generateOopMap.cpp 82.2 KB
Newer Older
D
duke 已提交
1
/*
J
Merge  
jrose 已提交
2
 * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
D
duke 已提交
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
19 20 21
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
D
duke 已提交
22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372
 *
 */

//
//
// Compute stack layouts for each instruction in method.
//
//  Problems:
//  - What to do about jsr with different types of local vars?
//  Need maps that are conditional on jsr path?
//  - Jsr and exceptions should be done more efficiently (the retAddr stuff)
//
//  Alternative:
//  - Could extend verifier to provide this information.
//    For: one fewer abstract interpreter to maintain. Against: the verifier
//    solves a bigger problem so slower (undesirable to force verification of
//    everything?).
//
//  Algorithm:
//    Partition bytecodes into basic blocks
//    For each basic block: store entry state (vars, stack). For instructions
//    inside basic blocks we do not store any state (instead we recompute it
//    from state produced by previous instruction).
//
//    Perform abstract interpretation of bytecodes over this lattice:
//
//                _--'#'--_
//               /  /  \   \
//             /   /     \   \
//            /    |     |     \
//          'r'   'v'   'p'   ' '
//           \     |     |     /
//            \    \     /    /
//              \   \   /    /
//                -- '@' --
//
//    '#'  top, result of conflict merge
//    'r'  reference type
//    'v'  value type
//    'p'  pc type for jsr/ret
//    ' '  uninitialized; never occurs on operand stack in Java
//    '@'  bottom/unexecuted; initial state each bytecode.
//
//    Basic block headers are the only merge points. We use this iteration to
//    compute the information:
//
//    find basic blocks;
//    initialize them with uninitialized state;
//    initialize first BB according to method signature;
//    mark first BB changed
//    while (some BB is changed) do {
//      perform abstract interpration of all bytecodes in BB;
//      merge exit state of BB into entry state of all successor BBs,
//      noting if any of these change;
//    }
//
//  One additional complication is necessary. The jsr instruction pushes
//  a return PC on the stack (a 'p' type in the abstract interpretation).
//  To be able to process "ret" bytecodes, we keep track of these return
//  PC's in a 'retAddrs' structure in abstract interpreter context (when
//  processing a "ret" bytecodes, it is not sufficient to know that it gets
//  an argument of the right type 'p'; we need to know which address it
//  returns to).
//
// (Note this comment is borrowed form the original author of the algorithm)

#include "incls/_precompiled.incl"
#include "incls/_generateOopMap.cpp.incl"

// ComputeCallStack
//
// Specialization of SignatureIterator - compute the effects of a call
//
class ComputeCallStack : public SignatureIterator {
  CellTypeState *_effect;
  int _idx;

  void setup();
  void set(CellTypeState state)         { _effect[_idx++] = state; }
  int  length()                         { return _idx; };

  virtual void do_bool  ()              { set(CellTypeState::value); };
  virtual void do_char  ()              { set(CellTypeState::value); };
  virtual void do_float ()              { set(CellTypeState::value); };
  virtual void do_byte  ()              { set(CellTypeState::value); };
  virtual void do_short ()              { set(CellTypeState::value); };
  virtual void do_int   ()              { set(CellTypeState::value); };
  virtual void do_void  ()              { set(CellTypeState::bottom);};
  virtual void do_object(int begin, int end)  { set(CellTypeState::ref); };
  virtual void do_array (int begin, int end)  { set(CellTypeState::ref); };

  void do_double()                      { set(CellTypeState::value);
                                          set(CellTypeState::value); }
  void do_long  ()                      { set(CellTypeState::value);
                                           set(CellTypeState::value); }

public:
  ComputeCallStack(symbolOop signature) : SignatureIterator(signature) {};

  // Compute methods
  int compute_for_parameters(bool is_static, CellTypeState *effect) {
    _idx    = 0;
    _effect = effect;

    if (!is_static)
      effect[_idx++] = CellTypeState::ref;

    iterate_parameters();

    return length();
  };

  int compute_for_returntype(CellTypeState *effect) {
    _idx    = 0;
    _effect = effect;
    iterate_returntype();
    set(CellTypeState::bottom);  // Always terminate with a bottom state, so ppush works

    return length();
  }
};

//=========================================================================================
// ComputeEntryStack
//
// Specialization of SignatureIterator - in order to set up first stack frame
//
class ComputeEntryStack : public SignatureIterator {
  CellTypeState *_effect;
  int _idx;

  void setup();
  void set(CellTypeState state)         { _effect[_idx++] = state; }
  int  length()                         { return _idx; };

  virtual void do_bool  ()              { set(CellTypeState::value); };
  virtual void do_char  ()              { set(CellTypeState::value); };
  virtual void do_float ()              { set(CellTypeState::value); };
  virtual void do_byte  ()              { set(CellTypeState::value); };
  virtual void do_short ()              { set(CellTypeState::value); };
  virtual void do_int   ()              { set(CellTypeState::value); };
  virtual void do_void  ()              { set(CellTypeState::bottom);};
  virtual void do_object(int begin, int end)  { set(CellTypeState::make_slot_ref(_idx)); }
  virtual void do_array (int begin, int end)  { set(CellTypeState::make_slot_ref(_idx)); }

  void do_double()                      { set(CellTypeState::value);
                                          set(CellTypeState::value); }
  void do_long  ()                      { set(CellTypeState::value);
                                          set(CellTypeState::value); }

public:
  ComputeEntryStack(symbolOop signature) : SignatureIterator(signature) {};

  // Compute methods
  int compute_for_parameters(bool is_static, CellTypeState *effect) {
    _idx    = 0;
    _effect = effect;

    if (!is_static)
      effect[_idx++] = CellTypeState::make_slot_ref(0);

    iterate_parameters();

    return length();
  };

  int compute_for_returntype(CellTypeState *effect) {
    _idx    = 0;
    _effect = effect;
    iterate_returntype();
    set(CellTypeState::bottom);  // Always terminate with a bottom state, so ppush works

    return length();
  }
};

//=====================================================================================
//
// Implementation of RetTable/RetTableEntry
//
// Contains function to itereate through all bytecodes
// and find all return entry points
//
int RetTable::_init_nof_entries = 10;
int RetTableEntry::_init_nof_jsrs = 5;

void RetTableEntry::add_delta(int bci, int delta) {
  if (_target_bci > bci) _target_bci += delta;

  for (int k = 0; k < _jsrs->length(); k++) {
    int jsr = _jsrs->at(k);
    if (jsr > bci) _jsrs->at_put(k, jsr+delta);
  }
}

void RetTable::compute_ret_table(methodHandle method) {
  BytecodeStream i(method);
  Bytecodes::Code bytecode;

  while( (bytecode = i.next()) >= 0) {
    switch (bytecode) {
      case Bytecodes::_jsr:
        add_jsr(i.next_bci(), i.dest());
        break;
      case Bytecodes::_jsr_w:
        add_jsr(i.next_bci(), i.dest_w());
        break;
    }
  }
}

void RetTable::add_jsr(int return_bci, int target_bci) {
  RetTableEntry* entry = _first;

  // Scan table for entry
  for (;entry && entry->target_bci() != target_bci; entry = entry->next());

  if (!entry) {
    // Allocate new entry and put in list
    entry = new RetTableEntry(target_bci, _first);
    _first = entry;
  }

  // Now "entry" is set.  Make sure that the entry is initialized
  // and has room for the new jsr.
  entry->add_jsr(return_bci);
}

RetTableEntry* RetTable::find_jsrs_for_target(int targBci) {
  RetTableEntry *cur = _first;

  while(cur) {
    assert(cur->target_bci() != -1, "sanity check");
    if (cur->target_bci() == targBci)  return cur;
    cur = cur->next();
  }
  ShouldNotReachHere();
  return NULL;
}

// The instruction at bci is changing size by "delta".  Update the return map.
void RetTable::update_ret_table(int bci, int delta) {
  RetTableEntry *cur = _first;
  while(cur) {
    cur->add_delta(bci, delta);
    cur = cur->next();
  }
}

//
// Celltype state
//

CellTypeState CellTypeState::bottom      = CellTypeState::make_bottom();
CellTypeState CellTypeState::uninit      = CellTypeState::make_any(uninit_value);
CellTypeState CellTypeState::ref         = CellTypeState::make_any(ref_conflict);
CellTypeState CellTypeState::value       = CellTypeState::make_any(val_value);
CellTypeState CellTypeState::refUninit   = CellTypeState::make_any(ref_conflict | uninit_value);
CellTypeState CellTypeState::top         = CellTypeState::make_top();
CellTypeState CellTypeState::addr        = CellTypeState::make_any(addr_conflict);

// Commonly used constants
static CellTypeState epsilonCTS[1] = { CellTypeState::bottom };
static CellTypeState   refCTS   = CellTypeState::ref;
static CellTypeState   valCTS   = CellTypeState::value;
static CellTypeState    vCTS[2] = { CellTypeState::value, CellTypeState::bottom };
static CellTypeState    rCTS[2] = { CellTypeState::ref,   CellTypeState::bottom };
static CellTypeState   rrCTS[3] = { CellTypeState::ref,   CellTypeState::ref,   CellTypeState::bottom };
static CellTypeState   vrCTS[3] = { CellTypeState::value, CellTypeState::ref,   CellTypeState::bottom };
static CellTypeState   vvCTS[3] = { CellTypeState::value, CellTypeState::value, CellTypeState::bottom };
static CellTypeState  rvrCTS[4] = { CellTypeState::ref,   CellTypeState::value, CellTypeState::ref,   CellTypeState::bottom };
static CellTypeState  vvrCTS[4] = { CellTypeState::value, CellTypeState::value, CellTypeState::ref,   CellTypeState::bottom };
static CellTypeState  vvvCTS[4] = { CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::bottom };
static CellTypeState vvvrCTS[5] = { CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::ref,   CellTypeState::bottom };
static CellTypeState vvvvCTS[5] = { CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::value, CellTypeState::bottom };

char CellTypeState::to_char() const {
  if (can_be_reference()) {
    if (can_be_value() || can_be_address())
      return '#';    // Conflict that needs to be rewritten
    else
      return 'r';
  } else if (can_be_value())
    return 'v';
  else if (can_be_address())
    return 'p';
  else if (can_be_uninit())
    return ' ';
  else
    return '@';
}


// Print a detailed CellTypeState.  Indicate all bits that are set.  If
// the CellTypeState represents an address or a reference, print the
// value of the additional information.
void CellTypeState::print(outputStream *os) {
  if (can_be_address()) {
    os->print("(p");
  } else {
    os->print("( ");
  }
  if (can_be_reference()) {
    os->print("r");
  } else {
    os->print(" ");
  }
  if (can_be_value()) {
    os->print("v");
  } else {
    os->print(" ");
  }
  if (can_be_uninit()) {
    os->print("u|");
  } else {
    os->print(" |");
  }
  if (is_info_top()) {
    os->print("Top)");
  } else if (is_info_bottom()) {
    os->print("Bot)");
  } else {
    if (is_reference()) {
      int info = get_info();
      int data = info & ~(ref_not_lock_bit | ref_slot_bit);
      if (info & ref_not_lock_bit) {
        // Not a monitor lock reference.
        if (info & ref_slot_bit) {
          // slot
          os->print("slot%d)", data);
        } else {
          // line
          os->print("line%d)", data);
        }
      } else {
        // lock
        os->print("lock%d)", data);
      }
    } else {
      os->print("%d)", get_info());
    }
  }
}

//
// Basicblock handling methods
//

void GenerateOopMap ::initialize_bb() {
  _gc_points = 0;
  _bb_count  = 0;
373 374
  _bb_hdr_bits.clear();
  _bb_hdr_bits.resize(method()->code_size());
D
duke 已提交
375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809
}

void GenerateOopMap::bb_mark_fct(GenerateOopMap *c, int bci, int *data) {
  assert(bci>= 0 && bci < c->method()->code_size(), "index out of bounds");
  if (c->is_bb_header(bci))
     return;

  if (TraceNewOopMapGeneration) {
     tty->print_cr("Basicblock#%d begins at: %d", c->_bb_count, bci);
  }
  c->set_bbmark_bit(bci);
  c->_bb_count++;
}


void GenerateOopMap::mark_bbheaders_and_count_gc_points() {
  initialize_bb();

  bool fellThrough = false;  // False to get first BB marked.

