Java example source code file (relocInfo.cpp)

This example Java source code file (relocInfo.cpp) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

assert, bytesperint, codebuffer, codebuffer::sect_none, codebuffer\:\:sect_limit, codesection, intptr_format, metadata, null, relocation, relocindexentry, relocindexentry\*, relociterator, shouldnotreachhere

The relocInfo.cpp Java example source code

/*
 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
 * 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.
 *
 * 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.
 *
 */

#include "precompiled.hpp"
#include "code/codeCache.hpp"
#include "code/compiledIC.hpp"
#include "code/nmethod.hpp"
#include "code/relocInfo.hpp"
#include "memory/resourceArea.hpp"
#include "runtime/stubCodeGenerator.hpp"
#include "utilities/copy.hpp"


const RelocationHolder RelocationHolder::none; // its type is relocInfo::none


// Implementation of relocInfo

#ifdef ASSERT
relocInfo::relocInfo(relocType t, int off, int f) {
  assert(t != data_prefix_tag, "cannot build a prefix this way");
  assert((t & type_mask) == t, "wrong type");
  assert((f & format_mask) == f, "wrong format");
  assert(off >= 0 && off < offset_limit(), "offset out off bounds");
  assert((off & (offset_unit-1)) == 0, "misaligned offset");
  (*this) = relocInfo(t, RAW_BITS, off, f);
}
#endif

void relocInfo::initialize(CodeSection* dest, Relocation* reloc) {
  relocInfo* data = this+1;  // here's where the data might go
  dest->set_locs_end(data);  // sync end: the next call may read dest.locs_end
  reloc->pack_data_to(dest); // maybe write data into locs, advancing locs_end
  relocInfo* data_limit = dest->locs_end();
  if (data_limit > data) {
    relocInfo suffix = (*this);
    data_limit = this->finish_prefix((short*) data_limit);
    // Finish up with the suffix.  (Hack note: pack_data_to might edit this.)
    *data_limit = suffix;
    dest->set_locs_end(data_limit+1);
  }
}

relocInfo* relocInfo::finish_prefix(short* prefix_limit) {
  assert(sizeof(relocInfo) == sizeof(short), "change this code");
  short* p = (short*)(this+1);
  assert(prefix_limit >= p, "must be a valid span of data");
  int plen = prefix_limit - p;
  if (plen == 0) {
    debug_only(_value = 0xFFFF);
    return this;                         // no data: remove self completely
  }
  if (plen == 1 && fits_into_immediate(p[0])) {
    (*this) = immediate_relocInfo(p[0]); // move data inside self
    return this+1;
  }
  // cannot compact, so just update the count and return the limit pointer
  (*this) = prefix_relocInfo(plen);   // write new datalen
  assert(data() + datalen() == prefix_limit, "pointers must line up");
  return (relocInfo*)prefix_limit;
}


void relocInfo::set_type(relocType t) {
  int old_offset = addr_offset();
  int old_format = format();
  (*this) = relocInfo(t, old_offset, old_format);
  assert(type()==(int)t, "sanity check");
  assert(addr_offset()==old_offset, "sanity check");
  assert(format()==old_format, "sanity check");
}


void relocInfo::set_format(int f) {
  int old_offset = addr_offset();
  assert((f & format_mask) == f, "wrong format");
  _value = (_value & ~(format_mask << offset_width)) | (f << offset_width);
  assert(addr_offset()==old_offset, "sanity check");
}


void relocInfo::change_reloc_info_for_address(RelocIterator *itr, address pc, relocType old_type, relocType new_type) {
  bool found = false;
  while (itr->next() && !found) {
    if (itr->addr() == pc) {
      assert(itr->type()==old_type, "wrong relocInfo type found");
      itr->current()->set_type(new_type);
      found=true;
    }
  }
  assert(found, "no relocInfo found for pc");
}


void relocInfo::remove_reloc_info_for_address(RelocIterator *itr, address pc, relocType old_type) {
  change_reloc_info_for_address(itr, pc, old_type, none);
}


