcache(), itr->bci()); break;
1571 case Bytecodes::_newarray:
1572 case Bytecodes::_anewarray: pp_new_ref(vCTS, itr->bci()); break;
1573 case Bytecodes::_checkcast: do_checkcast(); break;
1574 case Bytecodes::_arraylength:
1575 case Bytecodes::_instanceof: pp(rCTS, vCTS); break;
1576 case Bytecodes::_monitorenter: do_monitorenter(itr->bci()); break;
1577 case Bytecodes::_monitorexit: do_monitorexit(itr->bci()); break;
1578
1579 case Bytecodes::_athrow: // handled by do_exception_edge() BUT ...
1580 // vlh(apple): do_exception_edge() does not get
1581 // called if method has no exception handlers
1582 if ((!_has_exceptions) && (_monitor_top > 0)) {
1583 _monitor_safe = false;
1584 }
1585 break;
1586
1587 case Bytecodes::_areturn: do_return_monitor_check();
1588 ppop1(refCTS);
1589 break;
1590 case Bytecodes::_ifnull:
1591 case Bytecodes::_ifnonnull: ppop1(refCTS); break;
1592 case Bytecodes::_multianewarray: do_multianewarray(*(itr->bcp()+3), itr->bci()); break;
1593
1594 case Bytecodes::_wide: fatal("Iterator should skip this bytecode"); break;
1595 case Bytecodes::_ret: break;
1596
1597 // Java opcodes
1598 case Bytecodes::_lookupswitch: ppop1(valCTS); break;
1599
1600 default:
1601 tty->print("unexpected opcode: %d\n", itr->code());
1602 ShouldNotReachHere();
1603 break;
1604 }
1605 }
1606
1607 void GenerateOopMap::check_type(CellTypeState expected, CellTypeState actual) {
1608 if (!expected.equal_kind(actual)) {
1609 verify_error("wrong type on stack (found: %c expected: %c)", actual.to_char(), expected.to_char());
1610 }
1611 }
1612
1613 void GenerateOopMap::ppstore(CellTypeState *in, int loc_no) {
1614 while(!(*in).is_bottom()) {
1615 CellTypeState expected =*in++;
1616 CellTypeState actual = pop();
1617 check_type(expected, actual);
1618 assert(loc_no >= 0, "sanity check");
1619 set_var(loc_no++, actual);
1620 }
1621 }
1622
1623 void GenerateOopMap::ppload(CellTypeState *out, int loc_no) {
1624 while(!(*out).is_bottom()) {
1625 CellTypeState out1 = *out++;
1626 CellTypeState vcts = get_var(loc_no);
1627 assert(out1.can_be_reference() || out1.can_be_value(),
1628 "can only load refs. and values.");
1629 if (out1.is_reference()) {
1630 assert(loc_no>=0, "sanity check");
1631 if (!vcts.is_reference()) {
1632 // We were asked to push a reference, but the type of the
1633 // variable can be something else
1634 _conflict = true;
1635 if (vcts.can_be_uninit()) {
1636 // It is a ref-uninit conflict (at least). If there are other
1637 // problems, we'll get them in the next round
1638 add_to_ref_init_set(loc_no);
1639 vcts = out1;
1640 } else {
1641 // It wasn't a ref-uninit conflict. So must be a
1642 // ref-val or ref-pc conflict. Split the variable.
1643 record_refval_conflict(loc_no);
1644 vcts = out1;
1645 }
1646 push(out1); // recover...
1647 } else {
1648 push(vcts); // preserve reference.
1649 }
1650 // Otherwise it is a conflict, but one that verification would
1651 // have caught if illegal. In particular, it can't be a topCTS
1652 // resulting from mergeing two difference pcCTS's since the verifier
1653 // would have rejected any use of such a merge.
1654 } else {
1655 push(out1); // handle val/init conflict
1656 }
1657 loc_no++;
1658 }
1659 }
1660
1661 void GenerateOopMap::ppdupswap(int poplen, const char *out) {
1662 CellTypeState actual[5];
1663 assert(poplen < 5, "this must be less than length of actual vector");
1664
1665 // pop all arguments
1666 for(int i = 0; i < poplen; i++) actual[i] = pop();
1667
1668 // put them back
1669 char push_ch = *out++;
1670 while (push_ch != '\0') {
1671 int idx = push_ch - '1';
1672 assert(idx >= 0 && idx < poplen, "wrong arguments");
1673 push(actual[idx]);
1674 push_ch = *out++;
1675 }
1676 }
1677
1678 void GenerateOopMap::ppop1(CellTypeState out) {
1679 CellTypeState actual = pop();
1680 check_type(out, actual);
1681 }
1682
1683 void GenerateOopMap::ppop(CellTypeState *out) {
1684 while (!(*out).is_bottom()) {
1685 ppop1(*out++);
1686 }
1687 }
1688
1689 void GenerateOopMap::ppush1(CellTypeState in) {
1690 assert(in.is_reference() | in.is_value(), "sanity check");
1691 push(in);
1692 }
1693
1694 void GenerateOopMap::ppush(CellTypeState *in) {
1695 while (!(*in).is_bottom()) {
1696 ppush1(*in++);
1697 }
1698 }
1699
1700 void GenerateOopMap::pp(CellTypeState *in, CellTypeState *out) {
1701 ppop(in);
1702 ppush(out);
1703 }
1704
1705 void GenerateOopMap::pp_new_ref(CellTypeState *in, int bci) {
1706 ppop(in);
1707 ppush1(CellTypeState::make_line_ref(bci));
1708 }
1709
1710 void GenerateOopMap::ppop_any(int poplen) {
1711 if (_stack_top >= poplen) {
1712 _stack_top -= poplen;
1713 } else {
1714 verify_error("stack underflow");
1715 }
1716 }
1717
1718 // Replace all occurences of the state 'match' with the state 'replace'
1719 // in our current state vector.