  // First mark all exception handlers as start of a basic-block
  typeArrayOop excps = method()->exception_table();
  for(int i = 0; i < excps->length(); i += 4) {
    int handler_pc_idx = i+2;
    bb_mark_fct(this, excps->int_at(handler_pc_idx), NULL);
  }

  // Then iterate through the code
  BytecodeStream bcs(_method);
  Bytecodes::Code bytecode;

  while( (bytecode = bcs.next()) >= 0) {
    int bci = bcs.bci();

    if (!fellThrough)
        bb_mark_fct(this, bci, NULL);

    fellThrough = jump_targets_do(&bcs, &GenerateOopMap::bb_mark_fct, NULL);

     /* We will also mark successors of jsr's as basic block headers. */
    switch (bytecode) {
      case Bytecodes::_jsr:
        assert(!fellThrough, "should not happen");
        bb_mark_fct(this, bci + Bytecodes::length_for(bytecode), NULL);
        break;
      case Bytecodes::_jsr_w:
        assert(!fellThrough, "should not happen");
        bb_mark_fct(this, bci + Bytecodes::length_for(bytecode), NULL);
        break;
    }

    if (possible_gc_point(&bcs))
      _gc_points++;
  }
}

void GenerateOopMap::reachable_basicblock(GenerateOopMap *c, int bci, int *data) {
  assert(bci>= 0 && bci < c->method()->code_size(), "index out of bounds");
  BasicBlock* bb = c->get_basic_block_at(bci);
  if (bb->is_dead()) {
    bb->mark_as_alive();
    *data = 1; // Mark basicblock as changed
  }
}


void GenerateOopMap::mark_reachable_code() {
  int change = 1; // int to get function pointers to work

  // Mark entry basic block as alive and all exception handlers
  _basic_blocks[0].mark_as_alive();
  typeArrayOop excps = method()->exception_table();
  for(int i = 0; i < excps->length(); i += 4) {
    int handler_pc_idx = i+2;
    BasicBlock *bb = get_basic_block_at(excps->int_at(handler_pc_idx));
    // If block is not already alive (due to multiple exception handlers to same bb), then
    // make it alive
    if (bb->is_dead()) bb->mark_as_alive();
  }

  BytecodeStream bcs(_method);

  // Iterate through all basic blocks until we reach a fixpoint
  while (change) {
    change = 0;

    for (int i = 0; i < _bb_count; i++) {
      BasicBlock *bb = &_basic_blocks[i];
      if (bb->is_alive()) {
        // Position bytecodestream at last bytecode in basicblock
        bcs.set_start(bb->_end_bci);
        bcs.next();
        Bytecodes::Code bytecode = bcs.code();
        int bci = bcs.bci();
        assert(bci == bb->_end_bci, "wrong bci");

        bool fell_through = jump_targets_do(&bcs, &GenerateOopMap::reachable_basicblock, &change);

        // We will also mark successors of jsr's as alive.
        switch (bytecode) {
          case Bytecodes::_jsr:
          case Bytecodes::_jsr_w:
            assert(!fell_through, "should not happen");
            reachable_basicblock(this, bci + Bytecodes::length_for(bytecode), &change);
            break;
        }
        if (fell_through) {
          // Mark successor as alive
          if (bb[1].is_dead()) {
            bb[1].mark_as_alive();
            change = 1;
          }
        }
      }
    }
  }
}

/* If the current instruction in "c" has no effect on control flow,
   returns "true".  Otherwise, calls "jmpFct" one or more times, with
   "c", an appropriate "pcDelta", and "data" as arguments, then
   returns "false".  There is one exception: if the current
   instruction is a "ret", returns "false" without calling "jmpFct".
   Arrangements for tracking the control flow of a "ret" must be made
   externally. */
bool GenerateOopMap::jump_targets_do(BytecodeStream *bcs, jmpFct_t jmpFct, int *data) {
  int bci = bcs->bci();

  switch (bcs->code()) {
    case Bytecodes::_ifeq:
    case Bytecodes::_ifne:
    case Bytecodes::_iflt:
    case Bytecodes::_ifge:
    case Bytecodes::_ifgt:
    case Bytecodes::_ifle:
    case Bytecodes::_if_icmpeq:
    case Bytecodes::_if_icmpne:
    case Bytecodes::_if_icmplt:
    case Bytecodes::_if_icmpge:
    case Bytecodes::_if_icmpgt:
    case Bytecodes::_if_icmple:
    case Bytecodes::_if_acmpeq:
    case Bytecodes::_if_acmpne:
    case Bytecodes::_ifnull:
    case Bytecodes::_ifnonnull:
      (*jmpFct)(this, bcs->dest(), data);
      (*jmpFct)(this, bci + 3, data);
      break;

    case Bytecodes::_goto:
      (*jmpFct)(this, bcs->dest(), data);
      break;
    case Bytecodes::_goto_w:
      (*jmpFct)(this, bcs->dest_w(), data);
      break;
    case Bytecodes::_tableswitch:
      { Bytecode_tableswitch *tableswitch = Bytecode_tableswitch_at(bcs->bcp());
        int len = tableswitch->length();

        (*jmpFct)(this, bci + tableswitch->default_offset(), data); /* Default. jump address */
        while (--len >= 0) {
          (*jmpFct)(this, bci + tableswitch->dest_offset_at(len), data);
        }
        break;
      }

    case Bytecodes::_lookupswitch:
      { Bytecode_lookupswitch *lookupswitch = Bytecode_lookupswitch_at(bcs->bcp());
        int npairs = lookupswitch->number_of_pairs();
        (*jmpFct)(this, bci + lookupswitch->default_offset(), data); /* Default. */
        while(--npairs >= 0) {
          LookupswitchPair *pair = lookupswitch->pair_at(npairs);
          (*jmpFct)(this, bci + pair->offset(), data);
        }
        break;
      }
    case Bytecodes::_jsr:
      assert(bcs->is_wide()==false, "sanity check");
      (*jmpFct)(this, bcs->dest(), data);



      break;
    case Bytecodes::_jsr_w:
      (*jmpFct)(this, bcs->dest_w(), data);
      break;
    case Bytecodes::_wide:
      ShouldNotReachHere();
      return true;
      break;
    case Bytecodes::_athrow:
    case Bytecodes::_ireturn:
    case Bytecodes::_lreturn:
    case Bytecodes::_freturn:
    case Bytecodes::_dreturn:
    case Bytecodes::_areturn:
    case Bytecodes::_return:
    case Bytecodes::_ret:
      break;
    default:
      return true;
  }
  return false;
}

/* Requires "pc" to be the head of a basic block; returns that basic
   block. */
BasicBlock *GenerateOopMap::get_basic_block_at(int bci) const {
  BasicBlock* bb = get_basic_block_containing(bci);
  assert(bb->_bci == bci, "should have found BB");
  return bb;
}

// Requires "pc" to be the start of an instruction; returns the basic
//   block containing that instruction. */
BasicBlock  *GenerateOopMap::get_basic_block_containing(int bci) const {
  BasicBlock *bbs = _basic_blocks;
  int lo = 0, hi = _bb_count - 1;

  while (lo <= hi) {
    int m = (lo + hi) / 2;
    int mbci = bbs[m]._bci;
    int nbci;

    if ( m == _bb_count-1) {
      assert( bci >= mbci && bci < method()->code_size(), "sanity check failed");
      return bbs+m;
    } else {
      nbci = bbs[m+1]._bci;
    }

    if ( mbci <= bci && bci < nbci) {
      return bbs+m;
    } else if (mbci < bci) {
      lo = m + 1;
    } else {
      assert(mbci > bci, "sanity check");
      hi = m - 1;
    }
  }

  fatal("should have found BB");
  return NULL;
}

void GenerateOopMap::restore_state(BasicBlock *bb)
{
  memcpy(_state, bb->_state, _state_len*sizeof(CellTypeState));
  _stack_top = bb->_stack_top;
  _monitor_top = bb->_monitor_top;
}

int GenerateOopMap::next_bb_start_pc(BasicBlock *bb) {
 int bbNum = bb - _basic_blocks + 1;
 if (bbNum == _bb_count)
    return method()->code_size();

 return _basic_blocks[bbNum]._bci;
}

//
// CellType handling methods
//

void GenerateOopMap::init_state() {
  _state_len     = _max_locals + _max_stack + _max_monitors;
  _state         = NEW_RESOURCE_ARRAY(CellTypeState, _state_len);
  memset(_state, 0, _state_len * sizeof(CellTypeState));
  _state_vec_buf = NEW_RESOURCE_ARRAY(char, MAX3(_max_locals, _max_stack, _max_monitors) + 1/*for null terminator char */);
}

void GenerateOopMap::make_context_uninitialized() {
  CellTypeState* vs = vars();

  for (int i = 0; i < _max_locals; i++)
      vs[i] = CellTypeState::uninit;

  _stack_top = 0;
  _monitor_top = 0;
}

int GenerateOopMap::methodsig_to_effect(symbolOop signature, bool is_static, CellTypeState* effect) {
  ComputeEntryStack ces(signature);
  return ces.compute_for_parameters(is_static, effect);
}

// Return result of merging cts1 and cts2.
CellTypeState CellTypeState::merge(CellTypeState cts, int slot) const {
  CellTypeState result;

  assert(!is_bottom() && !cts.is_bottom(),
         "merge of bottom values is handled elsewhere");

  result._state = _state | cts._state;

