src/ld/passes/order.cpp

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  24
  25
  26 #include <stdint.h>
  27 #include <math.h>
  28 #include <unistd.h>
  29 #include <dlfcn.h>
  30 #include <mach/machine.h>
  31
  32 #include <vector>
  33 #include <map>
  34 #include <set>
  35 #include <unordered_map>
  36
  37 #include "ld.hpp"
  38 #include "order.h"
  39
  40 namespace ld {
  41 namespace passes {
  42 namespace order {
  43
  44 //
  45 // The purpose of this pass is to take the graph of all Atoms and produce an ordered
  46 // sequence of atoms.  The constraints are that: 1) all Atoms of the same Segment must
  47 // be contiguous, 2)  all Atoms of the same Section must be contigous, 3) Atoms specified
  48 // in an order are sequenced as in the order file and before Atoms not specified,
  49 // 4) Atoms in the same section from the same .o file should be contiguous and sequenced
  50 // in the same order they were in the .o file, 5) Atoms in the same Section but which came
  51 // from different .o files should be sequenced in the same order that the .o files
  52 // were passed to the linker (i.e. command line order).
  53 //
  54 // The way this is implemented is that the linker passes a "base ordinal" to each File
  55 // as it is constructed. Add each atom has an objectAddress() method. Then
  56 // sorting is just sorting by section, then by file ordinal, then by object address.
  57 //
  58 // If an -order_file is specified, it gets more complicated.  First, an override-ordinal map
  59 // is created.  It causes the sort routine to ignore the value returned by ordinal() and objectAddress()
  60 // and use the override value instead.  Next some Atoms must be laid out consecutively
  61 // (e.g. hand written assembly that does not end with return, but rather falls into
  62 // the next label).  This is modeled in via a kindNoneFollowOn fixup.  The use of
  63 // kindNoneFollowOn fixups produces "clusters" of atoms that must stay together.
  64 // If an order_file tries to move one atom, it may need to move a whole cluster.  The
  65 // algorithm to do this models clusters using two maps.  The "starts" maps maps any
  66 // atom in a cluster to the first Atom in the cluster.  The "nexts" maps an Atom in a
  67 // cluster to the next Atom in the cluster.  With this in place, while processing an
  68 // order_file, if any entry is in a cluster (in "starts" map), then the entire cluster is
  69 // given ordinal overrides.
  70 //
  71
  72 class Layout
  73 {
  74 public:
  75                                 Layout(const Options& opts, ld::Internal& state);
  76         void            doPass();
  77 private:
  78
  79         class Comparer {
  80         public:
  81                                         Comparer(const Layout& l) : _layout(l) {}
  82                 bool            operator()(const ld::Atom* left, const ld::Atom* right);
  83         private:
  84                 const Layout&   _layout;
  85         };
  86
  87         typedef std::unordered_map<const char*, const ld::Atom*, CStringHash, CStringEquals> NameToAtom;
  88
  89         typedef std::map<const ld::Atom*, const ld::Atom*> AtomToAtom;
  90
  91         typedef std::map<const ld::Atom*, uint32_t> AtomToOrdinal;
  92
  93         const ld::Atom*         findAtom(const Options::OrderedSymbol& orderedSymbol);
  94         void                            buildNameTable();
  95         void                            buildFollowOnTables();
  96         void                            buildOrdinalOverrideMap();
  97         const ld::Atom*         follower(const ld::Atom* atom);
  98         static bool                     matchesObjectFile(const ld::Atom* atom, const char* objectFileLeafName);
  99                         bool            possibleToOrder(const ld::Internal::FinalSection*);
 100
 101         const Options&                                          _options;
 102         ld::Internal&                                           _state;
 103         AtomToAtom                                                      _followOnStarts;
 104         AtomToAtom                                                      _followOnNexts;
 105         NameToAtom                                                      _nameTable;
 106         std::vector<const ld::Atom*>            _nameCollisionAtoms;
 107         AtomToOrdinal                                           _ordinalOverrideMap;
 108         Comparer                                                        _comparer;
 109         bool                                                            _haveOrderFile;
 110
 111         static bool                                                     _s_log;
 112 };
 113
 114 bool Layout::_s_log = false;
 115
 116 Layout::Layout(const Options& opts, ld::Internal& state)
