1 /*
   2  * Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "code/codeCache.hpp"
  27 #include "code/compiledIC.hpp"
  28 #include "code/nmethod.hpp"
  29 #include "code/relocInfo.hpp"
  30 #include "memory/resourceArea.hpp"
  31 #include "runtime/stubCodeGenerator.hpp"
  32 #include "utilities/copy.hpp"
  33 #include "oops/oop.inline.hpp"
  34 
  35 const RelocationHolder RelocationHolder::none; // its type is relocInfo::none
  36 
  37 
  38 // Implementation of relocInfo
  39 
  40 #ifdef ASSERT
  41 relocInfo::relocInfo(relocType t, int off, int f) {
  42   assert(t != data_prefix_tag, "cannot build a prefix this way");
  43   assert((t & type_mask) == t, "wrong type");
  44   assert((f & format_mask) == f, "wrong format");
  45   assert(off >= 0 && off < offset_limit(), "offset out off bounds");
  46   assert((off & (offset_unit-1)) == 0, "misaligned offset");
  47   (*this) = relocInfo(t, RAW_BITS, off, f);
  48 }
  49 #endif
  50 
  51 void relocInfo::initialize(CodeSection* dest, Relocation* reloc) {
  52   relocInfo* data = this+1;  // here's where the data might go
  53   dest->set_locs_end(data);  // sync end: the next call may read dest.locs_end
  54   reloc->pack_data_to(dest); // maybe write data into locs, advancing locs_end
  55   relocInfo* data_limit = dest->locs_end();
  56   if (data_limit > data) {
  57     relocInfo suffix = (*this);
  58     data_limit = this->finish_prefix((short*) data_limit);
  59     // Finish up with the suffix.  (Hack note: pack_data_to might edit this.)
  60     *data_limit = suffix;
  61     dest->set_locs_end(data_limit+1);
  62   }
  63 }
  64 
  65 relocInfo* relocInfo::finish_prefix(short* prefix_limit) {
  66   assert(sizeof(relocInfo) == sizeof(short), "change this code");
  67   short* p = (short*)(this+1);
  68   assert(prefix_limit >= p, "must be a valid span of data");
  69   int plen = prefix_limit - p;
  70   if (plen == 0) {
  71     debug_only(_value = 0xFFFF);
  72     return this;                         // no data: remove self completely
  73   }
  74   if (plen == 1 && fits_into_immediate(p[0])) {
  75     (*this) = immediate_relocInfo(p[0]); // move data inside self
  76     return this+1;
  77   }
  78   // cannot compact, so just update the count and return the limit pointer
  79   (*this) = prefix_relocInfo(plen);   // write new datalen
  80   assert(data() + datalen() == prefix_limit, "pointers must line up");
  81   return (relocInfo*)prefix_limit;
  82 }
  83 
  84 void relocInfo::set_type(relocType t) {
  85   int old_offset = addr_offset();
  86   int old_format = format();
  87   (*this) = relocInfo(t, old_offset, old_format);
  88   assert(type()==(int)t, "sanity check");
  89   assert(addr_offset()==old_offset, "sanity check");
  90   assert(format()==old_format, "sanity check");
  91 }
  92 
  93 nmethod* RelocIterator::code_as_nmethod() const {
  94   return _code->as_nmethod();
  95 }
  96 
  97 void relocInfo::set_format(int f) {
  98   int old_offset = addr_offset();
  99   assert((f & format_mask) == f, "wrong format");
 100   _value = (_value & ~(format_mask << offset_width)) | (f << offset_width);
 101   assert(addr_offset()==old_offset, "sanity check");
 102 }
 103 
 104 
 105 void relocInfo::change_reloc_info_for_address(RelocIterator *itr, address pc, relocType old_type, relocType new_type) {
 106   bool found = false;
 107   while (itr->next() && !found) {
 108     if (itr->addr() == pc) {
 109       assert(itr->type()==old_type, "wrong relocInfo type found");
 110       itr->current()->set_type(new_type);
 111       found=true;
 112     }
 113   }
 114   assert(found, "no relocInfo found for pc");
 115 }
 116 
 117 
 118 void relocInfo::remove_reloc_info_for_address(RelocIterator *itr, address pc, relocType old_type) {
 119   change_reloc_info_for_address(itr, pc, old_type, none);
 120 }
 121 
 122 
 123 // ----------------------------------------------------------------------------------------------------
 124 // Implementation of RelocIterator
 125 
 126 void RelocIterator::initialize(CompiledMethod* nm, address begin, address limit) {
 127   initialize_misc();
 128 
 129   if (nm == NULL && begin != NULL) {
 130     // allow nmethod to be deduced from beginning address
 131     CodeBlob* cb = CodeCache::find_blob(begin);
 132     nm = cb->as_compiled_method_or_null();
 133   }
 134   assert(nm != NULL, "must be able to deduce nmethod from other arguments");
 135 
 136   _code    = nm;
 137   _current = nm->relocation_begin() - 1;
 138   _end     = nm->relocation_end();
 139   _addr    = nm->content_begin();
 140 
 141   // Initialize code sections.