  // If the top bit is set, we don't need to do any more work.
  if (!result.is_info_top()) {
    assert((result.can_be_address() || result.can_be_reference()),
           "only addresses and references have non-top info");

    if (!equal(cts)) {
      // The two values being merged are different.  Raise to top.
      if (result.is_reference()) {
        result = CellTypeState::make_slot_ref(slot);
      } else {
        result._state |= info_conflict;
      }
    }
  }
  assert(result.is_valid_state(), "checking that CTS merge maintains legal state");

  return result;
}

// Merge the variable state for locals and stack from cts into bbts.
bool GenerateOopMap::merge_local_state_vectors(CellTypeState* cts,
                                               CellTypeState* bbts) {
  int i;
  int len = _max_locals + _stack_top;
  bool change = false;

  for (i = len - 1; i >= 0; i--) {
    CellTypeState v = cts[i].merge(bbts[i], i);
    change = change || !v.equal(bbts[i]);
    bbts[i] = v;
  }

  return change;
}

// Merge the monitor stack state from cts into bbts.
bool GenerateOopMap::merge_monitor_state_vectors(CellTypeState* cts,
                                                 CellTypeState* bbts) {
  bool change = false;
  if (_max_monitors > 0 && _monitor_top != bad_monitors) {
    // If there are no monitors in the program, or there has been
    // a monitor matching error before this point in the program,
    // then we do not merge in the monitor state.

    int base = _max_locals + _max_stack;
    int len = base + _monitor_top;
    for (int i = len - 1; i >= base; i--) {
      CellTypeState v = cts[i].merge(bbts[i], i);

      // Can we prove that, when there has been a change, it will already
      // have been detected at this point?  That would make this equal
      // check here unnecessary.
      change = change || !v.equal(bbts[i]);
      bbts[i] = v;
    }
  }

  return change;
}

void GenerateOopMap::copy_state(CellTypeState *dst, CellTypeState *src) {
  int len = _max_locals + _stack_top;
  for (int i = 0; i < len; i++) {
    if (src[i].is_nonlock_reference()) {
      dst[i] = CellTypeState::make_slot_ref(i);
    } else {
      dst[i] = src[i];
    }
  }
  if (_max_monitors > 0 && _monitor_top != bad_monitors) {
    int base = _max_locals + _max_stack;
    len = base + _monitor_top;
    for (int i = base; i < len; i++) {
      dst[i] = src[i];
    }
  }
}


// Merge the states for the current block and the next.  As long as a
// block is reachable the locals and stack must be merged.  If the
// stack heights don't match then this is a verification error and
// it's impossible to interpret the code.  Simultaneously monitor
// states are being check to see if they nest statically.  If monitor
// depths match up then their states are merged.  Otherwise the
// mismatch is simply recorded and interpretation continues since
// monitor matching is purely informational and doesn't say anything
// about the correctness of the code.
void GenerateOopMap::merge_state_into_bb(BasicBlock *bb) {
  assert(bb->is_alive(), "merging state into a dead basicblock");

  if (_stack_top == bb->_stack_top) {
    // always merge local state even if monitors don't match.
    if (merge_local_state_vectors(_state, bb->_state)) {
      bb->set_changed(true);
    }
    if (_monitor_top == bb->_monitor_top) {
      // monitors still match so continue merging monitor states.
      if (merge_monitor_state_vectors(_state, bb->_state)) {
        bb->set_changed(true);
      }
    } else {
      if (TraceMonitorMismatch) {
        report_monitor_mismatch("monitor stack height merge conflict");
      }
      // When the monitor stacks are not matched, we set _monitor_top to
      // bad_monitors.  This signals that, from here on, the monitor stack cannot
      // be trusted.  In particular, monitorexit bytecodes may throw
      // exceptions.  We mark this block as changed so that the change
      // propagates properly.
      bb->_monitor_top = bad_monitors;
      bb->set_changed(true);
      _monitor_safe = false;
    }
  } else if (!bb->is_reachable()) {
    // First time we look at this  BB
    copy_state(bb->_state, _state);
    bb->_stack_top = _stack_top;
    bb->_monitor_top = _monitor_top;
    bb->set_changed(true);
  } else {
    verify_error("stack height conflict: %d vs. %d",  _stack_top, bb->_stack_top);
  }
}

void GenerateOopMap::merge_state(GenerateOopMap *gom, int bci, int* data) {
   gom->merge_state_into_bb(gom->get_basic_block_at(bci));
}

void GenerateOopMap::set_var(int localNo, CellTypeState cts) {
  assert(cts.is_reference() || cts.is_value() || cts.is_address(),
         "wrong celltypestate");
  if (localNo < 0 || localNo > _max_locals) {
    verify_error("variable write error: r%d", localNo);
    return;
  }
  vars()[localNo] = cts;
}

CellTypeState GenerateOopMap::get_var(int localNo) {
810
  assert(localNo < _max_locals + _nof_refval_conflicts, "variable read error");
D
duke 已提交
811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941
  if (localNo < 0 || localNo > _max_locals) {
    verify_error("variable read error: r%d", localNo);
    return valCTS; // just to pick something;
  }
  return vars()[localNo];
}

CellTypeState GenerateOopMap::pop() {
  if ( _stack_top <= 0) {
    verify_error("stack underflow");
    return valCTS; // just to pick something
  }
  return  stack()[--_stack_top];
}

void GenerateOopMap::push(CellTypeState cts) {
  if ( _stack_top >= _max_stack) {
    verify_error("stack overflow");
    return;
  }
  stack()[_stack_top++] = cts;
}

CellTypeState GenerateOopMap::monitor_pop() {
  assert(_monitor_top != bad_monitors, "monitor_pop called on error monitor stack");
  if (_monitor_top == 0) {
    // We have detected a pop of an empty monitor stack.
    _monitor_safe = false;
     _monitor_top = bad_monitors;

    if (TraceMonitorMismatch) {
      report_monitor_mismatch("monitor stack underflow");
    }
    return CellTypeState::ref; // just to keep the analysis going.
  }
  return  monitors()[--_monitor_top];
}

void GenerateOopMap::monitor_push(CellTypeState cts) {
  assert(_monitor_top != bad_monitors, "monitor_push called on error monitor stack");
  if (_monitor_top >= _max_monitors) {
    // Some monitorenter is being executed more than once.
    // This means that the monitor stack cannot be simulated.
    _monitor_safe = false;
    _monitor_top = bad_monitors;

    if (TraceMonitorMismatch) {
      report_monitor_mismatch("monitor stack overflow");
    }
    return;
  }
  monitors()[_monitor_top++] = cts;
}

//
// Interpretation handling methods
//

void GenerateOopMap::do_interpretation()
{
  // "i" is just for debugging, so we can detect cases where this loop is
  // iterated more than once.
  int i = 0;
  do {
#ifndef PRODUCT
    if (TraceNewOopMapGeneration) {
      tty->print("\n\nIteration #%d of do_interpretation loop, method:\n", i);
      method()->print_name(tty);
      tty->print("\n\n");
    }
#endif
    _conflict = false;
    _monitor_safe = true;
    // init_state is now called from init_basic_blocks.  The length of a
    // state vector cannot be determined until we have made a pass through
    // the bytecodes counting the possible monitor entries.
    if (!_got_error) init_basic_blocks();
    if (!_got_error) setup_method_entry_state();
    if (!_got_error) interp_all();
    if (!_got_error) rewrite_refval_conflicts();
    i++;
  } while (_conflict && !_got_error);
}

void GenerateOopMap::init_basic_blocks() {
  // Note: Could consider reserving only the needed space for each BB's state
  // (entry stack may not be of maximal height for every basic block).
  // But cumbersome since we don't know the stack heights yet.  (Nor the
  // monitor stack heights...)

  _basic_blocks = NEW_RESOURCE_ARRAY(BasicBlock, _bb_count);

  // Make a pass through the bytecodes.  Count the number of monitorenters.
  // This can be used an upper bound on the monitor stack depth in programs
  // which obey stack discipline with their monitor usage.  Initialize the
  // known information about basic blocks.
  BytecodeStream j(_method);
  Bytecodes::Code bytecode;

  int bbNo = 0;
  int monitor_count = 0;
  int prev_bci = -1;
  while( (bytecode = j.next()) >= 0) {
    if (j.code() == Bytecodes::_monitorenter) {
      monitor_count++;
    }

    int bci = j.bci();
    if (is_bb_header(bci)) {
      // Initialize the basicblock structure
      BasicBlock *bb   = _basic_blocks + bbNo;
      bb->_bci         = bci;
      bb->_max_locals  = _max_locals;
      bb->_max_stack   = _max_stack;
      bb->set_changed(false);
      bb->_stack_top   = BasicBlock::_dead_basic_block; // Initialize all basicblocks are dead.
      bb->_monitor_top = bad_monitors;

      if (bbNo > 0) {
        _basic_blocks[bbNo - 1]._end_bci = prev_bci;
      }

      bbNo++;
    }
    // Remember prevous bci.
    prev_bci = bci;
  }
  // Set
  _basic_blocks[bbNo-1]._end_bci = prev_bci;


942 943 944 945 946 947 948 949 950 951 952
  // Check that the correct number of basicblocks was found
  if (bbNo !=_bb_count) {
    if (bbNo < _bb_count) {
      verify_error("jump into the middle of instruction?");
      return;
    } else {
      verify_error("extra basic blocks - should not happen?");
      return;
    }
  }

D
duke 已提交
953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012
  _max_monitors = monitor_count;

  // Now that we have a bound on the depth of the monitor stack, we can
  // initialize the CellTypeState-related information.
  init_state();

  // We allocate space for all state-vectors for all basicblocks in one huge chuck.
  // Then in the next part of the code, we set a pointer in each _basic_block that
  // points to each piece.
  CellTypeState *basicBlockState = NEW_RESOURCE_ARRAY(CellTypeState, bbNo * _state_len);
  memset(basicBlockState, 0, bbNo * _state_len * sizeof(CellTypeState));

  // Make a pass over the basicblocks and assign their state vectors.
  for (int blockNum=0; blockNum < bbNo; blockNum++) {
    BasicBlock *bb = _basic_blocks + blockNum;
    bb->_state = basicBlockState + blockNum * _state_len;

#ifdef ASSERT
    if (blockNum + 1 < bbNo) {
      address bcp = _method->bcp_from(bb->_end_bci);
      int bc_len = Bytecodes::java_length_at(bcp);
      assert(bb->_end_bci + bc_len == bb[1]._bci, "unmatched bci info in basicblock");
    }
#endif
  }
#ifdef ASSERT
  { BasicBlock *bb = &_basic_blocks[bbNo-1];
    address bcp = _method->bcp_from(bb->_end_bci);
    int bc_len = Bytecodes::java_length_at(bcp);
    assert(bb->_end_bci + bc_len == _method->code_size(), "wrong end bci");
  }
#endif

  // Mark all alive blocks
  mark_reachable_code();
}

void GenerateOopMap::setup_method_entry_state() {

    // Initialize all locals to 'uninit' and set stack-height to 0
    make_context_uninitialized();

    // Initialize CellState type of arguments
    methodsig_to_effect(method()->signature(), method()->is_static(), vars());

    // If some references must be pre-assigned to null, then set that up
    initialize_vars();

    // This is the start state
    merge_state_into_bb(&_basic_blocks[0]);

    assert(_basic_blocks[0].changed(), "we are not getting off the ground");
}

// The instruction at bci is changing size by "delta".  Update the basic blocks.
void GenerateOopMap::update_basic_blocks(int bci, int delta,
                                         int new_method_size) {
  assert(new_method_size >= method()->code_size() + delta,
         "new method size is too small");