 117         : _options(opts), _state(state), _comparer(*this), _haveOrderFile(opts.orderedSymbolsCount() != 0)
 118 {
 119 }
 120
 121
 122 bool Layout::Comparer::operator()(const ld::Atom* left, const ld::Atom* right)
 123 {
 124         if ( left == right )
 125                 return false;
 126
 127         // magic section$start symbol always sorts to the start of its section
 128         if ( left->contentType() == ld::Atom::typeSectionStart )
 129                 return true;
 130         if ( right->contentType() == ld::Atom::typeSectionStart )
 131                 return false;
 132
 133         // if an -order_file is specified, then sorting is altered to sort those symbols first
 134         if ( _layout._haveOrderFile ) {
 135                 AtomToOrdinal::const_iterator leftPos  = _layout._ordinalOverrideMap.find(left);
 136                 AtomToOrdinal::const_iterator rightPos = _layout._ordinalOverrideMap.find(right);
 137                 AtomToOrdinal::const_iterator end = _layout._ordinalOverrideMap.end();
 138                 if ( leftPos != end ) {
 139                         if ( rightPos != end ) {
 140                                 // both left and right are overridden, so compare overridden ordinals
 141                                 return leftPos->second < rightPos->second;
 142                         }
 143                         else {
 144                                 // left is overridden and right is not, so left < right
 145                                 return true;
 146                         }
 147                 }
 148                 else {
 149                         if ( rightPos != end ) {
 150                                 // right is overridden and left is not, so right < left
 151                                 return false;
 152                         }
 153                         else {
 154                                 // neither are overridden,
 155                                 // fall into default sorting below
 156                         }
 157                 }
 158         }
 159
 160         // magic section$end symbol always sorts to the end of its section
 161         if ( left->contentType() == ld::Atom::typeSectionEnd )
 162                 return false;
 163         if ( right->contentType() == ld::Atom::typeSectionEnd )
 164                 return true;
 165
 166         // aliases sort before their target
 167         bool leftIsAlias = left->isAlias();
 168         if ( leftIsAlias ) {
 169                 for (ld::Fixup::iterator fit=left->fixupsBegin(); fit != left->fixupsEnd(); ++fit) {
 170                         if ( fit->kind == ld::Fixup::kindNoneFollowOn ) {
 171                                 assert(fit->binding == ld::Fixup::bindingDirectlyBound);
 172                             if ( fit->u.target == right )
 173                                         return true; // left already before right
 174                                 left = fit->u.target; // sort as if alias was its target
 175                                 break;
 176                     }
 177                 }
 178         }
 179         bool rightIsAlias = right->isAlias();
 180     if ( rightIsAlias ) {
 181         for (ld::Fixup::iterator fit=right->fixupsBegin(); fit != right->fixupsEnd(); ++fit) {
 182                         if ( fit->kind == ld::Fixup::kindNoneFollowOn ) {
 183                                 assert(fit->binding == ld::Fixup::bindingDirectlyBound);
 184                 if ( fit->u.target == left )
 185                     return false; // need to swap, alias is after target
 186                                 right = fit->u.target; // continue with sort as if right was target
 187                 break;
 188                         }
 189                 }
 190     }
 191
 192         // the __common section can have real or tentative definitions
 193         // we want the real ones to sort before tentative ones
 194         bool leftIsTent  =  (left->definition() == ld::Atom::definitionTentative);
 195         bool rightIsTent =  (right->definition() == ld::Atom::definitionTentative);
 196         if ( leftIsTent != rightIsTent )
 197                 return rightIsTent;
 198
 199 #if 0
 200         // initializers are auto sorted to start of section
 201         if ( !fInitializerSet.empty() ) {
 202                 bool leftFirst  = (fInitializerSet.count(left) != 0);
 203                 bool rightFirst = (fInitializerSet.count(right) != 0);
 204                 if ( leftFirst != rightFirst )
 205                         return leftFirst;
 206         }
 207
 208         // terminators are auto sorted to end of section
 209         if ( !fTerminatorSet.empty() ) {
 210                 bool leftLast  = (fTerminatorSet.count(left) != 0);
 211                 bool rightLast = (fTerminatorSet.count(right) != 0);