// ----------------------------------------------------------------------------------------------------
// Implementation of RelocIterator

void RelocIterator::initialize(nmethod* nm, address begin, address limit) {
  initialize_misc();

  if (nm == NULL && begin != NULL) {
    // allow nmethod to be deduced from beginning address
    CodeBlob* cb = CodeCache::find_blob(begin);
    nm = cb->as_nmethod_or_null();
  }
  assert(nm != NULL, "must be able to deduce nmethod from other arguments");

  _code    = nm;
  _current = nm->relocation_begin() - 1;
  _end     = nm->relocation_end();
  _addr    = nm->content_begin();

  // Initialize code sections.
  _section_start[CodeBuffer::SECT_CONSTS] = nm->consts_begin();
  _section_start[CodeBuffer::SECT_INSTS ] = nm->insts_begin() ;
  _section_start[CodeBuffer::SECT_STUBS ] = nm->stub_begin()  ;

  _section_end  [CodeBuffer::SECT_CONSTS] = nm->consts_end()  ;
  _section_end  [CodeBuffer::SECT_INSTS ] = nm->insts_end()   ;
  _section_end  [CodeBuffer::SECT_STUBS ] = nm->stub_end()    ;

  assert(!has_current(), "just checking");
  assert(begin == NULL || begin >= nm->code_begin(), "in bounds");
  assert(limit == NULL || limit <= nm->code_end(),   "in bounds");
  set_limits(begin, limit);
}


RelocIterator::RelocIterator(CodeSection* cs, address begin, address limit) {
  initialize_misc();

  _current = cs->locs_start()-1;
  _end     = cs->locs_end();
  _addr    = cs->start();
  _code    = NULL; // Not cb->blob();

  CodeBuffer* cb = cs->outer();
  assert((int) SECT_LIMIT == CodeBuffer::SECT_LIMIT, "my copy must be equal");
  for (int n = (int) CodeBuffer::SECT_FIRST; n < (int) CodeBuffer::SECT_LIMIT; n++) {
    CodeSection* cs = cb->code_section(n);
    _section_start[n] = cs->start();
    _section_end  [n] = cs->end();
  }

  assert(!has_current(), "just checking");

  assert(begin == NULL || begin >= cs->start(), "in bounds");
  assert(limit == NULL || limit <= cs->end(),   "in bounds");
  set_limits(begin, limit);
}


enum { indexCardSize = 128 };
struct RelocIndexEntry {
  jint addr_offset;          // offset from header_end of an addr()
  jint reloc_offset;         // offset from header_end of a relocInfo (prefix)
};


bool RelocIterator::addr_in_const() const {
  const int n = CodeBuffer::SECT_CONSTS;
  return section_start(n) <= addr() && addr() < section_end(n);
}


static inline int num_cards(int code_size) {
  return (code_size-1) / indexCardSize;
}


int RelocIterator::locs_and_index_size(int code_size, int locs_size) {
  if (!UseRelocIndex)  return locs_size;   // no index
  code_size = round_to(code_size, oopSize);
  locs_size = round_to(locs_size, oopSize);
  int index_size = num_cards(code_size) * sizeof(RelocIndexEntry);
  // format of indexed relocs:
  //   relocation_begin:   relocInfo ...
  //   index:              (addr,reloc#) ...
  //                       indexSize           :relocation_end
  return locs_size + index_size + BytesPerInt;
}


void RelocIterator::create_index(relocInfo* dest_begin, int dest_count, relocInfo* dest_end) {
  address relocation_begin = (address)dest_begin;
  address relocation_end   = (address)dest_end;
  int     total_size       = relocation_end - relocation_begin;
  int     locs_size        = dest_count * sizeof(relocInfo);
  if (!UseRelocIndex) {
    Copy::fill_to_bytes(relocation_begin + locs_size, total_size-locs_size, 0);
    return;
  }
  int     index_size       = total_size - locs_size - BytesPerInt;      // find out how much space is left
  int     ncards           = index_size / sizeof(RelocIndexEntry);
  assert(total_size == locs_size + index_size + BytesPerInt, "checkin'");
  assert(index_size >= 0 && index_size % sizeof(RelocIndexEntry) == 0, "checkin'");
  jint*   index_size_addr  = (jint*)relocation_end - 1;

  assert(sizeof(jint) == BytesPerInt, "change this code");