1013 1014 1015 1016 1017 1018
  BitMap::bm_word_t* new_bb_hdr_bits =
    NEW_RESOURCE_ARRAY(BitMap::bm_word_t,
                       BitMap::word_align_up(new_method_size));
  _bb_hdr_bits.set_map(new_bb_hdr_bits);
  _bb_hdr_bits.set_size(new_method_size);
  _bb_hdr_bits.clear();
D
duke 已提交
1019 1020 1021 1022 1023 1024 1025


  for(int k = 0; k < _bb_count; k++) {
    if (_basic_blocks[k]._bci > bci) {
      _basic_blocks[k]._bci     += delta;
      _basic_blocks[k]._end_bci += delta;
    }
1026
    _bb_hdr_bits.at_put(_basic_blocks[k]._bci, true);
D
duke 已提交
1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254
  }
}

//
// Initvars handling
//

void GenerateOopMap::initialize_vars() {
  for (int k = 0; k < _init_vars->length(); k++)
    _state[_init_vars->at(k)] = CellTypeState::make_slot_ref(k);
}

void GenerateOopMap::add_to_ref_init_set(int localNo) {

  if (TraceNewOopMapGeneration)
    tty->print_cr("Added init vars: %d", localNo);

  // Is it already in the set?
  if (_init_vars->contains(localNo) )
    return;

   _init_vars->append(localNo);
}

//
// Interpreration code
//

void GenerateOopMap::interp_all() {
  bool change = true;

  while (change && !_got_error) {
    change = false;
    for (int i = 0; i < _bb_count && !_got_error; i++) {
      BasicBlock *bb = &_basic_blocks[i];
      if (bb->changed()) {
         if (_got_error) return;
         change = true;
         bb->set_changed(false);
         interp_bb(bb);
      }
    }
  }
}

void GenerateOopMap::interp_bb(BasicBlock *bb) {

  // We do not want to do anything in case the basic-block has not been initialized. This
  // will happen in the case where there is dead-code hang around in a method.
  assert(bb->is_reachable(), "should be reachable or deadcode exist");
  restore_state(bb);

  BytecodeStream itr(_method);

  // Set iterator interval to be the current basicblock
  int lim_bci = next_bb_start_pc(bb);
  itr.set_interval(bb->_bci, lim_bci);
  assert(lim_bci != bb->_bci, "must be at least one instruction in a basicblock");
  itr.next(); // read first instruction

  // Iterates through all bytecodes except the last in a basic block.
  // We handle the last one special, since there is controlflow change.
  while(itr.next_bci() < lim_bci && !_got_error) {
    if (_has_exceptions || _monitor_top != 0) {
      // We do not need to interpret the results of exceptional
      // continuation from this instruction when the method has no
      // exception handlers and the monitor stack is currently
      // empty.
      do_exception_edge(&itr);
    }
    interp1(&itr);
    itr.next();
  }

  // Handle last instruction.
  if (!_got_error) {
    assert(itr.next_bci() == lim_bci, "must point to end");
    if (_has_exceptions || _monitor_top != 0) {
      do_exception_edge(&itr);
    }
    interp1(&itr);

    bool fall_through = jump_targets_do(&itr, GenerateOopMap::merge_state, NULL);
    if (_got_error)  return;

    if (itr.code() == Bytecodes::_ret) {
      assert(!fall_through, "cannot be set if ret instruction");
      // Automatically handles 'wide' ret indicies
      ret_jump_targets_do(&itr, GenerateOopMap::merge_state, itr.get_index(), NULL);
    } else if (fall_through) {
     // Hit end of BB, but the instr. was a fall-through instruction,
     // so perform transition as if the BB ended in a "jump".
     if (lim_bci != bb[1]._bci) {
       verify_error("bytecodes fell through last instruction");
       return;
     }
     merge_state_into_bb(bb + 1);
    }
  }
}

void GenerateOopMap::do_exception_edge(BytecodeStream* itr) {
  // Only check exception edge, if bytecode can trap
  if (!Bytecodes::can_trap(itr->code())) return;
  switch (itr->code()) {
    case Bytecodes::_aload_0:
      // These bytecodes can trap for rewriting.  We need to assume that
      // they do not throw exceptions to make the monitor analysis work.
      return;

    case Bytecodes::_ireturn:
    case Bytecodes::_lreturn:
    case Bytecodes::_freturn:
    case Bytecodes::_dreturn:
    case Bytecodes::_areturn:
    case Bytecodes::_return:
      // If the monitor stack height is not zero when we leave the method,
      // then we are either exiting with a non-empty stack or we have
      // found monitor trouble earlier in our analysis.  In either case,
      // assume an exception could be taken here.
      if (_monitor_top == 0) {
        return;
      }
      break;

    case Bytecodes::_monitorexit:
      // If the monitor stack height is bad_monitors, then we have detected a
      // monitor matching problem earlier in the analysis.  If the
      // monitor stack height is 0, we are about to pop a monitor
      // off of an empty stack.  In either case, the bytecode
      // could throw an exception.
      if (_monitor_top != bad_monitors && _monitor_top != 0) {
        return;
      }
      break;
  }

  if (_has_exceptions) {
    int bci = itr->bci();
    typeArrayOop exct  = method()->exception_table();
    for(int i = 0; i< exct->length(); i+=4) {
      int start_pc   = exct->int_at(i);
      int end_pc     = exct->int_at(i+1);
      int handler_pc = exct->int_at(i+2);
      int catch_type = exct->int_at(i+3);

      if (start_pc <= bci && bci < end_pc) {
        BasicBlock *excBB = get_basic_block_at(handler_pc);
        CellTypeState *excStk = excBB->stack();
        CellTypeState *cOpStck = stack();
        CellTypeState cOpStck_0 = cOpStck[0];
        int cOpStackTop = _stack_top;

        // Exception stacks are always the same.
        assert(method()->max_stack() > 0, "sanity check");

        // We remembered the size and first element of "cOpStck"
        // above; now we temporarily set them to the appropriate
        // values for an exception handler. */
        cOpStck[0] = CellTypeState::make_slot_ref(_max_locals);
        _stack_top = 1;

        merge_state_into_bb(excBB);

        // Now undo the temporary change.
        cOpStck[0] = cOpStck_0;
        _stack_top = cOpStackTop;

        // If this is a "catch all" handler, then we do not need to
        // consider any additional handlers.
        if (catch_type == 0) {
          return;
        }
      }
    }
  }

  // It is possible that none of the exception handlers would have caught
  // the exception.  In this case, we will exit the method.  We must
  // ensure that the monitor stack is empty in this case.
  if (_monitor_top == 0) {
    return;
  }

  // We pessimistically assume that this exception can escape the
  // method. (It is possible that it will always be caught, but
  // we don't care to analyse the types of the catch clauses.)

  // We don't set _monitor_top to bad_monitors because there are no successors
  // to this exceptional exit.

  if (TraceMonitorMismatch && _monitor_safe) {
    // We check _monitor_safe so that we only report the first mismatched
    // exceptional exit.
    report_monitor_mismatch("non-empty monitor stack at exceptional exit");
  }
  _monitor_safe = false;

}

void GenerateOopMap::report_monitor_mismatch(const char *msg) {
#ifndef PRODUCT
  tty->print("    Monitor mismatch in method ");
  method()->print_short_name(tty);
  tty->print_cr(": %s", msg);
#endif
}

void GenerateOopMap::print_states(outputStream *os,
                                  CellTypeState* vec, int num) {
  for (int i = 0; i < num; i++) {
    vec[i].print(tty);
  }
}

// Print the state values at the current bytecode.
void GenerateOopMap::print_current_state(outputStream   *os,
                                         BytecodeStream *currentBC,
                                         bool            detailed) {

  if (detailed) {
    os->print("     %4d vars     = ", currentBC->bci());
    print_states(os, vars(), _max_locals);
    os->print("    %s", Bytecodes::name(currentBC->code()));
    switch(currentBC->code()) {
      case Bytecodes::_invokevirtual:
      case Bytecodes::_invokespecial:
      case Bytecodes::_invokestatic:
1255
      case Bytecodes::_invokedynamic:
D
duke 已提交
1256
      case Bytecodes::_invokeinterface:
1257
        int idx = currentBC->has_index_u4() ? currentBC->get_index_u4() : currentBC->get_index_u2();
D
duke 已提交
1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286
        constantPoolOop cp    = method()->constants();
        int nameAndTypeIdx    = cp->name_and_type_ref_index_at(idx);
        int signatureIdx      = cp->signature_ref_index_at(nameAndTypeIdx);
        symbolOop signature   = cp->symbol_at(signatureIdx);
        os->print("%s", signature->as_C_string());
    }
    os->cr();
    os->print("          stack    = ");
    print_states(os, stack(), _stack_top);
    os->cr();
    if (_monitor_top != bad_monitors) {
      os->print("          monitors = ");
      print_states(os, monitors(), _monitor_top);
    } else {
      os->print("          [bad monitor stack]");
    }
    os->cr();
  } else {
    os->print("    %4d  vars = '%s' ", currentBC->bci(),  state_vec_to_string(vars(), _max_locals));
    os->print("     stack = '%s' ", state_vec_to_string(stack(), _stack_top));
    if (_monitor_top != bad_monitors) {
      os->print("  monitors = '%s'  \t%s", state_vec_to_string(monitors(), _monitor_top), Bytecodes::name(currentBC->code()));
    } else {
      os->print("  [bad monitor stack]");
    }
    switch(currentBC->code()) {
      case Bytecodes::_invokevirtual:
      case Bytecodes::_invokespecial:
      case Bytecodes::_invokestatic:
1287
      case Bytecodes::_invokedynamic:
D
duke 已提交
1288
      case Bytecodes::_invokeinterface:
1289
        int idx = currentBC->has_index_u4() ? currentBC->get_index_u4() : currentBC->get_index_u2();
D
duke 已提交
1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314
        constantPoolOop cp    = method()->constants();
        int nameAndTypeIdx    = cp->name_and_type_ref_index_at(idx);
        int signatureIdx      = cp->signature_ref_index_at(nameAndTypeIdx);
        symbolOop signature   = cp->symbol_at(signatureIdx);
        os->print("%s", signature->as_C_string());
    }
    os->cr();
  }
}

// Sets the current state to be the state after executing the
// current instruction, starting in the current state.
void GenerateOopMap::interp1(BytecodeStream *itr) {
  if (TraceNewOopMapGeneration) {
    print_current_state(tty, itr, TraceNewOopMapGenerationDetailed);
  }

  // Should we report the results? Result is reported *before* the instruction at the current bci is executed.
  // However, not for calls. For calls we do not want to include the arguments, so we postpone the reporting until
  // they have been popped (in method ppl).
  if (_report_result == true) {
    switch(itr->code()) {
      case Bytecodes::_invokevirtual:
      case Bytecodes::_invokespecial:
      case Bytecodes::_invokestatic:
1315
      case Bytecodes::_invokedynamic:
D
duke 已提交
1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358
      case Bytecodes::_invokeinterface:
        _itr_send = itr;
        _report_result_for_send = true;
        break;
      default:
       fill_stackmap_for_opcodes(itr, vars(), stack(), _stack_top);
       break;
    }
  }