 212                 if ( leftLast != rightLast )
 213                         return rightLast;
 214         }
 215 #endif
 216
 217         // sort by .o order
 218         const ld::File* leftFile = left->file();
 219         const ld::File* rightFile = right->file();
 220         // <rdar://problem/10830126> properly sort if on file is NULL and the other is not
 221         ld::File::Ordinal leftFileOrdinal = (leftFile != NULL) ? leftFile->ordinal() : ld::File::Ordinal::NullOrdinal();
 222         ld::File::Ordinal rightFileOrdinal = (rightFile != NULL) ? rightFile->ordinal() : ld::File::Ordinal::NullOrdinal();
 223         if ( leftFileOrdinal != rightFileOrdinal )
 224                 return leftFileOrdinal< rightFileOrdinal;
 225
 226         // tentative defintions have no address in .o file, they are traditionally laid out by name
 227         if ( leftIsTent && rightIsTent )
 228                 return (strcmp(left->name(), right->name()) < 0);
 229
 230         // lastly sort by atom address
 231         int64_t addrDiff = left->objectAddress() - right->objectAddress();
 232         if ( addrDiff == 0 ) {
 233                 // have same address so one might be an alias, and aliases need to sort before target
 234                 if ( leftIsAlias != rightIsAlias )
 235                         return leftIsAlias;
 236
 237                 // both at same address, sort by name
 238                 return (strcmp(left->name(), right->name()) < 0);
 239         }
 240         return (addrDiff < 0);
 241 }
 242
 243 bool Layout::matchesObjectFile(const ld::Atom* atom, const char* objectFileLeafName)
 244 {
 245         if ( objectFileLeafName == NULL )
 246                 return true;
 247         const char* atomFullPath = atom->file()->path();
 248         const char* lastSlash = strrchr(atomFullPath, '/');
 249         if ( lastSlash != NULL ) {
 250                 if ( strcmp(&lastSlash[1], objectFileLeafName) == 0 )
 251                         return true;
 252         }
 253         else {
 254                 if ( strcmp(atomFullPath, objectFileLeafName) == 0 )
 255                         return true;
 256         }
 257         return false;
 258 }
 259
 260
 261 bool Layout::possibleToOrder(const ld::Internal::FinalSection* sect)
 262 {
 263         // atoms in only some sections can have order_file applied
 264         switch ( sect->type() ) {
 265                 case ld::Section::typeUnclassified:
 266                 case ld::Section::typeCode:
 267                 case ld::Section::typeZeroFill:
 268                         return true;
 269                 case ld::Section::typeImportProxies:
 270                         return false;
 271                 default:
 272                         // if section has command line aliases, then we must apply ordering so aliases layout before targets
 273                         if ( _options.haveCmdLineAliases() ) {
 274                                 for (std::vector<const ld::Atom*>::const_iterator ait=sect->atoms.begin(); ait != sect->atoms.end(); ++ait) {
 275                                         const ld::Atom* atom = *ait;
 276                                         if ( atom->isAlias() )
 277                                                 return true;
 278                                 }
 279                         }
 280                         break;
 281         }
 282         return false;
 283 }
 284
 285 void Layout::buildNameTable()
 286 {
 287         for (std::vector<ld::Internal::FinalSection*>::iterator sit=_state.sections.begin(); sit != _state.sections.end(); ++sit) {
 288                 ld::Internal::FinalSection* sect = *sit;
 289                 // some sections are not worth scanning for names
 290                 if ( ! possibleToOrder(sect) )
 291                         continue;
 292                 for (std::vector<const ld::Atom*>::iterator ait=sect->atoms.begin(); ait != sect->atoms.end(); ++ait) {
 293                         const ld::Atom* atom = *ait;
 294                         if ( atom->symbolTableInclusion() == ld::Atom::symbolTableIn ) {
 295                                 const char* name = atom->name();
 296                                 if ( name != NULL) {
 297                                         // static function or data
 298                                         NameToAtom::iterator pos = _nameTable.find(name);
 299                                         if ( pos == _nameTable.end() )
 300                                                 _nameTable[name] = atom;
 301                                         else {
 302                                                 const ld::Atom* existing = _nameTable[name];
 303                                                 if ( existing != NULL ) {
 304                                                         _nameCollisionAtoms.push_back(existing);