 142   _section_start[CodeBuffer::SECT_CONSTS] = nm->consts_begin();
 143   _section_start[CodeBuffer::SECT_INSTS ] = nm->insts_begin() ;
 144   _section_start[CodeBuffer::SECT_STUBS ] = nm->stub_begin()  ;
 145 
 146   _section_end  [CodeBuffer::SECT_CONSTS] = nm->consts_end()  ;
 147   _section_end  [CodeBuffer::SECT_INSTS ] = nm->insts_end()   ;
 148   _section_end  [CodeBuffer::SECT_STUBS ] = nm->stub_end()    ;
 149 
 150   assert(!has_current(), "just checking");
 151   assert(begin == NULL || begin >= nm->code_begin(), "in bounds");
 152   assert(limit == NULL || limit <= nm->code_end(),   "in bounds");
 153   set_limits(begin, limit);
 154 }
 155 
 156 
 157 RelocIterator::RelocIterator(CodeSection* cs, address begin, address limit) {
 158   initialize_misc();
 159 
 160   _current = cs->locs_start()-1;
 161   _end     = cs->locs_end();
 162   _addr    = cs->start();
 163   _code    = NULL; // Not cb->blob();
 164 
 165   CodeBuffer* cb = cs->outer();
 166   assert((int) SECT_LIMIT == CodeBuffer::SECT_LIMIT, "my copy must be equal");
 167   for (int n = (int) CodeBuffer::SECT_FIRST; n < (int) CodeBuffer::SECT_LIMIT; n++) {
 168     CodeSection* cs = cb->code_section(n);
 169     _section_start[n] = cs->start();
 170     _section_end  [n] = cs->end();
 171   }
 172 
 173   assert(!has_current(), "just checking");
 174 
 175   assert(begin == NULL || begin >= cs->start(), "in bounds");
 176   assert(limit == NULL || limit <= cs->end(),   "in bounds");
 177   set_limits(begin, limit);
 178 }
 179 
 180 
 181 enum { indexCardSize = 128 };
 182 struct RelocIndexEntry {
 183   jint addr_offset;          // offset from header_end of an addr()
 184   jint reloc_offset;         // offset from header_end of a relocInfo (prefix)
 185 };
 186 
 187 
 188 bool RelocIterator::addr_in_const() const {
 189   const int n = CodeBuffer::SECT_CONSTS;
 190   return section_start(n) <= addr() && addr() < section_end(n);
 191 }
 192 
 193 
 194 static inline int num_cards(int code_size) {
 195   return (code_size-1) / indexCardSize;
 196 }
 197 
 198 
 199 int RelocIterator::locs_and_index_size(int code_size, int locs_size) {
 200   if (!UseRelocIndex)  return locs_size;   // no index
 201   code_size = round_to(code_size, oopSize);
 202   locs_size = round_to(locs_size, oopSize);
 203   int index_size = num_cards(code_size) * sizeof(RelocIndexEntry);
 204   // format of indexed relocs:
 205   //   relocation_begin:   relocInfo ...
 206   //   index:              (addr,reloc#) ...
 207   //                       indexSize           :relocation_end
 208   return locs_size + index_size + BytesPerInt;
 209 }
 210 
 211 
 212 void RelocIterator::create_index(relocInfo* dest_begin, int dest_count, relocInfo* dest_end) {
 213   address relocation_begin = (address)dest_begin;
 214   address relocation_end   = (address)dest_end;
 215   int     total_size       = relocation_end - relocation_begin;
 216   int     locs_size        = dest_count * sizeof(relocInfo);
 217   if (!UseRelocIndex) {
 218     Copy::fill_to_bytes(relocation_begin + locs_size, total_size-locs_size, 0);
 219     return;
 220   }
 221   int     index_size       = total_size - locs_size - BytesPerInt;      // find out how much space is left
 222   int     ncards           = index_size / sizeof(RelocIndexEntry);
 223   assert(total_size == locs_size + index_size + BytesPerInt, "checkin'");
 224   assert(index_size >= 0 && index_size % sizeof(RelocIndexEntry) == 0, "checkin'");
 225   jint*   index_size_addr  = (jint*)relocation_end - 1;
 226 
 227   assert(sizeof(jint) == BytesPerInt, "change this code");
 228 
 229   *index_size_addr = index_size;
 230   if (index_size != 0) {
 231     assert(index_size > 0, "checkin'");
 232 
 233     RelocIndexEntry* index = (RelocIndexEntry *)(relocation_begin + locs_size);
 234     assert(index == (RelocIndexEntry*)index_size_addr - ncards, "checkin'");
 235 
 236     // walk over the relocations, and fill in index entries as we go
 237     RelocIterator iter;
 238     const address    initial_addr    = NULL;
 239     relocInfo* const initial_current = dest_begin - 1;  // biased by -1 like elsewhere
 240 
 241     iter._code    = NULL;
 242     iter._addr    = initial_addr;
 243     iter._limit   = (address)(intptr_t)(ncards * indexCardSize);
 244     iter._current = initial_current;
 245     iter._end     = dest_begin + dest_count;
 246 
 247     int i = 0;
 248     address next_card_addr = (address)indexCardSize;
 249     int addr_offset = 0;
 250     int reloc_offset = 0;
 251     while (true) {
 252       // Checkpoint the iterator before advancing it.
 253       addr_offset  = iter._addr    - initial_addr;
 254       reloc_offset = iter._current - initial_current;
 255       if (!iter.next())  break;
 256       while (iter.addr() >= next_card_addr) {
 257         index[i].addr_offset  = addr_offset;
 258         index[i].reloc_offset = reloc_offset;
 259         i++;
 260         next_card_addr += indexCardSize;
 261       }
 262     }
 263     while (i < ncards) {
 264       index[i].addr_offset  = addr_offset;
 265       index[i].reloc_offset = reloc_offset;
 266       i++;
 267     }
 268   }
 269 }
 270 
 271 
 272 void RelocIterator::set_limits(address begin, address limit) {
 273   int index_size = 0;
 274   if (UseRelocIndex && _code != NULL) {
 275     index_size = ((jint*)_end)[-1];
 276     _end = (relocInfo*)( (address)_end - index_size - BytesPerInt );
 277   }
 278 
 279   _limit = limit;
 280 
 281   // the limit affects this next stuff:
 282   if (begin != NULL) {
 283 #ifdef ASSERT
 284     // In ASSERT mode we do not actually use the index, but simply
 285     // check that its contents would have led us to the right answer.