1720 void GenerateOopMap::replace_all_CTS_matches(CellTypeState match,
1721 CellTypeState replace) {
1722 int i;
1723 int len = _max_locals + _stack_top;
1724 bool change = false;
1725
1726 for (i = len - 1; i >= 0; i--) {
1727 if (match.equal(_state[i])) {
1728 _state[i] = replace;
1729 }
1730 }
1731
1732 if (_monitor_top > 0) {
1733 int base = _max_locals + _max_stack;
1734 len = base + _monitor_top;
1735 for (i = len - 1; i >= base; i--) {
1736 if (match.equal(_state[i])) {
1737 _state[i] = replace;
1738 }
1739 }
1740 }
1741 }
1742
1743 void GenerateOopMap::do_checkcast() {
1744 CellTypeState actual = pop();
1745 check_type(refCTS, actual);
1746 push(actual);
1747 }
1748
1749 void GenerateOopMap::do_monitorenter(int bci) {
1750 CellTypeState actual = pop();
1751 if (_monitor_top == bad_monitors) {
1752 return;
1753 }
1754
1755 // Bail out when we get repeated locks on an identical monitor. This case
1756 // isn't too hard to handle and can be made to work if supporting nested
1757 // redundant synchronized statements becomes a priority.
1758 //
1759 // See also "Note" in do_monitorexit(), below.
1760 if (actual.is_lock_reference()) {
1761 _monitor_top = bad_monitors;
1762 _monitor_safe = false;
1763
1764 if (TraceMonitorMismatch) {
1765 report_monitor_mismatch("nested redundant lock -- bailout...");
1766 }
1767 return;
1768 }
1769
1770 CellTypeState lock = CellTypeState::make_lock_ref(bci);
1771 check_type(refCTS, actual);
1772 if (!actual.is_info_top()) {
1773 replace_all_CTS_matches(actual, lock);
1774 monitor_push(lock);
1775 }
1776 }
1777
1778 void GenerateOopMap::do_monitorexit(int bci) {
1779 CellTypeState actual = pop();
1780 if (_monitor_top == bad_monitors) {
1781 return;
1782 }
1783 check_type(refCTS, actual);
1784 CellTypeState expected = monitor_pop();
1785 if (!actual.is_lock_reference() || !expected.equal(actual)) {
1786 // The monitor we are exiting is not verifiably the one
1787 // on the top of our monitor stack. This causes a monitor
1788 // mismatch.
1789 _monitor_top = bad_monitors;
1790 _monitor_safe = false;
1791
1792 // We need to mark this basic block as changed so that
1793 // this monitorexit will be visited again. We need to
1794 // do this to ensure that we have accounted for the
1795 // possibility that this bytecode will throw an
1796 // exception.
1797 BasicBlock* bb = get_basic_block_containing(bci);
1798 bb->set_changed(true);
1799 bb->_monitor_top = bad_monitors;
1800
1801 if (TraceMonitorMismatch) {
1802 report_monitor_mismatch("improper monitor pair");
1803 }
1804 } else {
1805 // This code is a fix for the case where we have repeated
1806 // locking of the same object in straightline code. We clear
1807 // out the lock when it is popped from the monitor stack
1808 // and replace it with an unobtrusive reference value that can
1809 // be locked again.
1810 //
1811 // Note: when generateOopMap is fixed to properly handle repeated,
1812 // nested, redundant locks on the same object, then this
1813 // fix will need to be removed at that time.
1814 replace_all_CTS_matches(actual, CellTypeState::make_line_ref(bci));
1815 }
1816 }
1817
1818 void GenerateOopMap::do_return_monitor_check() {
1819 if (_monitor_top > 0) {
1820 // The monitor stack must be empty when we leave the method
1821 // for the monitors to be properly matched.
1822 _monitor_safe = false;
1823
1824 // Since there are no successors to the *return bytecode, it
1825 // isn't necessary to set _monitor_top to bad_monitors.