  *index_size_addr = index_size;
  if (index_size != 0) {
    assert(index_size > 0, "checkin'");

    RelocIndexEntry* index = (RelocIndexEntry *)(relocation_begin + locs_size);
    assert(index == (RelocIndexEntry*)index_size_addr - ncards, "checkin'");

    // walk over the relocations, and fill in index entries as we go
    RelocIterator iter;
    const address    initial_addr    = NULL;
    relocInfo* const initial_current = dest_begin - 1;  // biased by -1 like elsewhere

    iter._code    = NULL;
    iter._addr    = initial_addr;
    iter._limit   = (address)(intptr_t)(ncards * indexCardSize);
    iter._current = initial_current;
    iter._end     = dest_begin + dest_count;

    int i = 0;
    address next_card_addr = (address)indexCardSize;
    int addr_offset = 0;
    int reloc_offset = 0;
    while (true) {
      // Checkpoint the iterator before advancing it.
      addr_offset  = iter._addr    - initial_addr;
      reloc_offset = iter._current - initial_current;
      if (!iter.next())  break;
      while (iter.addr() >= next_card_addr) {
        index[i].addr_offset  = addr_offset;
        index[i].reloc_offset = reloc_offset;
        i++;
        next_card_addr += indexCardSize;
      }
    }
    while (i < ncards) {
      index[i].addr_offset  = addr_offset;
      index[i].reloc_offset = reloc_offset;
      i++;
    }
  }
}


void RelocIterator::set_limits(address begin, address limit) {
  int index_size = 0;
  if (UseRelocIndex && _code != NULL) {
    index_size = ((jint*)_end)[-1];
    _end = (relocInfo*)( (address)_end - index_size - BytesPerInt );
  }

  _limit = limit;

  // the limit affects this next stuff:
  if (begin != NULL) {
#ifdef ASSERT
    // In ASSERT mode we do not actually use the index, but simply
    // check that its contents would have led us to the right answer.
    address addrCheck = _addr;
    relocInfo* infoCheck = _current;
#endif // ASSERT
    if (index_size > 0) {
      // skip ahead
      RelocIndexEntry* index       = (RelocIndexEntry*)_end;
      RelocIndexEntry* index_limit = (RelocIndexEntry*)((address)index + index_size);
      assert(_addr == _code->code_begin(), "_addr must be unadjusted");
      int card = (begin - _addr) / indexCardSize;
      if (card > 0) {
        if (index+card-1 < index_limit)  index += card-1;
        else                             index = index_limit - 1;
#ifdef ASSERT
        addrCheck = _addr    + index->addr_offset;
        infoCheck = _current + index->reloc_offset;
#else
        // Advance the iterator immediately to the last valid state
        // for the previous card.  Calling "next" will then advance
        // it to the first item on the required card.
        _addr    += index->addr_offset;
        _current += index->reloc_offset;
#endif // ASSERT
      }
    }

    relocInfo* backup;
    address    backup_addr;
    while (true) {
      backup      = _current;
      backup_addr = _addr;
#ifdef ASSERT
      if (backup == infoCheck) {
        assert(backup_addr == addrCheck, "must match"); addrCheck = NULL; infoCheck = NULL;
      } else {
        assert(addrCheck == NULL || backup_addr <= addrCheck, "must not pass addrCheck");
      }
#endif // ASSERT
      if (!next() || addr() >= begin) break;
    }
    assert(addrCheck == NULL || addrCheck == backup_addr, "must have matched addrCheck");
    assert(infoCheck == NULL || infoCheck == backup,      "must have matched infoCheck");
    // At this point, either we are at the first matching record,
    // or else there is no such record, and !has_current().
    // In either case, revert to the immediatly preceding state.
    _current = backup;
    _addr    = backup_addr;
    set_has_current(false);
  }
}


void RelocIterator::set_limit(address limit) {
  address code_end = (address)code() + code()->size();
  assert(limit == NULL || limit <= code_end, "in bounds");
  _limit = limit;
}