 286     address addrCheck = _addr;
 287     relocInfo* infoCheck = _current;
 288 #endif // ASSERT
 289     if (index_size > 0) {
 290       // skip ahead
 291       RelocIndexEntry* index       = (RelocIndexEntry*)_end;
 292       RelocIndexEntry* index_limit = (RelocIndexEntry*)((address)index + index_size);
 293       assert(_addr == _code->code_begin(), "_addr must be unadjusted");
 294       int card = (begin - _addr) / indexCardSize;
 295       if (card > 0) {
 296         if (index+card-1 < index_limit)  index += card-1;
 297         else                             index = index_limit - 1;
 298 #ifdef ASSERT
 299         addrCheck = _addr    + index->addr_offset;
 300         infoCheck = _current + index->reloc_offset;
 301 #else
 302         // Advance the iterator immediately to the last valid state
 303         // for the previous card.  Calling "next" will then advance
 304         // it to the first item on the required card.
 305         _addr    += index->addr_offset;
 306         _current += index->reloc_offset;
 307 #endif // ASSERT
 308       }
 309     }
 310 
 311     relocInfo* backup;
 312     address    backup_addr;
 313     while (true) {
 314       backup      = _current;
 315       backup_addr = _addr;
 316 #ifdef ASSERT
 317       if (backup == infoCheck) {
 318         assert(backup_addr == addrCheck, "must match"); addrCheck = NULL; infoCheck = NULL;
 319       } else {
 320         assert(addrCheck == NULL || backup_addr <= addrCheck, "must not pass addrCheck");
 321       }
 322 #endif // ASSERT
 323       if (!next() || addr() >= begin) break;
 324     }
 325     assert(addrCheck == NULL || addrCheck == backup_addr, "must have matched addrCheck");
 326     assert(infoCheck == NULL || infoCheck == backup,      "must have matched infoCheck");
 327     // At this point, either we are at the first matching record,
 328     // or else there is no such record, and !has_current().
 329     // In either case, revert to the immediatly preceding state.
 330     _current = backup;
 331     _addr    = backup_addr;
 332     set_has_current(false);
 333   }
 334 }
 335 
 336 
 337 void RelocIterator::set_limit(address limit) {
 338   address code_end = (address)code() + code()->size();
 339   assert(limit == NULL || limit <= code_end, "in bounds");
 340   _limit = limit;
 341 }
 342 
 343 // All the strange bit-encodings are in here.
 344 // The idea is to encode relocation data which are small integers
 345 // very efficiently (a single extra halfword).  Larger chunks of
 346 // relocation data need a halfword header to hold their size.
 347 void RelocIterator::advance_over_prefix() {
 348   if (_current->is_datalen()) {
 349     _data    = (short*) _current->data();
 350     _datalen =          _current->datalen();
 351     _current += _datalen + 1;   // skip the embedded data & header
 352   } else {
 353     _databuf = _current->immediate();
 354     _data = &_databuf;
 355     _datalen = 1;
 356     _current++;                 // skip the header
 357   }
 358   // The client will see the following relocInfo, whatever that is.
 359   // It is the reloc to which the preceding data applies.
 360 }
 361 
 362 
 363 void RelocIterator::initialize_misc() {
 364   set_has_current(false);
 365   for (int i = (int) CodeBuffer::SECT_FIRST; i < (int) CodeBuffer::SECT_LIMIT; i++) {
 366     _section_start[i] = NULL;  // these will be lazily computed, if needed
 367     _section_end  [i] = NULL;
 368   }
 369 }
 370 
 371 
 372 Relocation* RelocIterator::reloc() {
 373   // (take the "switch" out-of-line)
 374   relocInfo::relocType t = type();
 375   if (false) {}
 376   #define EACH_TYPE(name)                             \
 377   else if (t == relocInfo::name##_type) {             \
 378     return name##_reloc();                            \
 379   }
 380   APPLY_TO_RELOCATIONS(EACH_TYPE);
 381   #undef EACH_TYPE
 382   assert(t == relocInfo::none, "must be padding");
 383   return new(_rh) Relocation();
 384 }
 385 
 386 
 387 //////// Methods for flyweight Relocation types
 388 
 389 
 390 RelocationHolder RelocationHolder::plus(int offset) const {
 391   if (offset != 0) {