 305                                                         _nameTable[name] = NULL;        // collision, denote with NULL
 306                                                 }
 307                                                 _nameCollisionAtoms.push_back(atom);
 308                                         }
 309                                 }
 310                         }
 311                 }
 312         }
 313         if ( _s_log ) {
 314                 fprintf(stderr, "buildNameTable() _nameTable:\n");
 315                 for(NameToAtom::iterator it=_nameTable.begin(); it != _nameTable.end(); ++it)
 316                         fprintf(stderr, "  %p <- %s\n", it->second, it->first);
 317                 fprintf(stderr, "buildNameTable() _nameCollisionAtoms:\n");
 318                 for(std::vector<const ld::Atom*>::iterator it=_nameCollisionAtoms.begin(); it != _nameCollisionAtoms.end(); ++it)
 319                         fprintf(stderr, "  %p, %s\n", *it, (*it)->name());
 320         }
 321 }
 322
 323
 324 const ld::Atom* Layout::findAtom(const Options::OrderedSymbol& orderedSymbol)
 325 {
 326         // look for name in _nameTable
 327         NameToAtom::iterator pos = _nameTable.find(orderedSymbol.symbolName);
 328         if ( pos != _nameTable.end() ) {
 329                 if ( (pos->second != NULL) && matchesObjectFile(pos->second, orderedSymbol.objectFileName) ) {
 330                         //fprintf(stderr, "found %s in hash table\n", orderedSymbol.symbolName);
 331                         return pos->second;
 332                 }
 333                 if ( pos->second == NULL ) {
 334                         // name is in hash table, but atom is NULL, so that means there are duplicates, so we use super slow way
 335                         if ( ( orderedSymbol.objectFileName == NULL) && _options.printOrderFileStatistics() ) {
 336                                 warning("%s specified in order_file but it exists in multiple .o files. "
 337                                                 "Prefix symbol with .o filename in order_file to disambiguate", orderedSymbol.symbolName);
 338                         }
 339                         for (std::vector<const ld::Atom*>::iterator it=_nameCollisionAtoms.begin(); it != _nameCollisionAtoms.end(); it++) {
 340                                 const ld::Atom* atom = *it;
 341                                 if ( strcmp(atom->name(), orderedSymbol.symbolName) == 0 ) {
 342                                         if ( matchesObjectFile(atom, orderedSymbol.objectFileName) ) {
 343                                                 return atom;
 344                                         }
 345                                 }
 346                         }
 347                 }
 348         }
 349
 350         return NULL;
 351 }
 352
 353 const ld::Atom* Layout::follower(const ld::Atom* atom)
 354 {
 355         for (const ld::Atom* a = _followOnStarts[atom]; a != NULL; a = _followOnNexts[a]) {
 356                 assert(a != NULL);
 357                 if ( _followOnNexts[a] == atom ) {
 358                         return a;
 359                 }
 360         }
 361         // no follower, first in chain
 362         return NULL;
 363 }
 364
 365 void Layout::buildFollowOnTables()
 366 {
 367         // if no -order_file, then skip building follow on table
 368         if ( ! _haveOrderFile )
 369                 return;
 370
 371         // first make a pass to find all follow-on references and build start/next maps
 372         // which are a way to represent clusters of atoms that must layout together
 373         for (std::vector<ld::Internal::FinalSection*>::iterator sit=_state.sections.begin(); sit != _state.sections.end(); ++sit) {
 374                 ld::Internal::FinalSection* sect = *sit;
 375                 if ( !possibleToOrder(sect) )
 376                         continue;
 377                 for (std::vector<const ld::Atom*>::iterator ait=sect->atoms.begin(); ait != sect->atoms.end(); ++ait) {
 378                         const ld::Atom* atom = *ait;
 379                         for (ld::Fixup::iterator fit = atom->fixupsBegin(), end=atom->fixupsEnd(); fit != end; ++fit) {
 380                                 if ( fit->kind == ld::Fixup::kindNoneFollowOn ) {
 381                                         assert(fit->binding == ld::Fixup::bindingDirectlyBound);
 382                                         const ld::Atom* followOnAtom = fit->u.target;
 383                                         if ( _s_log ) fprintf(stderr, "ref %p %s -> %p %s\n", atom, atom->name(), followOnAtom, followOnAtom->name());
 384                                         assert(_followOnNexts.count(atom) == 0);
 385                                         _followOnNexts[atom] = followOnAtom;