  // abstract interpretation of current opcode
  switch(itr->code()) {
    case Bytecodes::_nop:                                           break;
    case Bytecodes::_goto:                                          break;
    case Bytecodes::_goto_w:                                        break;
    case Bytecodes::_iinc:                                          break;
    case Bytecodes::_return:            do_return_monitor_check();
                                        break;

    case Bytecodes::_aconst_null:
    case Bytecodes::_new:               ppush1(CellTypeState::make_line_ref(itr->bci()));
                                        break;

    case Bytecodes::_iconst_m1:
    case Bytecodes::_iconst_0:
    case Bytecodes::_iconst_1:
    case Bytecodes::_iconst_2:
    case Bytecodes::_iconst_3:
    case Bytecodes::_iconst_4:
    case Bytecodes::_iconst_5:
    case Bytecodes::_fconst_0:
    case Bytecodes::_fconst_1:
    case Bytecodes::_fconst_2:
    case Bytecodes::_bipush:
    case Bytecodes::_sipush:            ppush1(valCTS);             break;

    case Bytecodes::_lconst_0:
    case Bytecodes::_lconst_1:
    case Bytecodes::_dconst_0:
    case Bytecodes::_dconst_1:          ppush(vvCTS);               break;

    case Bytecodes::_ldc2_w:            ppush(vvCTS);               break;

1359 1360
    case Bytecodes::_ldc:               do_ldc(itr->get_index(),    itr->bci()); break;
    case Bytecodes::_ldc_w:             do_ldc(itr->get_index_u2(), itr->bci()); break;
D
duke 已提交
1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552

    case Bytecodes::_iload:
    case Bytecodes::_fload:             ppload(vCTS, itr->get_index()); break;

    case Bytecodes::_lload:
    case Bytecodes::_dload:             ppload(vvCTS,itr->get_index()); break;

    case Bytecodes::_aload:             ppload(rCTS, itr->get_index()); break;

    case Bytecodes::_iload_0:
    case Bytecodes::_fload_0:           ppload(vCTS, 0);            break;
    case Bytecodes::_iload_1:
    case Bytecodes::_fload_1:           ppload(vCTS, 1);            break;
    case Bytecodes::_iload_2:
    case Bytecodes::_fload_2:           ppload(vCTS, 2);            break;
    case Bytecodes::_iload_3:
    case Bytecodes::_fload_3:           ppload(vCTS, 3);            break;

    case Bytecodes::_lload_0:
    case Bytecodes::_dload_0:           ppload(vvCTS, 0);           break;
    case Bytecodes::_lload_1:
    case Bytecodes::_dload_1:           ppload(vvCTS, 1);           break;
    case Bytecodes::_lload_2:
    case Bytecodes::_dload_2:           ppload(vvCTS, 2);           break;
    case Bytecodes::_lload_3:
    case Bytecodes::_dload_3:           ppload(vvCTS, 3);           break;

    case Bytecodes::_aload_0:           ppload(rCTS, 0);            break;
    case Bytecodes::_aload_1:           ppload(rCTS, 1);            break;
    case Bytecodes::_aload_2:           ppload(rCTS, 2);            break;
    case Bytecodes::_aload_3:           ppload(rCTS, 3);            break;

    case Bytecodes::_iaload:
    case Bytecodes::_faload:
    case Bytecodes::_baload:
    case Bytecodes::_caload:
    case Bytecodes::_saload:            pp(vrCTS, vCTS); break;

    case Bytecodes::_laload:            pp(vrCTS, vvCTS);  break;
    case Bytecodes::_daload:            pp(vrCTS, vvCTS); break;

    case Bytecodes::_aaload:            pp_new_ref(vrCTS, itr->bci()); break;

    case Bytecodes::_istore:
    case Bytecodes::_fstore:            ppstore(vCTS, itr->get_index()); break;

    case Bytecodes::_lstore:
    case Bytecodes::_dstore:            ppstore(vvCTS, itr->get_index()); break;

    case Bytecodes::_astore:            do_astore(itr->get_index());     break;

    case Bytecodes::_istore_0:
    case Bytecodes::_fstore_0:          ppstore(vCTS, 0);           break;
    case Bytecodes::_istore_1:
    case Bytecodes::_fstore_1:          ppstore(vCTS, 1);           break;
    case Bytecodes::_istore_2:
    case Bytecodes::_fstore_2:          ppstore(vCTS, 2);           break;
    case Bytecodes::_istore_3:
    case Bytecodes::_fstore_3:          ppstore(vCTS, 3);           break;

    case Bytecodes::_lstore_0:
    case Bytecodes::_dstore_0:          ppstore(vvCTS, 0);          break;
    case Bytecodes::_lstore_1:
    case Bytecodes::_dstore_1:          ppstore(vvCTS, 1);          break;
    case Bytecodes::_lstore_2:
    case Bytecodes::_dstore_2:          ppstore(vvCTS, 2);          break;
    case Bytecodes::_lstore_3:
    case Bytecodes::_dstore_3:          ppstore(vvCTS, 3);          break;

    case Bytecodes::_astore_0:          do_astore(0);               break;
    case Bytecodes::_astore_1:          do_astore(1);               break;
    case Bytecodes::_astore_2:          do_astore(2);               break;
    case Bytecodes::_astore_3:          do_astore(3);               break;

    case Bytecodes::_iastore:
    case Bytecodes::_fastore:
    case Bytecodes::_bastore:
    case Bytecodes::_castore:
    case Bytecodes::_sastore:           ppop(vvrCTS);               break;
    case Bytecodes::_lastore:
    case Bytecodes::_dastore:           ppop(vvvrCTS);              break;
    case Bytecodes::_aastore:           ppop(rvrCTS);               break;

    case Bytecodes::_pop:               ppop_any(1);                break;
    case Bytecodes::_pop2:              ppop_any(2);                break;

    case Bytecodes::_dup:               ppdupswap(1, "11");         break;
    case Bytecodes::_dup_x1:            ppdupswap(2, "121");        break;
    case Bytecodes::_dup_x2:            ppdupswap(3, "1321");       break;
    case Bytecodes::_dup2:              ppdupswap(2, "2121");       break;
    case Bytecodes::_dup2_x1:           ppdupswap(3, "21321");      break;
    case Bytecodes::_dup2_x2:           ppdupswap(4, "214321");     break;
    case Bytecodes::_swap:              ppdupswap(2, "12");         break;

    case Bytecodes::_iadd:
    case Bytecodes::_fadd:
    case Bytecodes::_isub:
    case Bytecodes::_fsub:
    case Bytecodes::_imul:
    case Bytecodes::_fmul:
    case Bytecodes::_idiv:
    case Bytecodes::_fdiv:
    case Bytecodes::_irem:
    case Bytecodes::_frem:
    case Bytecodes::_ishl:
    case Bytecodes::_ishr:
    case Bytecodes::_iushr:
    case Bytecodes::_iand:
    case Bytecodes::_ior:
    case Bytecodes::_ixor:
    case Bytecodes::_l2f:
    case Bytecodes::_l2i:
    case Bytecodes::_d2f:
    case Bytecodes::_d2i:
    case Bytecodes::_fcmpl:
    case Bytecodes::_fcmpg:             pp(vvCTS, vCTS); break;

    case Bytecodes::_ladd:
    case Bytecodes::_dadd:
    case Bytecodes::_lsub:
    case Bytecodes::_dsub:
    case Bytecodes::_lmul:
    case Bytecodes::_dmul:
    case Bytecodes::_ldiv:
    case Bytecodes::_ddiv:
    case Bytecodes::_lrem:
    case Bytecodes::_drem:
    case Bytecodes::_land:
    case Bytecodes::_lor:
    case Bytecodes::_lxor:              pp(vvvvCTS, vvCTS); break;

    case Bytecodes::_ineg:
    case Bytecodes::_fneg:
    case Bytecodes::_i2f:
    case Bytecodes::_f2i:
    case Bytecodes::_i2c:
    case Bytecodes::_i2s:
    case Bytecodes::_i2b:               pp(vCTS, vCTS); break;

    case Bytecodes::_lneg:
    case Bytecodes::_dneg:
    case Bytecodes::_l2d:
    case Bytecodes::_d2l:               pp(vvCTS, vvCTS); break;

    case Bytecodes::_lshl:
    case Bytecodes::_lshr:
    case Bytecodes::_lushr:             pp(vvvCTS, vvCTS); break;

    case Bytecodes::_i2l:
    case Bytecodes::_i2d:
    case Bytecodes::_f2l:
    case Bytecodes::_f2d:               pp(vCTS, vvCTS); break;

    case Bytecodes::_lcmp:              pp(vvvvCTS, vCTS); break;
    case Bytecodes::_dcmpl:
    case Bytecodes::_dcmpg:             pp(vvvvCTS, vCTS); break;

    case Bytecodes::_ifeq:
    case Bytecodes::_ifne:
    case Bytecodes::_iflt:
    case Bytecodes::_ifge:
    case Bytecodes::_ifgt:
    case Bytecodes::_ifle:
    case Bytecodes::_tableswitch:       ppop1(valCTS);
                                        break;
    case Bytecodes::_ireturn:
    case Bytecodes::_freturn:           do_return_monitor_check();
                                        ppop1(valCTS);
                                        break;
    case Bytecodes::_if_icmpeq:
    case Bytecodes::_if_icmpne:
    case Bytecodes::_if_icmplt:
    case Bytecodes::_if_icmpge:
    case Bytecodes::_if_icmpgt:
    case Bytecodes::_if_icmple:         ppop(vvCTS);
                                        break;

    case Bytecodes::_lreturn:           do_return_monitor_check();
                                        ppop(vvCTS);
                                        break;

    case Bytecodes::_dreturn:           do_return_monitor_check();
                                        ppop(vvCTS);
                                        break;

    case Bytecodes::_if_acmpeq:
    case Bytecodes::_if_acmpne:         ppop(rrCTS);                 break;

    case Bytecodes::_jsr:               do_jsr(itr->dest());         break;
    case Bytecodes::_jsr_w:             do_jsr(itr->dest_w());       break;

    case Bytecodes::_getstatic:         do_field(true,  true,
1553
                                                 itr->get_index_u2_cpcache(),
D
duke 已提交
1554
                                                 itr->bci()); break;
1555 1556 1557
    case Bytecodes::_putstatic:         do_field(false, true,  itr->get_index_u2_cpcache(), itr->bci()); break;
    case Bytecodes::_getfield:          do_field(true,  false, itr->get_index_u2_cpcache(), itr->bci()); break;
    case Bytecodes::_putfield:          do_field(false, false, itr->get_index_u2_cpcache(), itr->bci()); break;
D
duke 已提交
1558