1826
1827 if (TraceMonitorMismatch) {
1828 report_monitor_mismatch("non-empty monitor stack at return");
1829 }
1830 }
1831 }
1832
1833 void GenerateOopMap::do_jsr(int targ_bci) {
1834 push(CellTypeState::make_addr(targ_bci));
1835 }
1836
1837
1838
1839 void GenerateOopMap::do_ldc(int idx, int bci) {
1840 constantPoolOop cp = method()->constants();
1841 CellTypeState cts = cp->is_pointer_entry(idx) ? CellTypeState::make_line_ref(bci) : valCTS;
1842 ppush1(cts);
1843 }
1844
1845 void GenerateOopMap::do_multianewarray(int dims, int bci) {
1846 assert(dims >= 1, "sanity check");
1847 for(int i = dims -1; i >=0; i--) {
1848 ppop1(valCTS);
1849 }
1850 ppush1(CellTypeState::make_line_ref(bci));
1851 }
1852
1853 void GenerateOopMap::do_astore(int idx) {
1854 CellTypeState r_or_p = pop();
1855 if (!r_or_p.is_address() && !r_or_p.is_reference()) {
1856 // We actually expected ref or pc, but we only report that we expected a ref. It does not
1857 // really matter (at least for now)
1858 verify_error("wrong type on stack (found: %c, expected: {pr})", r_or_p.to_char());
1859 return;
1860 }
1861 set_var(idx, r_or_p);
1862 }
1863
1864 // Copies bottom/zero terminated CTS string from "src" into "dst".
1865 // Does NOT terminate with a bottom. Returns the number of cells copied.
1866 int GenerateOopMap::copy_cts(CellTypeState *dst, CellTypeState *src) {
1867 int idx = 0;
1868 while (!src[idx].is_bottom()) {
1869 dst[idx] = src[idx];
1870 idx++;
1871 }
1872 return idx;
1873 }
1874
1875 void GenerateOopMap::do_field(int is_get, int is_static, int idx, int bci) {
1876 // Dig up signature for field in constant pool
1877 constantPoolOop cp = method()->constants();
1878 int nameAndTypeIdx = cp->name_and_type_ref_index_at(idx);
1879 int signatureIdx = cp->signature_ref_index_at(nameAndTypeIdx);
1880 symbolOop signature = cp->symbol_at(signatureIdx);
1881
1882 // Parse signature (espcially simple for fields)
1883 assert(signature->utf8_length() > 0, "field signatures cannot have zero length");
1884 // The signature is UFT8 encoded, but the first char is always ASCII for signatures.
1885 char sigch = (char)*(signature->base());
1886 CellTypeState temp[4];
1887 CellTypeState *eff = sigchar_to_effect(sigch, bci, temp);
1888
1889 CellTypeState in[4];
1890 CellTypeState *out;
1891 int i = 0;
1892
1893 if (is_get) {
1894 out = eff;
1895 } else {
1896 out = epsilonCTS;
1897 i = copy_cts(in, eff);
1898 }
1899 if (!is_static) in[i++] = CellTypeState::ref;
1900 in[i] = CellTypeState::bottom;
1901 assert(i<=3, "sanity check");
1902 pp(in, out);
1903 }
1904
1905 void GenerateOopMap::do_method(int is_static, int is_interface, int idx, int bci) {
1906 // Dig up signature for field in constant pool
1907 constantPoolOop cp = _method->constants();
1908 symbolOop signature = cp->signature_ref_at(idx);
1909
1910 // Parse method signature
1911 CellTypeState out[4];
1912 CellTypeState in[MAXARGSIZE+1]; // Includes result
1913 ComputeCallStack cse(signature);
1914
1915 // Compute return type
1916 int res_length= cse.compute_for_returntype(out);
1917
1918 // Temporary hack.
1919 if (out[0].equal(CellTypeState::ref) && out[1].equal(CellTypeState::bottom)) {
1920 out[0] = CellTypeState::make_line_ref(bci);
1921 }
1922
1923 assert(res_length<=4, "max value should be vv");
1924
1925 // Compute arguments
1926 int arg_length = cse.compute_for_parameters(is_static != 0, in);
1927 assert(arg_length<=MAXARGSIZE, "too many locals");
1928
1929 // Pop arguments
1930 for (int i = arg_length - 1; i >= 0; i--) ppop1(in[i]);// Do args in reverse order.
1931
1932 // Report results
1933 if (_report_result_for_send == true) {
1934 fill_stackmap_for_opcodes(_itr_send, vars(), stack(), _stack_top);
1935 _report_result_for_send = false;
1936 }
1937
1938 // Push return address
1939 ppush(out);
1940 }
1941
1942 // This is used to parse the signature for fields, since they are very simple...