 386                                         if ( _followOnStarts.count(atom) == 0 ) {
 387                                                 // first time atom has been seen, make it start of chain
 388                                                 _followOnStarts[atom] = atom;
 389                                                 if ( _s_log ) fprintf(stderr, "  start %s -> %s\n", atom->name(), atom->name());
 390                                         }
 391                                         if ( _followOnStarts.count(followOnAtom) == 0 ) {
 392                                                 // first time followOnAtom has been seen, make atom start of chain
 393                                                 _followOnStarts[followOnAtom] = _followOnStarts[atom];
 394                                                 if ( _s_log ) fprintf(stderr, "  start %s -> %s\n", followOnAtom->name(), _followOnStarts[atom]->name());
 395                                         }
 396                                         else {
 397                                                 if ( _followOnStarts[followOnAtom] == followOnAtom ) {
 398                                                         // followOnAtom atom already start of another chain, hook together
 399                                                         // and change all to use atom as start
 400                                                         const ld::Atom* a = followOnAtom;
 401                                                         while ( true ) {
 402                                                                 assert(_followOnStarts[a] == followOnAtom);
 403                                                                 _followOnStarts[a] = _followOnStarts[atom];
 404                                                                 if ( _s_log ) fprintf(stderr, "  adjust start for %s -> %s\n", a->name(), _followOnStarts[atom]->name());
 405                                                                 AtomToAtom::iterator pos = _followOnNexts.find(a);
 406                                                                 if ( pos != _followOnNexts.end() )
 407                                                                         a = pos->second;
 408                                                                 else
 409                                                                         break;
 410                                                         }
 411                                                 }
 412                                                 else {
 413                                                         // attempt to insert atom into existing followOn chain
 414                                                         const ld::Atom* curPrevToFollowOnAtom = this->follower(followOnAtom);
 415                                                         assert(curPrevToFollowOnAtom != NULL);
 416                                                         assert((atom->size() == 0) || (curPrevToFollowOnAtom->size() == 0));
 417                                                         if ( atom->size() == 0 ) {
 418                                                                 // insert alias into existing chain right before followOnAtom
 419                                                                 _followOnNexts[curPrevToFollowOnAtom] = atom;
 420                                                                 _followOnNexts[atom] = followOnAtom;
 421                                                                 _followOnStarts[atom] = _followOnStarts[followOnAtom];
 422                                                         }
 423                                                         else {
 424                                                                 // insert real atom into existing chain right before alias of followOnAtom
 425                                                                 const ld::Atom* curPrevPrevToFollowOn = this->follower(curPrevToFollowOnAtom);
 426                                                                 if ( curPrevPrevToFollowOn == NULL ) {
 427                                                                         // nothing previous, so make this a start of a new chain
 428                                                                         _followOnNexts[atom] = curPrevToFollowOnAtom;
 429                                                                         for (const ld::Atom* a = atom; a != NULL; a = _followOnNexts[a]) {
 430                                                                                 if ( _s_log ) fprintf(stderr, "  adjust start for %s -> %s\n", a->name(), atom->name());
 431                                                                                 _followOnStarts[a] = atom;