1559
    case Bytecodes::_invokevirtual:
1560 1561 1562 1563
    case Bytecodes::_invokespecial:     do_method(false, false, itr->get_index_u2_cpcache(), itr->bci()); break;
    case Bytecodes::_invokestatic:      do_method(true,  false, itr->get_index_u2_cpcache(), itr->bci()); break;
    case Bytecodes::_invokedynamic:     do_method(true,  false, itr->get_index_u4(),         itr->bci()); break;
    case Bytecodes::_invokeinterface:   do_method(false, true,  itr->get_index_u2_cpcache(), itr->bci()); break;
1564 1565
    case Bytecodes::_newarray:
    case Bytecodes::_anewarray:         pp_new_ref(vCTS, itr->bci()); break;
D
duke 已提交
1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832
    case Bytecodes::_checkcast:         do_checkcast(); break;
    case Bytecodes::_arraylength:
    case Bytecodes::_instanceof:        pp(rCTS, vCTS); break;
    case Bytecodes::_monitorenter:      do_monitorenter(itr->bci()); break;
    case Bytecodes::_monitorexit:       do_monitorexit(itr->bci()); break;

    case Bytecodes::_athrow:            // handled by do_exception_edge() BUT ...
                                        // vlh(apple): do_exception_edge() does not get
                                        // called if method has no exception handlers
                                        if ((!_has_exceptions) && (_monitor_top > 0)) {
                                          _monitor_safe = false;
                                        }
                                        break;

    case Bytecodes::_areturn:           do_return_monitor_check();
                                        ppop1(refCTS);
                                        break;
    case Bytecodes::_ifnull:
    case Bytecodes::_ifnonnull:         ppop1(refCTS); break;
    case Bytecodes::_multianewarray:    do_multianewarray(*(itr->bcp()+3), itr->bci()); break;

    case Bytecodes::_wide:              fatal("Iterator should skip this bytecode"); break;
    case Bytecodes::_ret:                                           break;

    // Java opcodes
    case Bytecodes::_lookupswitch:      ppop1(valCTS);             break;

    default:
         tty->print("unexpected opcode: %d\n", itr->code());
         ShouldNotReachHere();
    break;
  }
}

void GenerateOopMap::check_type(CellTypeState expected, CellTypeState actual) {
  if (!expected.equal_kind(actual)) {
    verify_error("wrong type on stack (found: %c expected: %c)", actual.to_char(), expected.to_char());
  }
}

void GenerateOopMap::ppstore(CellTypeState *in, int loc_no) {
  while(!(*in).is_bottom()) {
    CellTypeState expected =*in++;
    CellTypeState actual   = pop();
    check_type(expected, actual);
    assert(loc_no >= 0, "sanity check");
    set_var(loc_no++, actual);
  }
}

void GenerateOopMap::ppload(CellTypeState *out, int loc_no) {
  while(!(*out).is_bottom()) {
    CellTypeState out1 = *out++;
    CellTypeState vcts = get_var(loc_no);
    assert(out1.can_be_reference() || out1.can_be_value(),
           "can only load refs. and values.");
    if (out1.is_reference()) {
      assert(loc_no>=0, "sanity check");
      if (!vcts.is_reference()) {
        // We were asked to push a reference, but the type of the
        // variable can be something else
        _conflict = true;
        if (vcts.can_be_uninit()) {
          // It is a ref-uninit conflict (at least). If there are other
          // problems, we'll get them in the next round
          add_to_ref_init_set(loc_no);
          vcts = out1;
        } else {
          // It wasn't a ref-uninit conflict. So must be a
          // ref-val or ref-pc conflict. Split the variable.
          record_refval_conflict(loc_no);
          vcts = out1;
        }
        push(out1); // recover...
      } else {
        push(vcts); // preserve reference.
      }
      // Otherwise it is a conflict, but one that verification would
      // have caught if illegal. In particular, it can't be a topCTS
      // resulting from mergeing two difference pcCTS's since the verifier
      // would have rejected any use of such a merge.
    } else {
      push(out1); // handle val/init conflict
    }
    loc_no++;
  }
}

void GenerateOopMap::ppdupswap(int poplen, const char *out) {
  CellTypeState actual[5];
  assert(poplen < 5, "this must be less than length of actual vector");

  // pop all arguments
  for(int i = 0; i < poplen; i++) actual[i] = pop();

  // put them back
  char push_ch = *out++;
  while (push_ch != '\0') {
    int idx = push_ch - '1';
    assert(idx >= 0 && idx < poplen, "wrong arguments");
    push(actual[idx]);
    push_ch = *out++;
  }
}

void GenerateOopMap::ppop1(CellTypeState out) {
  CellTypeState actual = pop();
  check_type(out, actual);
}

void GenerateOopMap::ppop(CellTypeState *out) {
  while (!(*out).is_bottom()) {
    ppop1(*out++);
  }
}

void GenerateOopMap::ppush1(CellTypeState in) {
  assert(in.is_reference() | in.is_value(), "sanity check");
  push(in);
}

void GenerateOopMap::ppush(CellTypeState *in) {
  while (!(*in).is_bottom()) {
    ppush1(*in++);
  }
}

void GenerateOopMap::pp(CellTypeState *in, CellTypeState *out) {
  ppop(in);
  ppush(out);
}

void GenerateOopMap::pp_new_ref(CellTypeState *in, int bci) {
  ppop(in);
  ppush1(CellTypeState::make_line_ref(bci));
}

void GenerateOopMap::ppop_any(int poplen) {
  if (_stack_top >= poplen) {
    _stack_top -= poplen;
  } else {
    verify_error("stack underflow");
  }
}

// Replace all occurences of the state 'match' with the state 'replace'
// in our current state vector.
void GenerateOopMap::replace_all_CTS_matches(CellTypeState match,
                                             CellTypeState replace) {
  int i;
  int len = _max_locals + _stack_top;
  bool change = false;

  for (i = len - 1; i >= 0; i--) {
    if (match.equal(_state[i])) {
      _state[i] = replace;
    }
  }

  if (_monitor_top > 0) {
    int base = _max_locals + _max_stack;
    len = base + _monitor_top;
    for (i = len - 1; i >= base; i--) {
      if (match.equal(_state[i])) {
        _state[i] = replace;
      }
    }
  }
}

void GenerateOopMap::do_checkcast() {
  CellTypeState actual = pop();
  check_type(refCTS, actual);
  push(actual);
}

void GenerateOopMap::do_monitorenter(int bci) {
  CellTypeState actual = pop();
  if (_monitor_top == bad_monitors) {
    return;
  }

  // Bail out when we get repeated locks on an identical monitor.  This case
  // isn't too hard to handle and can be made to work if supporting nested
  // redundant synchronized statements becomes a priority.
  //
  // See also "Note" in do_monitorexit(), below.
  if (actual.is_lock_reference()) {
    _monitor_top = bad_monitors;
    _monitor_safe = false;

    if (TraceMonitorMismatch) {
      report_monitor_mismatch("nested redundant lock -- bailout...");
    }
    return;
  }

  CellTypeState lock = CellTypeState::make_lock_ref(bci);
  check_type(refCTS, actual);
  if (!actual.is_info_top()) {
    replace_all_CTS_matches(actual, lock);
    monitor_push(lock);
  }
}

void GenerateOopMap::do_monitorexit(int bci) {
  CellTypeState actual = pop();
  if (_monitor_top == bad_monitors) {
    return;
  }
  check_type(refCTS, actual);
  CellTypeState expected = monitor_pop();
  if (!actual.is_lock_reference() || !expected.equal(actual)) {
    // The monitor we are exiting is not verifiably the one
    // on the top of our monitor stack.  This causes a monitor
    // mismatch.
    _monitor_top = bad_monitors;
    _monitor_safe = false;

    // We need to mark this basic block as changed so that
    // this monitorexit will be visited again.  We need to
    // do this to ensure that we have accounted for the
    // possibility that this bytecode will throw an
    // exception.
    BasicBlock* bb = get_basic_block_containing(bci);
    bb->set_changed(true);
    bb->_monitor_top = bad_monitors;

    if (TraceMonitorMismatch) {
      report_monitor_mismatch("improper monitor pair");
    }
  } else {
    // This code is a fix for the case where we have repeated
    // locking of the same object in straightline code.  We clear
    // out the lock when it is popped from the monitor stack
    // and replace it with an unobtrusive reference value that can
    // be locked again.
    //
    // Note: when generateOopMap is fixed to properly handle repeated,
    //       nested, redundant locks on the same object, then this
    //       fix will need to be removed at that time.
    replace_all_CTS_matches(actual, CellTypeState::make_line_ref(bci));
  }
}

void GenerateOopMap::do_return_monitor_check() {
  if (_monitor_top > 0) {
    // The monitor stack must be empty when we leave the method
    // for the monitors to be properly matched.
    _monitor_safe = false;

    // Since there are no successors to the *return bytecode, it
    // isn't necessary to set _monitor_top to bad_monitors.

    if (TraceMonitorMismatch) {
      report_monitor_mismatch("non-empty monitor stack at return");
    }
  }
}

void GenerateOopMap::do_jsr(int targ_bci) {
  push(CellTypeState::make_addr(targ_bci));
}



void GenerateOopMap::do_ldc(int idx, int bci) {
1833 1834
  constantPoolOop cp  = method()->constants();
  CellTypeState   cts = cp->is_pointer_entry(idx) ? CellTypeState::make_line_ref(bci) : valCTS;
D
duke 已提交
1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898
  ppush1(cts);
}

void GenerateOopMap::do_multianewarray(int dims, int bci) {
  assert(dims >= 1, "sanity check");
  for(int i = dims -1; i >=0; i--) {
    ppop1(valCTS);
  }
  ppush1(CellTypeState::make_line_ref(bci));
}

void GenerateOopMap::do_astore(int idx) {
  CellTypeState r_or_p = pop();
  if (!r_or_p.is_address() && !r_or_p.is_reference()) {
    // We actually expected ref or pc, but we only report that we expected a ref. It does not
    // really matter (at least for now)
    verify_error("wrong type on stack (found: %c, expected: {pr})", r_or_p.to_char());
    return;
  }
  set_var(idx, r_or_p);
}

// Copies bottom/zero terminated CTS string from "src" into "dst".
//   Does NOT terminate with a bottom. Returns the number of cells copied.
int GenerateOopMap::copy_cts(CellTypeState *dst, CellTypeState *src) {
  int idx = 0;
  while (!src[idx].is_bottom()) {
    dst[idx] = src[idx];
    idx++;
  }
  return idx;
}

void GenerateOopMap::do_field(int is_get, int is_static, int idx, int bci) {
  // Dig up signature for field in constant pool
  constantPoolOop cp     = method()->constants();
  int nameAndTypeIdx     = cp->name_and_type_ref_index_at(idx);
  int signatureIdx       = cp->signature_ref_index_at(nameAndTypeIdx);
  symbolOop signature    = cp->symbol_at(signatureIdx);

  // Parse signature (espcially simple for fields)
  assert(signature->utf8_length() > 0, "field signatures cannot have zero length");
  // The signature is UFT8 encoded, but the first char is always ASCII for signatures.
  char sigch = (char)*(signature->base());
  CellTypeState temp[4];
  CellTypeState *eff  = sigchar_to_effect(sigch, bci, temp);

  CellTypeState in[4];
  CellTypeState *out;
  int i =  0;

  if (is_get) {
    out = eff;
  } else {
    out = epsilonCTS;
    i   = copy_cts(in, eff);
  }
  if (!is_static) in[i++] = CellTypeState::ref;
  in[i] = CellTypeState::bottom;
  assert(i<=3, "sanity check");
  pp(in, out);
}

void GenerateOopMap::do_method(int is_static, int is_interface, int idx, int bci) {
1899 1900 1901
 // Dig up signature for field in constant pool
  constantPoolOop cp  = _method->constants();
  symbolOop signature = cp->signature_ref_at(idx);
D
duke 已提交
1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003

  // Parse method signature
  CellTypeState out[4];
  CellTypeState in[MAXARGSIZE+1];   // Includes result
  ComputeCallStack cse(signature);

  // Compute return type
  int res_length=  cse.compute_for_returntype(out);

  // Temporary hack.
  if (out[0].equal(CellTypeState::ref) && out[1].equal(CellTypeState::bottom)) {
    out[0] = CellTypeState::make_line_ref(bci);
  }

  assert(res_length<=4, "max value should be vv");

  // Compute arguments
  int arg_length = cse.compute_for_parameters(is_static != 0, in);
  assert(arg_length<=MAXARGSIZE, "too many locals");

  // Pop arguments
  for (int i = arg_length - 1; i >= 0; i--) ppop1(in[i]);// Do args in reverse order.