 392     switch (type()) {
 393     case relocInfo::none:
 394       break;
 395     case relocInfo::oop_type:
 396       {
 397         oop_Relocation* r = (oop_Relocation*)reloc();
 398         return oop_Relocation::spec(r->oop_index(), r->offset() + offset);
 399       }
 400     case relocInfo::metadata_type:
 401       {
 402         metadata_Relocation* r = (metadata_Relocation*)reloc();
 403         return metadata_Relocation::spec(r->metadata_index(), r->offset() + offset);
 404       }
 405     default:
 406       ShouldNotReachHere();
 407     }
 408   }
 409   return (*this);
 410 }
 411 
 412 
 413 void Relocation::guarantee_size() {
 414   guarantee(false, "Make _relocbuf bigger!");
 415 }
 416 
 417     // some relocations can compute their own values
 418 address Relocation::value() {
 419   ShouldNotReachHere();
 420   return NULL;
 421 }
 422 
 423 
 424 void Relocation::set_value(address x) {
 425   ShouldNotReachHere();
 426 }
 427 
 428 void Relocation::const_set_data_value(address x) {
 429 #ifdef _LP64
 430   if (format() == relocInfo::narrow_oop_in_const) {
 431     *(narrowOop*)addr() = oopDesc::encode_heap_oop((oop) x);
 432   } else {
 433 #endif
 434     *(address*)addr() = x;
 435 #ifdef _LP64
 436   }
 437 #endif
 438 }
 439 
 440 void Relocation::const_verify_data_value(address x) {
 441 #ifdef _LP64
 442   if (format() == relocInfo::narrow_oop_in_const) {
 443     guarantee(*(narrowOop*)addr() == oopDesc::encode_heap_oop((oop) x), "must agree");
 444   } else {
 445 #endif
 446     guarantee(*(address*)addr() == x, "must agree");
 447 #ifdef _LP64
 448   }
 449 #endif
 450 }
 451 
 452 
 453 RelocationHolder Relocation::spec_simple(relocInfo::relocType rtype) {
 454   if (rtype == relocInfo::none)  return RelocationHolder::none;
 455   relocInfo ri = relocInfo(rtype, 0);
 456   RelocIterator itr;
 457   itr.set_current(ri);
 458   itr.reloc();
 459   return itr._rh;
 460 }
 461 
 462 address Relocation::old_addr_for(address newa,
 463                                  const CodeBuffer* src, CodeBuffer* dest) {
 464   int sect = dest->section_index_of(newa);
 465   guarantee(sect != CodeBuffer::SECT_NONE, "lost track of this address");
 466   address ostart = src->code_section(sect)->start();
 467   address nstart = dest->code_section(sect)->start();
 468   return ostart + (newa - nstart);
 469 }
 470 
 471 address Relocation::new_addr_for(address olda,
 472                                  const CodeBuffer* src, CodeBuffer* dest) {
 473   debug_only(const CodeBuffer* src0 = src);
 474   int sect = CodeBuffer::SECT_NONE;
 475   // Look for olda in the source buffer, and all previous incarnations
 476   // if the source buffer has been expanded.
 477   for (; src != NULL; src = src->before_expand()) {
 478     sect = src->section_index_of(olda);
 479     if (sect != CodeBuffer::SECT_NONE)  break;
 480   }
 481   guarantee(sect != CodeBuffer::SECT_NONE, "lost track of this address");
 482   address ostart = src->code_section(sect)->start();
 483   address nstart = dest->code_section(sect)->start();
 484   return nstart + (olda - ostart);
 485 }
 486 
 487 void Relocation::normalize_address(address& addr, const CodeSection* dest, bool allow_other_sections) {
 488   address addr0 = addr;
 489   if (addr0 == NULL || dest->allocates2(addr0))  return;
 490   CodeBuffer* cb = dest->outer();
 491   addr = new_addr_for(addr0, cb, cb);
 492   assert(allow_other_sections || dest->contains2(addr),
 493          "addr must be in required section");
 494 }
 495 
 496 
 497 void CallRelocation::set_destination(address x) {
 498   pd_set_call_destination(x);
 499 }
 500 
 501 void CallRelocation::fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) {
 502   // Usually a self-relative reference to an external routine.
 503   // On some platforms, the reference is absolute (not self-relative).
 504   // The enhanced use of pd_call_destination sorts this all out.
 505   address orig_addr = old_addr_for(addr(), src, dest);
 506   address callee    = pd_call_destination(orig_addr);
 507   // Reassert the callee address, this time in the new copy of the code.