1943 CellTypeState *GenerateOopMap::sigchar_to_effect(char sigch, int bci, CellTypeState *out) {
1944 // Object and array
1945 if (sigch=='L' || sigch=='[') {
1946 out[0] = CellTypeState::make_line_ref(bci);
1947 out[1] = CellTypeState::bottom;
1948 return out;
1949 }
1950 if (sigch == 'J' || sigch == 'D' ) return vvCTS; // Long and Double
1951 if (sigch == 'V' ) return epsilonCTS; // Void
1952 return vCTS; // Otherwise
1953 }
1954
1955 long GenerateOopMap::_total_byte_count = 0;
1956 elapsedTimer GenerateOopMap::_total_oopmap_time;
1957
1958 // This function assumes "bcs" is at a "ret" instruction and that the vars
1959 // state is valid for that instruction. Furthermore, the ret instruction
1960 // must be the last instruction in "bb" (we store information about the
1961 // "ret" in "bb").
1962 void GenerateOopMap::ret_jump_targets_do(BytecodeStream *bcs, jmpFct_t jmpFct, int varNo, int *data) {
1963 CellTypeState ra = vars()[varNo];
1964 if (!ra.is_good_address()) {
1965 verify_error("ret returns from two jsr subroutines?");
1966 return;
1967 }
1968 int target = ra.get_info();
1969
1970 RetTableEntry* rtEnt = _rt.find_jsrs_for_target(target);
1971 int bci = bcs->bci();
1972 for (int i = 0; i < rtEnt->nof_jsrs(); i++) {
1973 int target_bci = rtEnt->jsrs(i);
1974 // Make sure a jrtRet does not set the changed bit for dead basicblock.
1975 BasicBlock* jsr_bb = get_basic_block_containing(target_bci - 1);
1976 debug_only(BasicBlock* target_bb = &jsr_bb[1];)
1977 assert(target_bb == get_basic_block_at(target_bci), "wrong calc. of successor basicblock");
1978 bool alive = jsr_bb->is_alive();
1979 if (TraceNewOopMapGeneration) {
1980 tty->print("pc = %d, ret -> %d alive: %s\n", bci, target_bci, alive ? "true" : "false");
1981 }
1982 if (alive) jmpFct(this, target_bci, data);
1983 }
1984 }
1985
1986 //
1987 // Debug method
1988 //
1989 char* GenerateOopMap::state_vec_to_string(CellTypeState* vec, int len) {
1990 #ifdef ASSERT
1991 int checklen = MAX3(_max_locals, _max_stack, _max_monitors) + 1;
1992 assert(len < checklen, "state_vec_buf overflow");
1993 #endif
1994 for (int i = 0; i < len; i++) _state_vec_buf[i] = vec[i].to_char();
1995 _state_vec_buf[len] = 0;
1996 return _state_vec_buf;
1997 }
1998
1999 void GenerateOopMap::print_time() {
2000 tty->print_cr ("Accumulated oopmap times:");
2001 tty->print_cr ("---------------------------");
2002 tty->print_cr (" Total : %3.3f sec.", GenerateOopMap::_total_oopmap_time.seconds());
2003 tty->print_cr (" (%3.0f bytecodes per sec) ",
2004 GenerateOopMap::_total_byte_count / GenerateOopMap::_total_oopmap_time.seconds());
2005 }
2006
2007 //
2008 // ============ Main Entry Point ===========
2009 //
2010 GenerateOopMap::GenerateOopMap(methodHandle method) {
2011 // We have to initialize all variables here, that can be queried directly
2012 _method = method;
2013 _max_locals=0;
2014 _init_vars = NULL;
2015
2016 #ifndef PRODUCT
2017 // If we are doing a detailed trace, include the regular trace information.