// All the strange bit-encodings are in here.
// The idea is to encode relocation data which are small integers
// very efficiently (a single extra halfword).  Larger chunks of
// relocation data need a halfword header to hold their size.
void RelocIterator::advance_over_prefix() {
  if (_current->is_datalen()) {
    _data    = (short*) _current->data();
    _datalen =          _current->datalen();
    _current += _datalen + 1;   // skip the embedded data & header
  } else {
    _databuf = _current->immediate();
    _data = &_databuf;
    _datalen = 1;
    _current++;                 // skip the header
  }
  // The client will see the following relocInfo, whatever that is.
  // It is the reloc to which the preceding data applies.
}


void RelocIterator::initialize_misc() {
  set_has_current(false);
  for (int i = (int) CodeBuffer::SECT_FIRST; i < (int) CodeBuffer::SECT_LIMIT; i++) {
    _section_start[i] = NULL;  // these will be lazily computed, if needed
    _section_end  [i] = NULL;
  }
}


Relocation* RelocIterator::reloc() {
  // (take the "switch" out-of-line)
  relocInfo::relocType t = type();
  if (false) {}
  #define EACH_TYPE(name)                             \
  else if (t == relocInfo::name##_type) {             \
    return name##_reloc();                            \
  }
  APPLY_TO_RELOCATIONS(EACH_TYPE);
  #undef EACH_TYPE
  assert(t == relocInfo::none, "must be padding");
  return new(_rh) Relocation();
}


//////// Methods for flyweight Relocation types


RelocationHolder RelocationHolder::plus(int offset) const {
  if (offset != 0) {
    switch (type()) {
    case relocInfo::none:
      break;
    case relocInfo::oop_type:
      {
        oop_Relocation* r = (oop_Relocation*)reloc();
        return oop_Relocation::spec(r->oop_index(), r->offset() + offset);
      }
    case relocInfo::metadata_type:
      {
        metadata_Relocation* r = (metadata_Relocation*)reloc();
        return metadata_Relocation::spec(r->metadata_index(), r->offset() + offset);
      }
    default:
      ShouldNotReachHere();
    }
  }
  return (*this);
}


void Relocation::guarantee_size() {
  guarantee(false, "Make _relocbuf bigger!");
}

    // some relocations can compute their own values
address Relocation::value() {
  ShouldNotReachHere();
  return NULL;
}


void Relocation::set_value(address x) {
  ShouldNotReachHere();
}


RelocationHolder Relocation::spec_simple(relocInfo::relocType rtype) {
  if (rtype == relocInfo::none)  return RelocationHolder::none;
  relocInfo ri = relocInfo(rtype, 0);
  RelocIterator itr;
  itr.set_current(ri);
  itr.reloc();
  return itr._rh;
}

int32_t Relocation::runtime_address_to_index(address runtime_address) {
  assert(!is_reloc_index((intptr_t)runtime_address), "must not look like an index");

  if (runtime_address == NULL)  return 0;

  StubCodeDesc* p = StubCodeDesc::desc_for(runtime_address);
  if (p != NULL && p->begin() == runtime_address) {
    assert(is_reloc_index(p->index()), "there must not be too many stubs");
    return (int32_t)p->index();
  } else {
    // Known "miscellaneous" non-stub pointers:
    // os::get_polling_page(), SafepointSynchronize::address_of_state()
    if (PrintRelocations) {
      tty->print_cr("random unregistered address in relocInfo: " INTPTR_FORMAT, runtime_address);
    }
#ifndef _LP64
    return (int32_t) (intptr_t)runtime_address;
#else
    // didn't fit return non-index
    return -1;
#endif /* _LP64 */
  }
}


address Relocation::index_to_runtime_address(int32_t index) {
  if (index == 0)  return NULL;