 508   pd_set_call_destination(callee);
 509 }
 510 
 511 
 512 //// pack/unpack methods
 513 
 514 void oop_Relocation::pack_data_to(CodeSection* dest) {
 515   short* p = (short*) dest->locs_end();
 516   p = pack_2_ints_to(p, _oop_index, _offset);
 517   dest->set_locs_end((relocInfo*) p);
 518 }
 519 
 520 
 521 void oop_Relocation::unpack_data() {
 522   unpack_2_ints(_oop_index, _offset);
 523 }
 524 
 525 void metadata_Relocation::pack_data_to(CodeSection* dest) {
 526   short* p = (short*) dest->locs_end();
 527   p = pack_2_ints_to(p, _metadata_index, _offset);
 528   dest->set_locs_end((relocInfo*) p);
 529 }
 530 
 531 
 532 void metadata_Relocation::unpack_data() {
 533   unpack_2_ints(_metadata_index, _offset);
 534 }
 535 
 536 
 537 void virtual_call_Relocation::pack_data_to(CodeSection* dest) {
 538   short*  p     = (short*) dest->locs_end();
 539   address point =          dest->locs_point();
 540 
 541   normalize_address(_cached_value, dest);
 542   jint x0 = scaled_offset_null_special(_cached_value, point);
 543   p = pack_2_ints_to(p, x0, _method_index);
 544   dest->set_locs_end((relocInfo*) p);
 545 }
 546 
 547 
 548 void virtual_call_Relocation::unpack_data() {
 549   jint x0 = 0;
 550   unpack_2_ints(x0, _method_index);
 551   address point = addr();
 552   _cached_value = x0==0? NULL: address_from_scaled_offset(x0, point);
 553 }
 554 
 555 void runtime_call_w_cp_Relocation::pack_data_to(CodeSection * dest) {
 556   short* p = pack_1_int_to((short *)dest->locs_end(), (jint)(_offset >> 2));
 557   dest->set_locs_end((relocInfo*) p);
 558 }
 559 
 560 void runtime_call_w_cp_Relocation::unpack_data() {
 561   _offset = unpack_1_int() << 2;
 562 }
 563 
 564 void static_stub_Relocation::pack_data_to(CodeSection* dest) {
 565   short* p = (short*) dest->locs_end();
 566   CodeSection* insts = dest->outer()->insts();
 567   normalize_address(_static_call, insts);
 568   jint is_aot = _is_aot ? 1 : 0;
 569   p = pack_2_ints_to(p, scaled_offset(_static_call, insts->start()), is_aot);
 570   dest->set_locs_end((relocInfo*) p);
 571 }
 572 
 573 void static_stub_Relocation::unpack_data() {
 574   address base = binding()->section_start(CodeBuffer::SECT_INSTS);
 575   jint offset;
 576   jint is_aot;
 577   unpack_2_ints(offset, is_aot);
 578   _static_call = address_from_scaled_offset(offset, base);
 579   _is_aot = (is_aot == 1);
 580 }
 581 
 582 void trampoline_stub_Relocation::pack_data_to(CodeSection* dest ) {
 583   short* p = (short*) dest->locs_end();
 584   CodeSection* insts = dest->outer()->insts();
 585   normalize_address(_owner, insts);
 586   p = pack_1_int_to(p, scaled_offset(_owner, insts->start()));
 587   dest->set_locs_end((relocInfo*) p);
 588 }
 589 
 590 void trampoline_stub_Relocation::unpack_data() {
 591   address base = binding()->section_start(CodeBuffer::SECT_INSTS);
 592   _owner = address_from_scaled_offset(unpack_1_int(), base);
 593 }
 594 
 595 void external_word_Relocation::pack_data_to(CodeSection* dest) {
 596   short* p = (short*) dest->locs_end();
 597 #ifndef _LP64
 598   p = pack_1_int_to(p, (int32_t) (intptr_t)_target);
 599 #else
 600   jlong t = (jlong) _target;
 601   int32_t lo = low(t);
 602   int32_t hi = high(t);
 603   p = pack_2_ints_to(p, lo, hi);
 604 #endif /* _LP64 */
 605   dest->set_locs_end((relocInfo*) p);
 606 }
 607 
 608 
 609 void external_word_Relocation::unpack_data() {
 610 #ifndef _LP64
 611   _target = (address) (intptr_t)unpack_1_int();
 612 #else
 613   int32_t lo, hi;
 614   unpack_2_ints(lo, hi);
 615   jlong t = jlong_from(hi, lo);;
 616   _target = (address) t;
 617 #endif /* _LP64 */
 618 }
 619 
 620 
 621 void internal_word_Relocation::pack_data_to(CodeSection* dest) {
 622   short* p = (short*) dest->locs_end();
 623   normalize_address(_target, dest, true);
 624 
 625   // Check whether my target address is valid within this section.
 626   // If not, strengthen the relocation type to point to another section.
 627   int sindex = _section;
 628   if (sindex == CodeBuffer::SECT_NONE && _target != NULL
 629       && (!dest->allocates(_target) || _target == dest->locs_point())) {
 630     sindex = dest->outer()->section_index_of(_target);
 631     guarantee(sindex != CodeBuffer::SECT_NONE, "must belong somewhere");
 632     relocInfo* base = dest->locs_end() - 1;
 633     assert(base->type() == this->type(), "sanity");
 634     // Change the written type, to be section_word_type instead.
 635     base->set_type(relocInfo::section_word_type);
 636   }
 637 
 638   // Note: An internal_word relocation cannot refer to its own instruction,
 639   // because we reserve "0" to mean that the pointer itself is embedded
 640   // in the code stream.  We use a section_word relocation for such cases.