 432                                                                         }
 433                                                                 }
 434                                                                 else {
 435                                                                         // is previous, insert into existing chain before previous
 436                                                                         _followOnNexts[curPrevPrevToFollowOn] = atom;
 437                                                                         _followOnNexts[atom] = curPrevToFollowOnAtom;
 438                                                                         _followOnStarts[atom] = _followOnStarts[curPrevToFollowOnAtom];
 439                                                                 }
 440                                                         }
 441                                                 }
 442                                         }
 443                                 }
 444                         }
 445                 }
 446         }
 447
 448         if ( _s_log ) {
 449                 for(AtomToAtom::iterator it = _followOnStarts.begin(); it != _followOnStarts.end(); ++it)
 450                         fprintf(stderr, "start %s -> %s\n", it->first->name(), it->second->name());
 451
 452                 for(AtomToAtom::iterator it = _followOnNexts.begin(); it != _followOnNexts.end(); ++it)
 453                         fprintf(stderr, "next %s -> %s\n", it->first->name(), (it->second != NULL) ? it->second->name() : "null");
 454         }
 455 }
 456
 457
 458 class InSet
 459 {
 460 public:
 461         InSet(const std::set<const ld::Atom*>& theSet) : _set(theSet)  {}
 462
 463         bool operator()(const ld::Atom* atom) const {
 464                 return ( _set.count(atom) != 0 );
 465         }
 466 private:
 467         const std::set<const ld::Atom*>&  _set;
 468 };
 469
 470
 471 void Layout::buildOrdinalOverrideMap()
 472 {
 473         // if no -order_file, then skip building override map
 474         if ( ! _haveOrderFile )
 475                 return;
 476
 477         // build fast name->atom table
 478         this->buildNameTable();
 479
 480         // handle .o files that cannot have their atoms rearranged
 481         // with the start/next maps of follow-on atoms we can process the order file and produce override ordinals
 482         uint32_t index = 0;
 483         uint32_t matchCount = 0;
 484         std::set<const ld::Atom*> moveToData;
 485         for(Options::OrderedSymbolsIterator it = _options.orderedSymbolsBegin(); it != _options.orderedSymbolsEnd(); ++it) {
 486                 const ld::Atom* atom = this->findAtom(*it);
 487                 if ( atom != NULL ) {
 488                         // <rdar://problem/8612550> When order file used on data, turn ordered zero fill symbols into zero data
 489                         switch ( atom->section().type() ) {
 490                                 case ld::Section::typeZeroFill:
 491                                 case ld::Section::typeTentativeDefs:
 492                                         if ( atom->size() <= 512 )
 493                                                 moveToData.insert(atom);
 494                                         break;
 495                                 default:
 496                                         break;
 497                         }
 498
 499                         AtomToAtom::iterator start = _followOnStarts.find(atom);
 500                         if ( start != _followOnStarts.end() ) {
 501                                 // this symbol for the order file corresponds to an atom that is in a cluster that must lay out together
 502                                 for(const ld::Atom* nextAtom = start->second; nextAtom != NULL; nextAtom = _followOnNexts[nextAtom]) {
 503                                         AtomToOrdinal::iterator pos = _ordinalOverrideMap.find(nextAtom);
 504                                         if ( pos == _ordinalOverrideMap.end() ) {
 505                                                 _ordinalOverrideMap[nextAtom] = index++;
 506                                                 if (_s_log ) fprintf(stderr, "override ordinal %u assigned to %s in cluster from %s\n", index, nextAtom->name(), nextAtom->file()->path());
 507                                         }
 508                                         else {
 509                                                 if (_s_log ) fprintf(stderr, "could not order %s as %u because it was already laid out earlier by %s as %u\n",
 510                                                                                 atom->name(), index, _followOnStarts[atom]->name(), _ordinalOverrideMap[atom] );
 511                                         }
 512                                 }