  if (is_reloc_index(index)) {
    StubCodeDesc* p = StubCodeDesc::desc_for_index(index);
    assert(p != NULL, "there must be a stub for this index");
    return p->begin();
  } else {
#ifndef _LP64
    // this only works on 32bit machines
    return (address) ((intptr_t) index);
#else
    fatal("Relocation::index_to_runtime_address, int32_t not pointer sized");
    return NULL;
#endif /* _LP64 */
  }
}

address Relocation::old_addr_for(address newa,
                                 const CodeBuffer* src, CodeBuffer* dest) {
  int sect = dest->section_index_of(newa);
  guarantee(sect != CodeBuffer::SECT_NONE, "lost track of this address");
  address ostart = src->code_section(sect)->start();
  address nstart = dest->code_section(sect)->start();
  return ostart + (newa - nstart);
}

address Relocation::new_addr_for(address olda,
                                 const CodeBuffer* src, CodeBuffer* dest) {
  debug_only(const CodeBuffer* src0 = src);
  int sect = CodeBuffer::SECT_NONE;
  // Look for olda in the source buffer, and all previous incarnations
  // if the source buffer has been expanded.
  for (; src != NULL; src = src->before_expand()) {
    sect = src->section_index_of(olda);
    if (sect != CodeBuffer::SECT_NONE)  break;
  }
  guarantee(sect != CodeBuffer::SECT_NONE, "lost track of this address");
  address ostart = src->code_section(sect)->start();
  address nstart = dest->code_section(sect)->start();
  return nstart + (olda - ostart);
}

void Relocation::normalize_address(address& addr, const CodeSection* dest, bool allow_other_sections) {
  address addr0 = addr;
  if (addr0 == NULL || dest->allocates2(addr0))  return;
  CodeBuffer* cb = dest->outer();
  addr = new_addr_for(addr0, cb, cb);
  assert(allow_other_sections || dest->contains2(addr),
         "addr must be in required section");
}


void CallRelocation::set_destination(address x) {
  pd_set_call_destination(x);
}

void CallRelocation::fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) {
  // Usually a self-relative reference to an external routine.
  // On some platforms, the reference is absolute (not self-relative).
  // The enhanced use of pd_call_destination sorts this all out.
  address orig_addr = old_addr_for(addr(), src, dest);
  address callee    = pd_call_destination(orig_addr);
  // Reassert the callee address, this time in the new copy of the code.
  pd_set_call_destination(callee);
}


//// pack/unpack methods

void oop_Relocation::pack_data_to(CodeSection* dest) {
  short* p = (short*) dest->locs_end();
  p = pack_2_ints_to(p, _oop_index, _offset);
  dest->set_locs_end((relocInfo*) p);
}


void oop_Relocation::unpack_data() {
  unpack_2_ints(_oop_index, _offset);
}

void metadata_Relocation::pack_data_to(CodeSection* dest) {
  short* p = (short*) dest->locs_end();
  p = pack_2_ints_to(p, _metadata_index, _offset);
  dest->set_locs_end((relocInfo*) p);
}


void metadata_Relocation::unpack_data() {
  unpack_2_ints(_metadata_index, _offset);
}


void virtual_call_Relocation::pack_data_to(CodeSection* dest) {
  short*  p     = (short*) dest->locs_end();
  address point =          dest->locs_point();

  normalize_address(_cached_value, dest);
  jint x0 = scaled_offset_null_special(_cached_value, point);
  p = pack_1_int_to(p, x0);
  dest->set_locs_end((relocInfo*) p);
}


void virtual_call_Relocation::unpack_data() {
  jint x0 = unpack_1_int();
  address point = addr();
  _cached_value = x0==0? NULL: address_from_scaled_offset(x0, point);
}


void static_stub_Relocation::pack_data_to(CodeSection* dest) {
  short* p = (short*) dest->locs_end();
  CodeSection* insts = dest->outer()->insts();
  normalize_address(_static_call, insts);
  p = pack_1_int_to(p, scaled_offset(_static_call, insts->start()));
  dest->set_locs_end((relocInfo*) p);
}