 641 
 642   if (sindex == CodeBuffer::SECT_NONE) {
 643     assert(type() == relocInfo::internal_word_type, "must be base class");
 644     guarantee(_target == NULL || dest->allocates2(_target), "must be within the given code section");
 645     jint x0 = scaled_offset_null_special(_target, dest->locs_point());
 646     assert(!(x0 == 0 && _target != NULL), "correct encoding of null target");
 647     p = pack_1_int_to(p, x0);
 648   } else {
 649     assert(_target != NULL, "sanity");
 650     CodeSection* sect = dest->outer()->code_section(sindex);
 651     guarantee(sect->allocates2(_target), "must be in correct section");
 652     address base = sect->start();
 653     jint offset = scaled_offset(_target, base);
 654     assert((uint)sindex < (uint)CodeBuffer::SECT_LIMIT, "sanity");
 655     assert(CodeBuffer::SECT_LIMIT <= (1 << section_width), "section_width++");
 656     p = pack_1_int_to(p, (offset << section_width) | sindex);
 657   }
 658 
 659   dest->set_locs_end((relocInfo*) p);
 660 }
 661 
 662 
 663 void internal_word_Relocation::unpack_data() {
 664   jint x0 = unpack_1_int();
 665   _target = x0==0? NULL: address_from_scaled_offset(x0, addr());
 666   _section = CodeBuffer::SECT_NONE;
 667 }
 668 
 669 
 670 void section_word_Relocation::unpack_data() {
 671   jint    x      = unpack_1_int();
 672   jint    offset = (x >> section_width);
 673   int     sindex = (x & ((1<<section_width)-1));
 674   address base   = binding()->section_start(sindex);
 675 
 676   _section = sindex;
 677   _target  = address_from_scaled_offset(offset, base);
 678 }
 679 
 680 //// miscellaneous methods
 681 oop* oop_Relocation::oop_addr() {
 682   int n = _oop_index;
 683   if (n == 0) {
 684     // oop is stored in the code stream
 685     return (oop*) pd_address_in_code();
 686   } else {
 687     // oop is stored in table at nmethod::oops_begin
 688     return code()->oop_addr_at(n);
 689   }
 690 }
 691 
 692 
 693 oop oop_Relocation::oop_value() {
 694   oop v = *oop_addr();
 695   // clean inline caches store a special pseudo-null
 696   if (v == (oop)Universe::non_oop_word())  v = NULL;
 697   return v;
 698 }
 699 
 700 
 701 void oop_Relocation::fix_oop_relocation() {
 702   if (!oop_is_immediate()) {
 703     // get the oop from the pool, and re-insert it into the instruction:
 704     set_value(value());
 705   }
 706 }
 707 
 708 
 709 void oop_Relocation::verify_oop_relocation() {
 710   if (!oop_is_immediate()) {
 711     // get the oop from the pool, and re-insert it into the instruction:
 712     verify_value(value());
 713   }
 714 }
 715 
 716 // meta data versions
 717 Metadata** metadata_Relocation::metadata_addr() {
 718   int n = _metadata_index;
 719   if (n == 0) {
 720     // metadata is stored in the code stream
 721     return (Metadata**) pd_address_in_code();
 722     } else {
 723     // metadata is stored in table at nmethod::metadatas_begin
 724     return code()->metadata_addr_at(n);
 725     }
 726   }
 727 
 728 
 729 Metadata* metadata_Relocation::metadata_value() {
 730   Metadata* v = *metadata_addr();
 731   // clean inline caches store a special pseudo-null
 732   if (v == (Metadata*)Universe::non_oop_word())  v = NULL;
 733   return v;
 734   }
 735 
 736 
 737 void metadata_Relocation::fix_metadata_relocation() {
 738   if (!metadata_is_immediate()) {
 739     // get the metadata from the pool, and re-insert it into the instruction:
 740     pd_fix_value(value());
 741   }
 742 }
 743 
 744 
 745 void metadata_Relocation::verify_metadata_relocation() {
 746   if (!metadata_is_immediate()) {
 747     // get the metadata from the pool, and re-insert it into the instruction:
 748     verify_value(value());
 749   }
 750 }
 751 
 752 address virtual_call_Relocation::cached_value() {
 753   assert(_cached_value != NULL && _cached_value < addr(), "must precede ic_call");
 754   return _cached_value;
 755 }
 756 
 757 Method* virtual_call_Relocation::method_value() {
 758   CompiledMethod* cm = code();
 759   if (cm == NULL) return (Method*)NULL;
 760   Metadata* m = cm->metadata_at(_method_index);
 761   assert(m != NULL || _method_index == 0, "should be non-null for non-zero index");
 762   assert(m == NULL || m->is_method(), "not a method");
 763   return (Method*)m;
 764 }
 765 
 766 void virtual_call_Relocation::clear_inline_cache() {
 767   // No stubs for ICs
 768   // Clean IC
 769   ResourceMark rm;
 770   CompiledIC* icache = CompiledIC_at(this);
 771   icache->set_to_clean();
 772 }
 773 
 774 
 775 void opt_virtual_call_Relocation::pack_data_to(CodeSection* dest) {
 776   short* p = (short*) dest->locs_end();
 777   p = pack_1_int_to(p, _method_index);
 778   dest->set_locs_end((relocInfo*) p);
 779 }
 780 
 781 void opt_virtual_call_Relocation::unpack_data() {
 782   _method_index = unpack_1_int();
 783 }
 784 
 785 Method* opt_virtual_call_Relocation::method_value() {
 786   CompiledMethod* cm = code();
 787   if (cm == NULL) return (Method*)NULL;
 788   Metadata* m = cm->metadata_at(_method_index);
 789   assert(m != NULL || _method_index == 0, "should be non-null for non-zero index");
 790   assert(m == NULL || m->is_method(), "not a method");
 791   return (Method*)m;
 792 }
 793 
 794 void opt_virtual_call_Relocation::clear_inline_cache() {
 795   // No stubs for ICs
 796   // Clean IC
 797   ResourceMark rm;
 798   CompiledIC* icache = CompiledIC_at(this);
 799   icache->set_to_clean();
 800 }
 801 
 802 
 803 address opt_virtual_call_Relocation::static_stub(bool is_aot) {
 804   // search for the static stub who points back to this static call
 805   address static_call_addr = addr();
 806   RelocIterator iter(code());
 807   while (iter.next()) {
 808     if (iter.type() == relocInfo::static_stub_type) {
 809       static_stub_Relocation* stub_reloc = iter.static_stub_reloc();
 810       if (stub_reloc->static_call() == static_call_addr && stub_reloc->is_aot() == is_aot) {
 811         return iter.addr();
 812       }
 813     }
 814   }
 815   return NULL;
 816 }
 817 
 818 Method* static_call_Relocation::method_value() {
 819   CompiledMethod* cm = code();
 820   if (cm == NULL) return (Method*)NULL;
 821   Metadata* m = cm->metadata_at(_method_index);
 822   assert(m != NULL || _method_index == 0, "should be non-null for non-zero index");
 823   assert(m == NULL || m->is_method(), "not a method");
 824   return (Method*)m;
 825 }
 826 
 827 void static_call_Relocation::pack_data_to(CodeSection* dest) {
 828   short* p = (short*) dest->locs_end();
 829   p = pack_1_int_to(p, _method_index);
 830   dest->set_locs_end((relocInfo*) p);
 831 }
 832 
 833 void static_call_Relocation::unpack_data() {
 834   _method_index = unpack_1_int();
 835 }
 836 
 837 void static_call_Relocation::clear_inline_cache() {
 838   // Safe call site info
 839   CompiledStaticCall* handler = this->code()->compiledStaticCall_at(this);
 840   handler->set_to_clean();
 841 }
 842 
 843 
 844 address static_call_Relocation::static_stub(bool is_aot) {
 845   // search for the static stub who points back to this static call
 846   address static_call_addr = addr();
 847   RelocIterator iter(code());
 848   while (iter.next()) {
 849     if (iter.type() == relocInfo::static_stub_type) {
 850       static_stub_Relocation* stub_reloc = iter.static_stub_reloc();
 851       if (stub_reloc->static_call() == static_call_addr && stub_reloc->is_aot() == is_aot) {
 852         return iter.addr();
 853       }
 854     }
 855   }
 856   return NULL;
 857 }
 858 
 859 // Finds the trampoline address for a call. If no trampoline stub is
 860 // found NULL is returned which can be handled by the caller.