2018 if (TraceNewOopMapGenerationDetailed) {
2019 TraceNewOopMapGeneration = true;
2020 }
2021 #endif
2022 }
2023
2024 void GenerateOopMap::compute_map(TRAPS) {
2025 #ifndef PRODUCT
2026 if (TimeOopMap2) {
2027 method()->print_short_name(tty);
2028 tty->print(" ");
2029 }
2030 if (TimeOopMap) {
2031 _total_byte_count += method()->code_size();
2032 }
2033 #endif
2034 TraceTime t_single("oopmap time", TimeOopMap2);
2035 TraceTime t_all(NULL, &_total_oopmap_time, TimeOopMap);
2036
2037 // Initialize values
2038 _got_error = false;
2039 _conflict = false;
2040 _max_locals = method()->max_locals();
2041 _max_stack = method()->max_stack();
2042 _has_exceptions = (method()->exception_table()->length() > 0);
2043 _nof_refval_conflicts = 0;
2044 _init_vars = new GrowableArray<intptr_t>(5); // There are seldom more than 5 init_vars
2045 _report_result = false;
2046 _report_result_for_send = false;
2047 _new_var_map = NULL;
2048 _ret_adr_tos = new GrowableArray<intptr_t>(5); // 5 seems like a good number;
2049 _did_rewriting = false;
2050 _did_relocation = false;
2051
2052 if (TraceNewOopMapGeneration) {
2053 tty->print("Method name: %s\n", method()->name()->as_C_string());
2054 if (Verbose) {
2055 _method->print_codes();
2056 tty->print_cr("Exception table:");
2057 typeArrayOop excps = method()->exception_table();
2058 for(int i = 0; i < excps->length(); i += 4) {
2059 tty->print_cr("[%d - %d] -> %d", excps->int_at(i + 0), excps->int_at(i + 1), excps->int_at(i + 2));
2060 }
2061 }
2062 }
2063
2064 // if no code - do nothing
2065 // compiler needs info
2066 if (method()->code_size() == 0 || _max_locals + method()->max_stack() == 0) {
2067 fill_stackmap_prolog(0);
2068 fill_stackmap_epilog();
2069 return;
2070 }
2071 // Step 1: Compute all jump targets and their return value
2072 if (!_got_error)
2073 _rt.compute_ret_table(_method);
2074
2075 // Step 2: Find all basic blocks and count GC points
2076 if (!_got_error)
2077 mark_bbheaders_and_count_gc_points();
2078
2079 // Step 3: Calculate stack maps
2080 if (!_got_error)
2081 do_interpretation();
2082
2083 // Step 4:Return results
2084 if (!_got_error && report_results())
2085 report_result();
2086
2087 if (_got_error) {
2088 THROW_HANDLE(_exception);
2089 }
2090 }
2091
2092 // Error handling methods
2093 // These methods create an exception for the current thread which is thrown
2094 // at the bottom of the call stack, when it returns to compute_map(). The
2095 // _got_error flag controls execution. NOT TODO: The VM exception propagation
2096 // mechanism using TRAPS/CHECKs could be used here instead but it would need
2097 // to be added as a parameter to every function and checked for every call.
2098 // The tons of extra code it would generate didn't seem worth the change.
2099 //
2100 void GenerateOopMap::error_work(const char *format, va_list ap) {
2101 _got_error = true;
2102 char msg_buffer[512];
2103 vsnprintf(msg_buffer, sizeof(msg_buffer), format, ap);
2104 // Append method name
2105 char msg_buffer2[512];
2106 jio_snprintf(msg_buffer2, sizeof(msg_buffer2), "%s in method %s", msg_buffer, method()->name()->as_C_string());
2107 _exception = Exceptions::new_exception(Thread::current(),
2108 vmSymbols::java_lang_LinkageError(), msg_buffer2);
2109 }
2110
2111 void GenerateOopMap::report_error(const char *format, ...) {
2112 va_list ap;
2113 va_start(ap, format);
2114 error_work(format, ap);
2115 }
2116
2117 void GenerateOopMap::verify_error(const char *format, ...) {
2118 // We do not distinguish between different types of errors for verification
2119 // errors. Let the verifier give a better message.
2120 const char *msg = "Illegal class file encountered. Try running with -Xverify:all";
2121 _got_error = true;
2122 // Append method name
2123 char msg_buffer2[512];
2124 jio_snprintf(msg_buffer2, sizeof(msg_buffer2), "%s in method %s", msg,
2125 method()->name()->as_C_string());
2126 _exception = Exceptions::new_exception(Thread::current(),
2127 vmSymbols::java_lang_LinkageError(), msg_buffer2);
2128 }
2129
2130 //
2131 // Report result opcodes
2132 //
2133 void GenerateOopMap::report_result() {
2134
2135 if (TraceNewOopMapGeneration) tty->print_cr("Report result pass");
2136
2137 // We now want to report the result of the parse
2138 _report_result = true;
2139
2140 // Prolog code
2141 fill_stackmap_prolog(_gc_points);
2142
2143 // Mark everything changed, then do one interpretation pass.