void static_stub_Relocation::unpack_data() {
  address base = binding()->section_start(CodeBuffer::SECT_INSTS);
  _static_call = address_from_scaled_offset(unpack_1_int(), base);
}


void external_word_Relocation::pack_data_to(CodeSection* dest) {
  short* p = (short*) dest->locs_end();
  int32_t index = runtime_address_to_index(_target);
#ifndef _LP64
  p = pack_1_int_to(p, index);
#else
  if (is_reloc_index(index)) {
    p = pack_2_ints_to(p, index, 0);
  } else {
    jlong t = (jlong) _target;
    int32_t lo = low(t);
    int32_t hi = high(t);
    p = pack_2_ints_to(p, lo, hi);
    DEBUG_ONLY(jlong t1 = jlong_from(hi, lo));
    assert(!is_reloc_index(t1) && (address) t1 == _target, "not symmetric");
  }
#endif /* _LP64 */
  dest->set_locs_end((relocInfo*) p);
}


void external_word_Relocation::unpack_data() {
#ifndef _LP64
  _target = index_to_runtime_address(unpack_1_int());
#else
  int32_t lo, hi;
  unpack_2_ints(lo, hi);
  jlong t = jlong_from(hi, lo);;
  if (is_reloc_index(t)) {
    _target = index_to_runtime_address(t);
  } else {
    _target = (address) t;
  }
#endif /* _LP64 */
}


void internal_word_Relocation::pack_data_to(CodeSection* dest) {
  short* p = (short*) dest->locs_end();
  normalize_address(_target, dest, true);

  // Check whether my target address is valid within this section.
  // If not, strengthen the relocation type to point to another section.
  int sindex = _section;
  if (sindex == CodeBuffer::SECT_NONE && _target != NULL
      && (!dest->allocates(_target) || _target == dest->locs_point())) {
    sindex = dest->outer()->section_index_of(_target);
    guarantee(sindex != CodeBuffer::SECT_NONE, "must belong somewhere");
    relocInfo* base = dest->locs_end() - 1;
    assert(base->type() == this->type(), "sanity");
    // Change the written type, to be section_word_type instead.
    base->set_type(relocInfo::section_word_type);
  }

  // Note: An internal_word relocation cannot refer to its own instruction,
  // because we reserve "0" to mean that the pointer itself is embedded
  // in the code stream.  We use a section_word relocation for such cases.

  if (sindex == CodeBuffer::SECT_NONE) {
    assert(type() == relocInfo::internal_word_type, "must be base class");
    guarantee(_target == NULL || dest->allocates2(_target), "must be within the given code section");
    jint x0 = scaled_offset_null_special(_target, dest->locs_point());
    assert(!(x0 == 0 && _target != NULL), "correct encoding of null target");
    p = pack_1_int_to(p, x0);
  } else {
    assert(_target != NULL, "sanity");
    CodeSection* sect = dest->outer()->code_section(sindex);
    guarantee(sect->allocates2(_target), "must be in correct section");
    address base = sect->start();
    jint offset = scaled_offset(_target, base);
    assert((uint)sindex < (uint)CodeBuffer::SECT_LIMIT, "sanity");
    assert(CodeBuffer::SECT_LIMIT <= (1 << section_width), "section_width++");
    p = pack_1_int_to(p, (offset << section_width) | sindex);
  }

  dest->set_locs_end((relocInfo*) p);
}


void internal_word_Relocation::unpack_data() {
  jint x0 = unpack_1_int();
  _target = x0==0? NULL: address_from_scaled_offset(x0, addr());
  _section = CodeBuffer::SECT_NONE;
}