 861 address trampoline_stub_Relocation::get_trampoline_for(address call, nmethod* code) {
 862   // There are no relocations available when the code gets relocated
 863   // because of CodeBuffer expansion.
 864   if (code->relocation_size() == 0)
 865     return NULL;
 866 
 867   RelocIterator iter(code, call);
 868   while (iter.next()) {
 869     if (iter.type() == relocInfo::trampoline_stub_type) {
 870       if (iter.trampoline_stub_reloc()->owner() == call) {
 871         return iter.addr();
 872       }
 873     }
 874   }
 875 
 876   return NULL;
 877 }
 878 
 879 void static_stub_Relocation::clear_inline_cache() {
 880   // Call stub is only used when calling the interpreted code.
 881   // It does not really need to be cleared, except that we want to clean out the methodoop.
 882   CompiledDirectStaticCall::set_stub_to_clean(this);
 883 }
 884 
 885 
 886 void external_word_Relocation::fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) {
 887   address target = _target;
 888   if (target == NULL) {
 889     // An absolute embedded reference to an external location,
 890     // which means there is nothing to fix here.
 891     return;
 892   }
 893   // Probably this reference is absolute, not relative, so the
 894   // following is probably a no-op.
 895   assert(src->section_index_of(target) == CodeBuffer::SECT_NONE, "sanity");
 896   set_value(target);
 897 }
 898 
 899 
 900 address external_word_Relocation::target() {
 901   address target = _target;
 902   if (target == NULL) {
 903     target = pd_get_address_from_code();
 904   }
 905   return target;
 906 }
 907 
 908 
 909 void internal_word_Relocation::fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) {
 910   address target = _target;
 911   if (target == NULL) {
 912     target = new_addr_for(this->target(), src, dest);
 913   }
 914   set_value(target);
 915 }
 916 
 917 
 918 address internal_word_Relocation::target() {
 919   address target = _target;
 920   if (target == NULL) {
 921     if (addr_in_const()) {
 922       target = *(address*)addr();
 923     } else {
 924       target = pd_get_address_from_code();
 925     }
 926   }
 927   return target;
 928 }
 929 
 930 //---------------------------------------------------------------------------------
 931 // Non-product code
 932 
 933 #ifndef PRODUCT
 934 
 935 static const char* reloc_type_string(relocInfo::relocType t) {
 936   switch (t) {
 937   #define EACH_CASE(name) \
 938   case relocInfo::name##_type: \
 939     return #name;
 940 
 941   APPLY_TO_RELOCATIONS(EACH_CASE);
 942   #undef EACH_CASE
 943 
 944   case relocInfo::none:
 945     return "none";
 946   case relocInfo::data_prefix_tag:
 947     return "prefix";
 948   default:
 949     return "UNKNOWN RELOC TYPE";
 950   }
 951 }
 952 
 953 
 954 void RelocIterator::print_current() {
 955   if (!has_current()) {
 956     tty->print_cr("(no relocs)");
 957     return;
 958   }
 959   tty->print("relocInfo@" INTPTR_FORMAT " [type=%d(%s) addr=" INTPTR_FORMAT " offset=%d",
 960              p2i(_current), type(), reloc_type_string((relocInfo::relocType) type()), p2i(_addr), _current->addr_offset());
 961   if (current()->format() != 0)
 962     tty->print(" format=%d", current()->format());
 963   if (datalen() == 1) {
 964     tty->print(" data=%d", data()[0]);
 965   } else if (datalen() > 0) {
 966     tty->print(" data={");
 967     for (int i = 0; i < datalen(); i++) {
 968       tty->print("%04x", data()[i] & 0xFFFF);
 969     }
 970     tty->print("}");
 971   }
 972   tty->print("]");
 973   switch (type()) {
 974   case relocInfo::oop_type:
 975     {
 976       oop_Relocation* r = oop_reloc();
 977       oop* oop_addr  = NULL;
 978       oop  raw_oop   = NULL;
 979       oop  oop_value = NULL;
 980       if (code() != NULL || r->oop_is_immediate()) {
 981         oop_addr  = r->oop_addr();
 982         raw_oop   = *oop_addr;
 983         oop_value = r->oop_value();
 984       }
 985       tty->print(" | [oop_addr=" INTPTR_FORMAT " *=" INTPTR_FORMAT " offset=%d]",
 986                  p2i(oop_addr), p2i(raw_oop), r->offset());
 987       // Do not print the oop by default--we want this routine to
 988       // work even during GC or other inconvenient times.