2144 for (int i = 0; i<_bb_count; i++) {
2145 if (_basic_blocks[i].is_reachable()) {
2146 _basic_blocks[i].set_changed(true);
2147 interp_bb(&_basic_blocks[i]);
2148 }
2149 }
2150
2151 // Note: Since we are skipping dead-code when we are reporting results, then
2152 // the no. of encountered gc-points might be fewer than the previously number
2153 // we have counted. (dead-code is a pain - it should be removed before we get here)
2154 fill_stackmap_epilog();
2155
2156 // Report initvars
2157 fill_init_vars(_init_vars);
2158
2159 _report_result = false;
2160 }
2161
2162 void GenerateOopMap::result_for_basicblock(int bci) {
2163 if (TraceNewOopMapGeneration) tty->print_cr("Report result pass for basicblock");
2164
2165 // We now want to report the result of the parse
2166 _report_result = true;
2167
2168 // Find basicblock and report results
2169 BasicBlock* bb = get_basic_block_containing(bci);
2170 assert(bb->is_reachable(), "getting result from unreachable basicblock");
2171 bb->set_changed(true);
2172 interp_bb(bb);
2173 }
2174
2175 //
2176 // Conflict handling code
2177 //
2178
2179 void GenerateOopMap::record_refval_conflict(int varNo) {
2180 assert(varNo>=0 && varNo< _max_locals, "index out of range");
2181
2182 if (TraceOopMapRewrites) {
2183 tty->print("### Conflict detected (local no: %d)\n", varNo);
2184 }
2185
2186 if (!_new_var_map) {
2187 _new_var_map = NEW_RESOURCE_ARRAY(int, _max_locals);
2188 for (int k = 0; k < _max_locals; k++) _new_var_map[k] = k;
2189 }
2190
2191 if ( _new_var_map[varNo] == varNo) {
2192 // Check if max. number of locals has been reached
2193 if (_max_locals + _nof_refval_conflicts >= MAX_LOCAL_VARS) {
2194 report_error("Rewriting exceeded local variable limit");
2195 return;
2196 }
2197 _new_var_map[varNo] = _max_locals + _nof_refval_conflicts;
2198 _nof_refval_conflicts++;
2199 }
2200 }
2201
2202 void GenerateOopMap::rewrite_refval_conflicts()
2203 {
2204 // We can get here two ways: Either a rewrite conflict was detected, or
2205 // an uninitialize reference was detected. In the second case, we do not
2206 // do any rewriting, we just want to recompute the reference set with the
2207 // new information
2208
2209 int nof_conflicts = 0; // Used for debugging only
2210
2211 if ( _nof_refval_conflicts == 0 )
2212 return;
2213
2214 // Check if rewrites are allowed in this parse.
2215 if (!allow_rewrites() && !IgnoreRewrites) {
2216 fatal("Rewriting method not allowed at this stage");
2217 }
2218
2219
2220 // This following flag is to tempoary supress rewrites. The locals that might conflict will
2221 // all be set to contain values. This is UNSAFE - however, until the rewriting has been completely
2222 // tested it is nice to have.
2223 if (IgnoreRewrites) {
2224 if (Verbose) {
2225 tty->print("rewrites suppressed for local no. ");
2226 for (int l = 0; l < _max_locals; l++) {
2227 if (_new_var_map[l] != l) {
2228 tty->print("%d ", l);
2229 vars()[l] = CellTypeState::value;
2230 }
2231 }
2232 tty->cr();
2233 }
2234
2235 // That was that...
2236 _new_var_map = NULL;
2237 _nof_refval_conflicts = 0;
2238 _conflict = false;
2239
2240 return;
2241 }
2242
2243 // Tracing flag
2244 _did_rewriting = true;
2245
2246 if (TraceOopMapRewrites) {
2247 tty->print_cr("ref/value conflict for method %s - bytecodes are getting rewritten", method()->name()->as_C_string());
2248 method()->print();
2249 method()->print_codes();
2250 }
2251
2252 assert(_new_var_map!=NULL, "nothing to rewrite");
2253 assert(_conflict==true, "We should not be here");
2254
2255 compute_ret_adr_at_TOS();
2256 if (!_got_error) {
2257 for (int k = 0; k < _max_locals && !_got_error; k++) {
2258 if (_new_var_map[k] != k) {
2259 if (TraceOopMapRewrites) {
2260 tty->print_cr("Rewriting: %d -> %d", k, _new_var_map[k]);
2261 }
2262 rewrite_refval_conflict(k, _new_var_map[k]);
2263 if (_got_error) return;
2264 nof_conflicts++;
2265 }
2266 }
2267 }
2268
2269 assert(nof_conflicts == _nof_refval_conflicts, "sanity check");
2270
2271 // Adjust the number of locals
2272 method()->set_max_locals(_max_locals+_nof_refval_conflicts);
2273 _max_locals += _nof_refval_conflicts;
2274
2275 // That was that...
2276 _new_var_map = NULL;
2277 _nof_refval_conflicts = 0;
2278 }
2279
2280 void GenerateOopMap::rewrite_refval_conflict(int from, int to) {
2281 bool startOver;
2282 do {
2283 // Make sure that the BytecodeStream is constructed in the loop, since
2284 // during rewriting a new method oop is going to be used, and the next time
2285 // around we want to use that.
2286 BytecodeStream bcs(_method);
2287 startOver = false;
2288
2289 while( bcs.next() >=0 && !startOver && !_got_error) {
2290 startOver = rewrite_refval_conflict_inst(&bcs, from, to);
2291 }
2292 } while (startOver && !_got_error);
2293 }
2294
2295 /* If the current instruction is one that uses local variable "from"
2296 in a ref way, change it to use "to". There's a subtle reason why we
2297 renumber the ref uses and not the non-ref uses: non-ref uses may be
2298 2 slots wide (double, long) which would necessitate keeping track of
2299 whether we should add one or two variables to the method. If the change
2300 affected the width of some instruction, returns "TRUE"; otherwise, returns "FALSE".