 513                         }
 514                         else {
 515                                 _ordinalOverrideMap[atom] = index;
 516                                 if (_s_log ) fprintf(stderr, "override ordinal %u assigned to %s from %s\n", index, atom->name(), atom->file()->path());
 517                         }
 518                         ++matchCount;
 519                 }
 520                 else {
 521                         if ( _options.printOrderFileStatistics() ) {
 522                                 if ( it->objectFileName == NULL )
 523                                         warning("can't find match for order_file entry: %s", it->symbolName);
 524                                 else
 525                                         warning("can't find match for order_file entry: %s/%s", it->objectFileName, it->symbolName);
 526                         }
 527                 }
 528                  ++index;
 529         }
 530         if ( _options.printOrderFileStatistics() && (_options.orderedSymbolsCount() != matchCount) ) {
 531                 warning("only %u out of %lu order_file symbols were applicable", matchCount, _options.orderedSymbolsCount() );
 532         }
 533
 534         // <rdar://problem/8612550> When order file used on data, turn ordered zero fill symbols into zeroed data
 535         if ( ! moveToData.empty() ) {
 536                 // <rdar://problem/14919139> only move zero fill symbols to __data if there is a __data section
 537                 ld::Internal::FinalSection* dataSect = NULL;
 538                 for (std::vector<ld::Internal::FinalSection*>::iterator sit=_state.sections.begin(); sit != _state.sections.end(); ++sit) {
 539                         ld::Internal::FinalSection* sect = *sit;
 540                         if ( sect->type() == ld::Section::typeUnclassified ) {
 541                                 if ( (strcmp(sect->sectionName(), "__data") == 0) && (strcmp(sect->segmentName(), "__DATA") == 0) )
 542                                         dataSect = sect;
 543                         }
 544                 }
 545
 546                 if ( dataSect != NULL ) {
 547                         // add atoms to __data
 548                         dataSect->atoms.insert(dataSect->atoms.end(), moveToData.begin(), moveToData.end());
 549                         // remove atoms from original sections
 550                         for (std::vector<ld::Internal::FinalSection*>::iterator sit=_state.sections.begin(); sit != _state.sections.end(); ++sit) {
 551                                 ld::Internal::FinalSection* sect = *sit;
 552                                 switch ( sect->type() ) {
 553                                         case ld::Section::typeZeroFill:
 554                                         case ld::Section::typeTentativeDefs:
 555                                                 sect->atoms.erase(std::remove_if(sect->atoms.begin(), sect->atoms.end(), InSet(moveToData)), sect->atoms.end());
 556                                                 break;
 557                                         default:
 558                                                 break;
 559                                 }
 560                         }
 561                 }
 562         }
 563
 564 }
 565
 566 void Layout::doPass()
 567 {
 568         // handle .o files that cannot have their atoms rearranged
 569         this->buildFollowOnTables();
 570
 571         // assign new ordinal value to all ordered atoms
 572         this->buildOrdinalOverrideMap();
 573
 574         // sort atoms in each section
 575         for (std::vector<ld::Internal::FinalSection*>::iterator sit=_state.sections.begin(); sit != _state.sections.end(); ++sit) {
 576                 ld::Internal::FinalSection* sect = *sit;
 577                 //fprintf(stderr, "sorting section %s\n", sect->sectionName());
 578                 std::sort(sect->atoms.begin(), sect->atoms.end(), _comparer);
 579         }
 580
 581         //fprintf(stderr, "Sorted atoms:\n");
 582         //for (std::vector<ld::Internal::FinalSection*>::iterator sit=_state.sections.begin(); sit != _state.sections.end(); ++sit) {
 583         //      ld::Internal::FinalSection* sect = *sit;
 584         //      for (std::vector<const ld::Atom*>::iterator ait=sect->atoms.begin(); ait != sect->atoms.end(); ++ait) {
 585         //              const ld::Atom* atom = *ait;
 586         //              fprintf(stderr, "\t%p\t%s\t%s\n", atom, sect->sectionName(), atom->name());
 587         //      }
 588         //}
 589
 590 }
 591
 592
 593 void doPass(const Options& opts, ld::Internal& state)
 594 {
 595         Layout layout(opts, state);
 596         layout.doPass();
 597 }
 598
 599
 600 } // namespace order_file
 601 } // namespace passes
 602 } // namespace ld