  // Report results
  if (_report_result_for_send == true) {
     fill_stackmap_for_opcodes(_itr_send, vars(), stack(), _stack_top);
     _report_result_for_send = false;
  }

  // Push return address
  ppush(out);
}

// This is used to parse the signature for fields, since they are very simple...
CellTypeState *GenerateOopMap::sigchar_to_effect(char sigch, int bci, CellTypeState *out) {
  // Object and array
  if (sigch=='L' || sigch=='[') {
    out[0] = CellTypeState::make_line_ref(bci);
    out[1] = CellTypeState::bottom;
    return out;
  }
  if (sigch == 'J' || sigch == 'D' ) return vvCTS;  // Long and Double
  if (sigch == 'V' ) return epsilonCTS;             // Void
  return vCTS;                                      // Otherwise
}

long GenerateOopMap::_total_byte_count = 0;
elapsedTimer GenerateOopMap::_total_oopmap_time;

// This function assumes "bcs" is at a "ret" instruction and that the vars
// state is valid for that instruction. Furthermore, the ret instruction
// must be the last instruction in "bb" (we store information about the
// "ret" in "bb").
void GenerateOopMap::ret_jump_targets_do(BytecodeStream *bcs, jmpFct_t jmpFct, int varNo, int *data) {
  CellTypeState ra = vars()[varNo];
  if (!ra.is_good_address()) {
    verify_error("ret returns from two jsr subroutines?");
    return;
  }
  int target = ra.get_info();

  RetTableEntry* rtEnt = _rt.find_jsrs_for_target(target);
  int bci = bcs->bci();
  for (int i = 0; i < rtEnt->nof_jsrs(); i++) {
    int target_bci = rtEnt->jsrs(i);
    // Make sure a jrtRet does not set the changed bit for dead basicblock.
    BasicBlock* jsr_bb    = get_basic_block_containing(target_bci - 1);
    debug_only(BasicBlock* target_bb = &jsr_bb[1];)
    assert(target_bb  == get_basic_block_at(target_bci), "wrong calc. of successor basicblock");
    bool alive = jsr_bb->is_alive();
    if (TraceNewOopMapGeneration) {
      tty->print("pc = %d, ret -> %d alive: %s\n", bci, target_bci, alive ? "true" : "false");
    }
    if (alive) jmpFct(this, target_bci, data);
  }
}

//
// Debug method
//
char* GenerateOopMap::state_vec_to_string(CellTypeState* vec, int len) {
#ifdef ASSERT
  int checklen = MAX3(_max_locals, _max_stack, _max_monitors) + 1;
  assert(len < checklen, "state_vec_buf overflow");
#endif
  for (int i = 0; i < len; i++) _state_vec_buf[i] = vec[i].to_char();
  _state_vec_buf[len] = 0;
  return _state_vec_buf;
}

void GenerateOopMap::print_time() {
  tty->print_cr ("Accumulated oopmap times:");
  tty->print_cr ("---------------------------");
  tty->print_cr ("  Total : %3.3f sec.", GenerateOopMap::_total_oopmap_time.seconds());
  tty->print_cr ("  (%3.0f bytecodes per sec) ",
  GenerateOopMap::_total_byte_count / GenerateOopMap::_total_oopmap_time.seconds());
}

//
//  ============ Main Entry Point ===========
//
GenerateOopMap::GenerateOopMap(methodHandle method) {
T
twisti 已提交
2004
  // We have to initialize all variables here, that can be queried directly
D
duke 已提交
2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522
  _method = method;
  _max_locals=0;
  _init_vars = NULL;

#ifndef PRODUCT
  // If we are doing a detailed trace, include the regular trace information.
  if (TraceNewOopMapGenerationDetailed) {
    TraceNewOopMapGeneration = true;
  }
#endif
}

void GenerateOopMap::compute_map(TRAPS) {
#ifndef PRODUCT
  if (TimeOopMap2) {
    method()->print_short_name(tty);
    tty->print("  ");
  }
  if (TimeOopMap) {
    _total_byte_count += method()->code_size();
  }
#endif
  TraceTime t_single("oopmap time", TimeOopMap2);
  TraceTime t_all(NULL, &_total_oopmap_time, TimeOopMap);

  // Initialize values
  _got_error      = false;
  _conflict       = false;
  _max_locals     = method()->max_locals();
  _max_stack      = method()->max_stack();
  _has_exceptions = (method()->exception_table()->length() > 0);
  _nof_refval_conflicts = 0;
  _init_vars      = new GrowableArray<intptr_t>(5);  // There are seldom more than 5 init_vars
  _report_result  = false;
  _report_result_for_send = false;
  _new_var_map    = NULL;
  _ret_adr_tos    = new GrowableArray<intptr_t>(5);  // 5 seems like a good number;
  _did_rewriting  = false;
  _did_relocation = false;

  if (TraceNewOopMapGeneration) {
    tty->print("Method name: %s\n", method()->name()->as_C_string());
    if (Verbose) {
      _method->print_codes();
      tty->print_cr("Exception table:");
      typeArrayOop excps = method()->exception_table();
      for(int i = 0; i < excps->length(); i += 4) {
        tty->print_cr("[%d - %d] -> %d", excps->int_at(i + 0), excps->int_at(i + 1), excps->int_at(i + 2));
      }
    }
  }

  // if no code - do nothing
  // compiler needs info
  if (method()->code_size() == 0 || _max_locals + method()->max_stack() == 0) {
    fill_stackmap_prolog(0);
    fill_stackmap_epilog();
    return;
  }
  // Step 1: Compute all jump targets and their return value
  if (!_got_error)
    _rt.compute_ret_table(_method);

  // Step 2: Find all basic blocks and count GC points
  if (!_got_error)
    mark_bbheaders_and_count_gc_points();

  // Step 3: Calculate stack maps
  if (!_got_error)
    do_interpretation();

  // Step 4:Return results
  if (!_got_error && report_results())
     report_result();

  if (_got_error) {
    THROW_HANDLE(_exception);
  }
}

// Error handling methods
// These methods create an exception for the current thread which is thrown
// at the bottom of the call stack, when it returns to compute_map().  The
// _got_error flag controls execution.  NOT TODO: The VM exception propagation
// mechanism using TRAPS/CHECKs could be used here instead but it would need
// to be added as a parameter to every function and checked for every call.
// The tons of extra code it would generate didn't seem worth the change.
//
void GenerateOopMap::error_work(const char *format, va_list ap) {
  _got_error = true;
  char msg_buffer[512];
  vsnprintf(msg_buffer, sizeof(msg_buffer), format, ap);
  // Append method name
  char msg_buffer2[512];
  jio_snprintf(msg_buffer2, sizeof(msg_buffer2), "%s in method %s", msg_buffer, method()->name()->as_C_string());
  _exception = Exceptions::new_exception(Thread::current(),
                vmSymbols::java_lang_LinkageError(), msg_buffer2);
}

void GenerateOopMap::report_error(const char *format, ...) {
  va_list ap;
  va_start(ap, format);
  error_work(format, ap);
}

void GenerateOopMap::verify_error(const char *format, ...) {
  // We do not distinguish between different types of errors for verification
  // errors.  Let the verifier give a better message.
  const char *msg = "Illegal class file encountered. Try running with -Xverify:all";
  error_work(msg, NULL);
}

//
// Report result opcodes
//
void GenerateOopMap::report_result() {

  if (TraceNewOopMapGeneration) tty->print_cr("Report result pass");

  // We now want to report the result of the parse
  _report_result = true;

  // Prolog code
  fill_stackmap_prolog(_gc_points);

   // Mark everything changed, then do one interpretation pass.
  for (int i = 0; i<_bb_count; i++) {
    if (_basic_blocks[i].is_reachable()) {
      _basic_blocks[i].set_changed(true);
      interp_bb(&_basic_blocks[i]);
    }
  }

  // Note: Since we are skipping dead-code when we are reporting results, then
  // the no. of encountered gc-points might be fewer than the previously number
  // we have counted. (dead-code is a pain - it should be removed before we get here)
  fill_stackmap_epilog();

  // Report initvars
  fill_init_vars(_init_vars);

  _report_result = false;
}

void GenerateOopMap::result_for_basicblock(int bci) {
 if (TraceNewOopMapGeneration) tty->print_cr("Report result pass for basicblock");

  // We now want to report the result of the parse
  _report_result = true;

  // Find basicblock and report results
  BasicBlock* bb = get_basic_block_containing(bci);
  assert(bb->is_reachable(), "getting result from unreachable basicblock");
  bb->set_changed(true);
  interp_bb(bb);
}

//
// Conflict handling code
//

void GenerateOopMap::record_refval_conflict(int varNo) {
  assert(varNo>=0 && varNo< _max_locals, "index out of range");

  if (TraceOopMapRewrites) {
     tty->print("### Conflict detected (local no: %d)\n", varNo);
  }

  if (!_new_var_map) {
    _new_var_map = NEW_RESOURCE_ARRAY(int, _max_locals);
    for (int k = 0; k < _max_locals; k++)  _new_var_map[k] = k;
  }

  if ( _new_var_map[varNo] == varNo) {
    // Check if max. number of locals has been reached
    if (_max_locals + _nof_refval_conflicts >= MAX_LOCAL_VARS) {
      report_error("Rewriting exceeded local variable limit");
      return;
    }
    _new_var_map[varNo] = _max_locals + _nof_refval_conflicts;
    _nof_refval_conflicts++;
  }
}

void GenerateOopMap::rewrite_refval_conflicts()
{
  // We can get here two ways: Either a rewrite conflict was detected, or
  // an uninitialize reference was detected. In the second case, we do not
  // do any rewriting, we just want to recompute the reference set with the
  // new information

  int nof_conflicts = 0;              // Used for debugging only

  if ( _nof_refval_conflicts == 0 )
     return;