2301 Another reason for moving ref's value is for solving (addr, ref) conflicts, which
2302 both uses aload/astore methods.
2303 */
2304 bool GenerateOopMap::rewrite_refval_conflict_inst(BytecodeStream *itr, int from, int to) {
2305 Bytecodes::Code bc = itr->code();
2306 int index;
2307 int bci = itr->bci();
2308
2309 if (is_aload(itr, &index) && index == from) {
2310 if (TraceOopMapRewrites) {
2311 tty->print_cr("Rewriting aload at bci: %d", bci);
2312 }
2313 return rewrite_load_or_store(itr, Bytecodes::_aload, Bytecodes::_aload_0, to);
2314 }
2315
2316 if (is_astore(itr, &index) && index == from) {
2317 if (!stack_top_holds_ret_addr(bci)) {
2318 if (TraceOopMapRewrites) {
2319 tty->print_cr("Rewriting astore at bci: %d", bci);
2320 }
2321 return rewrite_load_or_store(itr, Bytecodes::_astore, Bytecodes::_astore_0, to);
2322 } else {
2323 if (TraceOopMapRewrites) {
2324 tty->print_cr("Supress rewriting of astore at bci: %d", bci);
2325 }
2326 }
2327 }
2328
2329 return false;
2330 }
2331
2332 // The argument to this method is:
2333 // bc : Current bytecode
2334 // bcN : either _aload or _astore
2335 // bc0 : either _aload_0 or _astore_0
2336 bool GenerateOopMap::rewrite_load_or_store(BytecodeStream *bcs, Bytecodes::Code bcN, Bytecodes::Code bc0, unsigned int varNo) {
2337 assert(bcN == Bytecodes::_astore || bcN == Bytecodes::_aload, "wrong argument (bcN)");
2338 assert(bc0 == Bytecodes::_astore_0 || bc0 == Bytecodes::_aload_0, "wrong argument (bc0)");
2339 int ilen = Bytecodes::length_at(bcs->bcp());
2340 int newIlen;
2341
2342 if (ilen == 4) {
2343 // Original instruction was wide; keep it wide for simplicity
2344 newIlen = 4;
2345 } else if (varNo < 4)
2346 newIlen = 1;
2347 else if (varNo >= 256)
2348 newIlen = 4;
2349 else
2350 newIlen = 2;
2351
2352 // If we need to relocate in order to patch the byte, we
2353 // do the patching in a temp. buffer, that is passed to the reloc.
2354 // The patching of the bytecode stream is then done by the Relocator.
2355 // This is neccesary, since relocating the instruction at a certain bci, might
2356 // also relocate that instruction, e.g., if a _goto before it gets widen to a _goto_w.
2357 // Hence, we do not know which bci to patch after relocation.
2358
2359 assert(newIlen <= 4, "sanity check");
2360 u_char inst_buffer[4]; // Max. instruction size is 4.
2361 address bcp;
2362
2363 if (newIlen != ilen) {
2364 // Relocation needed do patching in temp. buffer
2365 bcp = (address)inst_buffer;
2366 } else {
2367 bcp = _method->bcp_from(bcs->bci());
2368 }
2369
2370 // Patch either directly in methodOop or in temp. buffer
2371 if (newIlen == 1) {
2372 assert(varNo < 4, "varNo too large");
2373 *bcp = bc0 + varNo;
2374 } else if (newIlen == 2) {
2375 assert(varNo < 256, "2-byte index needed!");
2376 *(bcp + 0) = bcN;
2377 *(bcp + 1) = varNo;
2378 } else {
2379 assert(newIlen == 4, "Wrong instruction length");
2380 *(bcp + 0) = Bytecodes::_wide;
2381 *(bcp + 1) = bcN;
2382 Bytes::put_Java_u2(bcp+2, varNo);
2383 }
2384
2385 if (newIlen != ilen) {
2386 expand_current_instr(bcs->bci(), ilen, newIlen, inst_buffer);
2387 }
2388
2389
2390 return (newIlen != ilen);
2391 }
2392
2393 class RelocCallback : public RelocatorListener {
2394 private:
2395 GenerateOopMap* _gom;
2396 public:
2397 RelocCallback(GenerateOopMap* gom) { _gom = gom; };
2398
2399 // Callback method
2400 virtual void relocated(int bci, int delta, int new_code_length) {
2401 _gom->update_basic_blocks (bci, delta, new_code_length);
2402 _gom->update_ret_adr_at_TOS(bci, delta);
2403 _gom->_rt.update_ret_table (bci, delta);
2404 }
2405 };
2406
2407 // Returns true if expanding was succesful. Otherwise, reports an error and
2408 // returns false.