void section_word_Relocation::unpack_data() {
  jint    x      = unpack_1_int();
  jint    offset = (x >> section_width);
  int     sindex = (x & ((1<format());
  if (datalen() == 1) {
    tty->print(" data=%d", data()[0]);
  } else if (datalen() > 0) {
    tty->print(" data={");
    for (int i = 0; i < datalen(); i++) {
      tty->print("%04x", data()[i] & 0xFFFF);
    }
    tty->print("}");
  }
  tty->print("]");
  switch (type()) {
  case relocInfo::oop_type:
    {
      oop_Relocation* r = oop_reloc();
      oop* oop_addr  = NULL;
      oop  raw_oop   = NULL;
      oop  oop_value = NULL;
      if (code() != NULL || r->oop_is_immediate()) {
        oop_addr  = r->oop_addr();
        raw_oop   = *oop_addr;
        oop_value = r->oop_value();
      }
      tty->print(" | [oop_addr=" INTPTR_FORMAT " *=" INTPTR_FORMAT " offset=%d]",
                 oop_addr, (address)raw_oop, r->offset());
      // Do not print the oop by default--we want this routine to
      // work even during GC or other inconvenient times.
      if (WizardMode && oop_value != NULL) {
        tty->print("oop_value=" INTPTR_FORMAT ": ", (address)oop_value);
        oop_value->print_value_on(tty);
      }
      break;
    }
  case relocInfo::metadata_type:
    {
      metadata_Relocation* r = metadata_reloc();
      Metadata** metadata_addr  = NULL;
      Metadata*    raw_metadata   = NULL;
      Metadata*    metadata_value = NULL;
      if (code() != NULL || r->metadata_is_immediate()) {
        metadata_addr  = r->metadata_addr();
        raw_metadata   = *metadata_addr;
        metadata_value = r->metadata_value();
      }
      tty->print(" | [metadata_addr=" INTPTR_FORMAT " *=" INTPTR_FORMAT " offset=%d]",
                 metadata_addr, (address)raw_metadata, r->offset());
      if (metadata_value != NULL) {
        tty->print("metadata_value=" INTPTR_FORMAT ": ", (address)metadata_value);
        metadata_value->print_value_on(tty);
      }
      break;
    }
  case relocInfo::external_word_type:
  case relocInfo::internal_word_type:
  case relocInfo::section_word_type:
    {
      DataRelocation* r = (DataRelocation*) reloc();
      tty->print(" | [target=" INTPTR_FORMAT "]", r->value()); //value==target
      break;
    }
  case relocInfo::static_call_type:
  case relocInfo::runtime_call_type:
    {
      CallRelocation* r = (CallRelocation*) reloc();
      tty->print(" | [destination=" INTPTR_FORMAT "]", r->destination());
      break;
    }
  case relocInfo::virtual_call_type:
    {
      virtual_call_Relocation* r = (virtual_call_Relocation*) reloc();
      tty->print(" | [destination=" INTPTR_FORMAT " cached_value=" INTPTR_FORMAT "]",
                 r->destination(), r->cached_value());
      break;
    }
  case relocInfo::static_stub_type:
    {
      static_stub_Relocation* r = (static_stub_Relocation*) reloc();
      tty->print(" | [static_call=" INTPTR_FORMAT "]", r->static_call());
      break;
    }
  }
  tty->cr();
}


void RelocIterator::print() {
  RelocIterator save_this = (*this);
  relocInfo* scan = _current;
  if (!has_current())  scan += 1;  // nothing to scan here!

  bool skip_next = has_current();
  bool got_next;
  while (true) {
    got_next = (skip_next || next());
    skip_next = false;

    tty->print("         @" INTPTR_FORMAT ": ", scan);
    relocInfo* newscan = _current+1;
    if (!has_current())  newscan -= 1;  // nothing to scan here!
    while (scan < newscan) {
      tty->print("%04x", *(short*)scan & 0xFFFF);
      scan++;
    }
    tty->cr();

    if (!got_next)  break;
    print_current();
  }

  (*this) = save_this;
}

// For the debugger:
extern "C"
void print_blob_locs(nmethod* nm) {
  nm->print();
  RelocIterator iter(nm);
  iter.print();
}
extern "C"
void print_buf_locs(CodeBuffer* cb) {
  FlagSetting fs(PrintRelocations, true);
  cb->print();
}
#endif // !PRODUCT