  // Check if rewrites are allowed in this parse.
  if (!allow_rewrites() && !IgnoreRewrites) {
    fatal("Rewriting method not allowed at this stage");
  }


  // This following flag is to tempoary supress rewrites. The locals that might conflict will
  // all be set to contain values. This is UNSAFE - however, until the rewriting has been completely
  // tested it is nice to have.
  if (IgnoreRewrites) {
    if (Verbose) {
       tty->print("rewrites suppressed for local no. ");
       for (int l = 0; l < _max_locals; l++) {
         if (_new_var_map[l] != l) {
           tty->print("%d ", l);
           vars()[l] = CellTypeState::value;
         }
       }
       tty->cr();
    }

    // That was that...
    _new_var_map = NULL;
    _nof_refval_conflicts = 0;
    _conflict = false;

    return;
  }

  // Tracing flag
  _did_rewriting = true;

  if (TraceOopMapRewrites) {
    tty->print_cr("ref/value conflict for method %s - bytecodes are getting rewritten", method()->name()->as_C_string());
    method()->print();
    method()->print_codes();
  }

  assert(_new_var_map!=NULL, "nothing to rewrite");
  assert(_conflict==true, "We should not be here");

  compute_ret_adr_at_TOS();
  if (!_got_error) {
    for (int k = 0; k < _max_locals && !_got_error; k++) {
      if (_new_var_map[k] != k) {
        if (TraceOopMapRewrites) {
          tty->print_cr("Rewriting: %d -> %d", k, _new_var_map[k]);
        }
        rewrite_refval_conflict(k, _new_var_map[k]);
        if (_got_error) return;
        nof_conflicts++;
      }
    }
  }

  assert(nof_conflicts == _nof_refval_conflicts, "sanity check");

  // Adjust the number of locals
  method()->set_max_locals(_max_locals+_nof_refval_conflicts);
  _max_locals += _nof_refval_conflicts;

  // That was that...
  _new_var_map = NULL;
  _nof_refval_conflicts = 0;
}

void GenerateOopMap::rewrite_refval_conflict(int from, int to) {
  bool startOver;
  do {
    // Make sure that the BytecodeStream is constructed in the loop, since
    // during rewriting a new method oop is going to be used, and the next time
    // around we want to use that.
    BytecodeStream bcs(_method);
    startOver = false;

    while( bcs.next() >=0 && !startOver && !_got_error) {
      startOver = rewrite_refval_conflict_inst(&bcs, from, to);
    }
  } while (startOver && !_got_error);
}

/* If the current instruction is one that uses local variable "from"
   in a ref way, change it to use "to". There's a subtle reason why we
   renumber the ref uses and not the non-ref uses: non-ref uses may be
   2 slots wide (double, long) which would necessitate keeping track of
   whether we should add one or two variables to the method. If the change
   affected the width of some instruction, returns "TRUE"; otherwise, returns "FALSE".
   Another reason for moving ref's value is for solving (addr, ref) conflicts, which
   both uses aload/astore methods.
*/
bool GenerateOopMap::rewrite_refval_conflict_inst(BytecodeStream *itr, int from, int to) {
  Bytecodes::Code bc = itr->code();
  int index;
  int bci = itr->bci();

  if (is_aload(itr, &index) && index == from) {
    if (TraceOopMapRewrites) {
      tty->print_cr("Rewriting aload at bci: %d", bci);
    }
    return rewrite_load_or_store(itr, Bytecodes::_aload, Bytecodes::_aload_0, to);
  }

  if (is_astore(itr, &index) && index == from) {
    if (!stack_top_holds_ret_addr(bci)) {
      if (TraceOopMapRewrites) {
        tty->print_cr("Rewriting astore at bci: %d", bci);
      }
      return rewrite_load_or_store(itr, Bytecodes::_astore, Bytecodes::_astore_0, to);
    } else {
      if (TraceOopMapRewrites) {
        tty->print_cr("Supress rewriting of astore at bci: %d", bci);
      }
    }
  }

  return false;
}

// The argument to this method is:
// bc : Current bytecode
// bcN : either _aload or _astore
// bc0 : either _aload_0 or _astore_0
bool GenerateOopMap::rewrite_load_or_store(BytecodeStream *bcs, Bytecodes::Code bcN, Bytecodes::Code bc0, unsigned int varNo) {
  assert(bcN == Bytecodes::_astore   || bcN == Bytecodes::_aload,   "wrong argument (bcN)");
  assert(bc0 == Bytecodes::_astore_0 || bc0 == Bytecodes::_aload_0, "wrong argument (bc0)");
  int ilen = Bytecodes::length_at(bcs->bcp());
  int newIlen;

  if (ilen == 4) {
    // Original instruction was wide; keep it wide for simplicity
    newIlen = 4;
  } else if (varNo < 4)
     newIlen = 1;
  else if (varNo >= 256)
     newIlen = 4;
  else
     newIlen = 2;

  // If we need to relocate in order to patch the byte, we
  // do the patching in a temp. buffer, that is passed to the reloc.
  // The patching of the bytecode stream is then done by the Relocator.
  // This is neccesary, since relocating the instruction at a certain bci, might
  // also relocate that instruction, e.g., if a _goto before it gets widen to a _goto_w.
  // Hence, we do not know which bci to patch after relocation.

  assert(newIlen <= 4, "sanity check");
  u_char inst_buffer[4]; // Max. instruction size is 4.
  address bcp;

  if (newIlen != ilen) {
    // Relocation needed do patching in temp. buffer
    bcp = (address)inst_buffer;
  } else {
    bcp = _method->bcp_from(bcs->bci());
  }

  // Patch either directly in methodOop or in temp. buffer
  if (newIlen == 1) {
    assert(varNo < 4, "varNo too large");
    *bcp = bc0 + varNo;
  } else if (newIlen == 2) {
    assert(varNo < 256, "2-byte index needed!");
    *(bcp + 0) = bcN;
    *(bcp + 1) = varNo;
  } else {
    assert(newIlen == 4, "Wrong instruction length");
    *(bcp + 0) = Bytecodes::_wide;
    *(bcp + 1) = bcN;
    Bytes::put_Java_u2(bcp+2, varNo);
  }

  if (newIlen != ilen) {
    expand_current_instr(bcs->bci(), ilen, newIlen, inst_buffer);
  }


  return (newIlen != ilen);
}

class RelocCallback : public RelocatorListener {
 private:
  GenerateOopMap* _gom;
 public:
   RelocCallback(GenerateOopMap* gom) { _gom = gom; };

  // Callback method
  virtual void relocated(int bci, int delta, int new_code_length) {
    _gom->update_basic_blocks  (bci, delta, new_code_length);
    _gom->update_ret_adr_at_TOS(bci, delta);
    _gom->_rt.update_ret_table (bci, delta);
  }
};

// Returns true if expanding was succesful. Otherwise, reports an error and
// returns false.
void GenerateOopMap::expand_current_instr(int bci, int ilen, int newIlen, u_char inst_buffer[]) {
  Thread *THREAD = Thread::current();  // Could really have TRAPS argument.
  RelocCallback rcb(this);
  Relocator rc(_method, &rcb);
  methodHandle m= rc.insert_space_at(bci, newIlen, inst_buffer, THREAD);
  if (m.is_null() || HAS_PENDING_EXCEPTION) {
    report_error("could not rewrite method - exception occurred or bytecode buffer overflow");
    return;
  }

  // Relocator returns a new method oop.
  _did_relocation = true;
  _method = m;
}


bool GenerateOopMap::is_astore(BytecodeStream *itr, int *index) {
  Bytecodes::Code bc = itr->code();
  switch(bc) {
    case Bytecodes::_astore_0:
    case Bytecodes::_astore_1:
    case Bytecodes::_astore_2:
    case Bytecodes::_astore_3:
      *index = bc - Bytecodes::_astore_0;
      return true;
    case Bytecodes::_astore:
      *index = itr->get_index();
      return true;
  }
  return false;
}

bool GenerateOopMap::is_aload(BytecodeStream *itr, int *index) {
  Bytecodes::Code bc = itr->code();
  switch(bc) {
    case Bytecodes::_aload_0:
    case Bytecodes::_aload_1:
    case Bytecodes::_aload_2:
    case Bytecodes::_aload_3:
      *index = bc - Bytecodes::_aload_0;
      return true;

    case Bytecodes::_aload:
      *index = itr->get_index();
      return true;
  }
  return false;
}


// Return true iff the top of the operand stack holds a return address at
// the current instruction
bool GenerateOopMap::stack_top_holds_ret_addr(int bci) {
  for(int i = 0; i < _ret_adr_tos->length(); i++) {
    if (_ret_adr_tos->at(i) == bci)
      return true;
  }

  return false;
}

void GenerateOopMap::compute_ret_adr_at_TOS() {
  assert(_ret_adr_tos != NULL, "must be initialized");
  _ret_adr_tos->clear();

  for (int i = 0; i < bb_count(); i++) {
    BasicBlock* bb = &_basic_blocks[i];

    // Make sure to only check basicblocks that are reachable
    if (bb->is_reachable()) {

      // For each Basic block we check all instructions
      BytecodeStream bcs(_method);
      bcs.set_interval(bb->_bci, next_bb_start_pc(bb));

      restore_state(bb);

      while (bcs.next()>=0 && !_got_error) {
        // TDT: should this be is_good_address() ?
        if (_stack_top > 0 && stack()[_stack_top-1].is_address()) {
          _ret_adr_tos->append(bcs.bci());
          if (TraceNewOopMapGeneration) {
            tty->print_cr("Ret_adr TOS at bci: %d", bcs.bci());
          }
        }
        interp1(&bcs);
      }
    }
  }
}

void GenerateOopMap::update_ret_adr_at_TOS(int bci, int delta) {
  for(int i = 0; i < _ret_adr_tos->length(); i++) {
    int v = _ret_adr_tos->at(i);
    if (v > bci)  _ret_adr_tos->at_put(i, v + delta);
  }
}

// ===================================================================

#ifndef PRODUCT
int ResolveOopMapConflicts::_nof_invocations  = 0;
int ResolveOopMapConflicts::_nof_rewrites     = 0;
int ResolveOopMapConflicts::_nof_relocations  = 0;
#endif

methodHandle ResolveOopMapConflicts::do_potential_rewrite(TRAPS) {
  compute_map(CHECK_(methodHandle()));

#ifndef PRODUCT
  // Tracking and statistics
  if (PrintRewrites) {
    _nof_invocations++;
    if (did_rewriting()) {
      _nof_rewrites++;
      if (did_relocation()) _nof_relocations++;
      tty->print("Method was rewritten %s: ", (did_relocation()) ? "and relocated" : "");
      method()->print_value(); tty->cr();
      tty->print_cr("Cand.: %d rewrts: %d (%d%%) reloc.: %d (%d%%)",
          _nof_invocations,
          _nof_rewrites,    (_nof_rewrites    * 100) / _nof_invocations,
          _nof_relocations, (_nof_relocations * 100) / _nof_invocations);
    }
  }
#endif
  return methodHandle(THREAD, method());
}