 989       if (WizardMode && oop_value != NULL) {
 990         tty->print("oop_value=" INTPTR_FORMAT ": ", p2i(oop_value));
 991         if (oop_value->is_oop()) {
 992           oop_value->print_value_on(tty);
 993         }
 994       }
 995       break;
 996     }
 997   case relocInfo::metadata_type:
 998     {
 999       metadata_Relocation* r = metadata_reloc();
1000       Metadata** metadata_addr  = NULL;
1001       Metadata*    raw_metadata   = NULL;
1002       Metadata*    metadata_value = NULL;
1003       if (code() != NULL || r->metadata_is_immediate()) {
1004         metadata_addr  = r->metadata_addr();
1005         raw_metadata   = *metadata_addr;
1006         metadata_value = r->metadata_value();
1007       }
1008       tty->print(" | [metadata_addr=" INTPTR_FORMAT " *=" INTPTR_FORMAT " offset=%d]",
1009                  p2i(metadata_addr), p2i(raw_metadata), r->offset());
1010       if (metadata_value != NULL) {
1011         tty->print("metadata_value=" INTPTR_FORMAT ": ", p2i(metadata_value));
1012         metadata_value->print_value_on(tty);
1013       }
1014       break;
1015     }
1016   case relocInfo::external_word_type:
1017   case relocInfo::internal_word_type:
1018   case relocInfo::section_word_type:
1019     {
1020       DataRelocation* r = (DataRelocation*) reloc();
1021       tty->print(" | [target=" INTPTR_FORMAT "]", p2i(r->value())); //value==target
1022       break;
1023     }
1024   case relocInfo::static_call_type:
1025     {
1026       static_call_Relocation* r = (static_call_Relocation*) reloc();
1027       tty->print(" | [destination=" INTPTR_FORMAT " metadata=" INTPTR_FORMAT "]",
1028                  p2i(r->destination()), p2i(r->method_value()));
1029       break;
1030     }
1031   case relocInfo::runtime_call_type:
1032   case relocInfo::runtime_call_w_cp_type:
1033     {
1034       CallRelocation* r = (CallRelocation*) reloc();
1035       tty->print(" | [destination=" INTPTR_FORMAT "]", p2i(r->destination()));
1036       break;
1037     }
1038   case relocInfo::virtual_call_type:
1039     {
1040       virtual_call_Relocation* r = (virtual_call_Relocation*) reloc();
1041       tty->print(" | [destination=" INTPTR_FORMAT " cached_value=" INTPTR_FORMAT " metadata=" INTPTR_FORMAT "]",
1042                  p2i(r->destination()), p2i(r->cached_value()), p2i(r->method_value()));
1043       break;
1044     }
1045   case relocInfo::static_stub_type:
1046     {
1047       static_stub_Relocation* r = (static_stub_Relocation*) reloc();
1048       tty->print(" | [static_call=" INTPTR_FORMAT "]", p2i(r->static_call()));
1049       break;
1050     }
1051   case relocInfo::trampoline_stub_type:
1052     {
1053       trampoline_stub_Relocation* r = (trampoline_stub_Relocation*) reloc();
1054       tty->print(" | [trampoline owner=" INTPTR_FORMAT "]", p2i(r->owner()));
1055       break;
1056     }
1057   case relocInfo::opt_virtual_call_type:
1058     {
1059       opt_virtual_call_Relocation* r = (opt_virtual_call_Relocation*) reloc();
1060       tty->print(" | [destination=" INTPTR_FORMAT " metadata=" INTPTR_FORMAT "]",
1061                  p2i(r->destination()), p2i(r->method_value()));
1062       break;
1063     }
1064   }
1065   tty->cr();
1066 }
1067 
1068 
1069 void RelocIterator::print() {
1070   RelocIterator save_this = (*this);
1071   relocInfo* scan = _current;
1072   if (!has_current())  scan += 1;  // nothing to scan here!
1073 
1074   bool skip_next = has_current();
1075   bool got_next;
1076   while (true) {
1077     got_next = (skip_next || next());
1078     skip_next = false;
1079 
1080     tty->print("         @" INTPTR_FORMAT ": ", p2i(scan));
1081     relocInfo* newscan = _current+1;
1082     if (!has_current())  newscan -= 1;  // nothing to scan here!
1083     while (scan < newscan) {
1084       tty->print("%04x", *(short*)scan & 0xFFFF);
1085       scan++;
1086     }
1087     tty->cr();
1088 
1089     if (!got_next)  break;
1090     print_current();
1091   }
1092 
1093   (*this) = save_this;
1094 }
1095 
1096 // For the debugger:
1097 extern "C"
1098 void print_blob_locs(nmethod* nm) {
1099   nm->print();
1100   RelocIterator iter(nm);
1101   iter.print();
1102 }
1103 extern "C"
1104 void print_buf_locs(CodeBuffer* cb) {
1105   FlagSetting fs(PrintRelocations, true);
1106   cb->print();
1107 }
1108 #endif // !PRODUCT