2409 void GenerateOopMap::expand_current_instr(int bci, int ilen, int newIlen, u_char inst_buffer[]) {
2410 Thread *THREAD = Thread::current(); // Could really have TRAPS argument.
2411 RelocCallback rcb(this);
2412 Relocator rc(_method, &rcb);
2413 methodHandle m= rc.insert_space_at(bci, newIlen, inst_buffer, THREAD);
2414 if (m.is_null() || HAS_PENDING_EXCEPTION) {
2415 report_error("could not rewrite method - exception occurred or bytecode buffer overflow");
2416 return;
2417 }
2418
2419 // Relocator returns a new method oop.
2420 _did_relocation = true;
2421 _method = m;
2422 }
2423
2424
2425 bool GenerateOopMap::is_astore(BytecodeStream *itr, int *index) {
2426 Bytecodes::Code bc = itr->code();
2427 switch(bc) {
2428 case Bytecodes::_astore_0:
2429 case Bytecodes::_astore_1:
2430 case Bytecodes::_astore_2:
2431 case Bytecodes::_astore_3:
2432 *index = bc - Bytecodes::_astore_0;
2433 return true;
2434 case Bytecodes::_astore:
2435 *index = itr->get_index();
2436 return true;
2437 }
2438 return false;
2439 }
2440
2441 bool GenerateOopMap::is_aload(BytecodeStream *itr, int *index) {
2442 Bytecodes::Code bc = itr->code();
2443 switch(bc) {
2444 case Bytecodes::_aload_0:
2445 case Bytecodes::_aload_1:
2446 case Bytecodes::_aload_2:
2447 case Bytecodes::_aload_3:
2448 *index = bc - Bytecodes::_aload_0;
2449 return true;
2450
2451 case Bytecodes::_aload:
2452 *index = itr->get_index();
2453 return true;
2454 }
2455 return false;
2456 }
2457
2458
2459 // Return true iff the top of the operand stack holds a return address at
2460 // the current instruction
2461 bool GenerateOopMap::stack_top_holds_ret_addr(int bci) {
2462 for(int i = 0; i < _ret_adr_tos->length(); i++) {
2463 if (_ret_adr_tos->at(i) == bci)
2464 return true;
2465 }
2466
2467 return false;
2468 }
2469
2470 void GenerateOopMap::compute_ret_adr_at_TOS() {
2471 assert(_ret_adr_tos != NULL, "must be initialized");
2472 _ret_adr_tos->clear();
2473
2474 for (int i = 0; i < bb_count(); i++) {
2475 BasicBlock* bb = &_basic_blocks[i];
2476
2477 // Make sure to only check basicblocks that are reachable
2478 if (bb->is_reachable()) {
2479
2480 // For each Basic block we check all instructions
2481 BytecodeStream bcs(_method);
2482 bcs.set_interval(bb->_bci, next_bb_start_pc(bb));
2483
2484 restore_state(bb);
2485
2486 while (bcs.next()>=0 && !_got_error) {
2487 // TDT: should this be is_good_address() ?
2488 if (_stack_top > 0 && stack()[_stack_top-1].is_address()) {
2489 _ret_adr_tos->append(bcs.bci());
2490 if (TraceNewOopMapGeneration) {
2491 tty->print_cr("Ret_adr TOS at bci: %d", bcs.bci());
2492 }
2493 }
2494 interp1(&bcs);
2495 }
2496 }
2497 }
2498 }
2499
2500 void GenerateOopMap::update_ret_adr_at_TOS(int bci, int delta) {
2501 for(int i = 0; i < _ret_adr_tos->length(); i++) {
2502 int v = _ret_adr_tos->at(i);
2503 if (v > bci) _ret_adr_tos->at_put(i, v + delta);
2504 }
2505 }
2506
2507 // ===================================================================
2508
2509 #ifndef PRODUCT
2510 int ResolveOopMapConflicts::_nof_invocations = 0;
2511 int ResolveOopMapConflicts::_nof_rewrites = 0;
2512 int ResolveOopMapConflicts::_nof_relocations = 0;
2513 #endif
2514
2515 methodHandle ResolveOopMapConflicts::do_potential_rewrite(TRAPS) {
2516 compute_map(CHECK_(methodHandle()));
2517
2518 #ifndef PRODUCT
2519 // Tracking and statistics
2520 if (PrintRewrites) {
2521 _nof_invocations++;
2522 if (did_rewriting()) {
2523 _nof_rewrites++;
2524 if (did_relocation()) _nof_relocations++;
2525 tty->print("Method was rewritten %s: ", (did_relocation()) ? "and relocated" : "");
2526 method()->print_value(); tty->cr();
2527 tty->print_cr("Cand.: %d rewrts: %d (%d%%) reloc.: %d (%d%%)",
2528 _nof_invocations,
2529 _nof_rewrites, (_nof_rewrites * 100) / _nof_invocations,
2530 _nof_relocations, (_nof_relocations * 100) / _nof_invocations);
2531 }
2532 }
2533 #endif
2534 return methodHandle(THREAD, method());
2535 }