src/ld/Resolver.h

   1 /* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-*
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   3  * Copyright (c) 2009 Apple Inc. All rights reserved.
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   9  * Version 2.0 (the 'License'). You may not use this file except in
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  11  * http://www.opensource.apple.com/apsl/ and read it before using this
  12  * file.
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  14  * The Original Code and all software distributed under the License are
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  24
  25 #ifndef __RESOLVER_H__
  26 #define __RESOLVER_H__
  27
  28 #include <stdlib.h>
  29 #include <sys/types.h>
  30 #include <sys/stat.h>
  31 #include <sys/mman.h>
  32 #include <sys/sysctl.h>
  33 #include <fcntl.h>
  34 #include <errno.h>
  35 #include <limits.h>
  36 #include <unistd.h>
  37 #include <mach/mach_time.h>
  38 #include <mach/vm_statistics.h>
  39 #include <mach/mach_init.h>
  40 #include <mach/mach_host.h>
  41 #include <dlfcn.h>
  42 #include <mach-o/dyld.h>
  43
  44 #include <vector>
  45 #include <unordered_set>
  46
  47 #include "Options.h"
  48 #include "ld.hpp"
  49 #include "SymbolTable.h"
  50
  51
  52 namespace ld {
  53 namespace tool {
  54
  55
  56
  57
  58 class Resolver : public ld::File::AtomHandler
  59 {
  60 public:
  61                                                         Resolver(const Options& opts, InputFiles& inputs, ld::Internal& state)
  62                                                                 : _options(opts), _inputFiles(inputs), _internal(state),
  63                                                                   _symbolTable(opts, state.indirectBindingTable),
  64                                                                   _haveLLVMObjs(false),
  65                                                                   _completedInitialObjectFiles(false),
  66                                                                   _ltoCodeGenFinished(false),
  67                                                                   _haveAliases(false) {}
  68
  69
  70                 virtual void            doAtom(const ld::Atom&);
  71                 virtual void            doFile(const class File&);
  72
  73                 void                            resolve();
  74
  75
  76 private:
  77         struct WhyLiveBackChain
  78         {
  79                 WhyLiveBackChain*       previous;
  80                 const ld::Atom*         referer;
  81         };
  82
  83         void                                    initializeState();
  84         void                                    buildAtomList();
  85         void                                    addInitialUndefines();
  86         void                                    deadStripOptimize(bool force=false);
  87         void                                    resolveUndefines();
  88         void                                    checkUndefines(bool force=false);
  89         void                                    checkDylibSymbolCollisions();
  90         void                                    tentativeOverrideOfDylib(ld::Atom&);
  91         void                                    fillInInternalState();
  92         void                                    fillInHelpersInInternalState();
  93         void                                    removeCoalescedAwayAtoms();
  94         void                                    syncAliases();
  95         void                                    fillInEntryPoint();
  96         void                                    linkTimeOptimize();
  97         void                                    convertReferencesToIndirect(const ld::Atom& atom);
  98         const ld::Atom*                 entryPoint(bool searchArchives);
  99         void                                    markLive(const ld::Atom& atom, WhyLiveBackChain* previous);
 100         bool                                    isDtraceProbe(ld::Fixup::Kind kind);
 101         void                                    liveUndefines(std::vector<const char*>&);
 102         void                                    remainingUndefines(std::vector<const char*>&);
 103         bool                                    printReferencedBy(const char* name, SymbolTable::IndirectBindingSlot slot);
 104         void                                    tweakWeakness();
 105         void                                    doLinkerOption(const std::vector<const char*>& linkerOption, const char* fileName);
 106         void                                    dumpAtoms();
 107
 108         typedef std::unordered_set<const char*, CStringHash, CStringEquals>  StringSet;
 109
 110         class NotLive {
 111         public:
 112                 bool operator()(const ld::Atom* atom) const {
 113                         return ! (atom->live() || atom->dontDeadStrip());
 114                 }
 115         };
 116
 117         class AtomCoalescedAway {
 118         public:
 119                 bool operator()(const ld::Atom* atom) const {
 120                         return atom->coalescedAway();
 121                 }
 122         };
 123
 124         const Options&                                  _options;
 125         InputFiles&                                             _inputFiles;
 126         ld::Internal&                                   _internal;
 127         std::vector<const ld::Atom*>    _atoms;
 128         std::set<const ld::Atom*>               _deadStripRoots;
 129         std::vector<const ld::Atom*>    _dontDeadStripIfReferencesLive;
 130         std::vector<const ld::Atom*>    _atomsWithUnresolvedReferences;
 131         std::vector<const class AliasAtom*>     _aliasesFromCmdLine;
 132         SymbolTable                                             _symbolTable;
 133         bool                                                    _haveLLVMObjs;
 134         bool                                                    _completedInitialObjectFiles;
 135         bool                                                    _ltoCodeGenFinished;
 136         bool                                                    _haveAliases;
 137 };
 138
 139
 140 class DeadStripResolver
 141 {
 142 public:
 143
 144
 145 private:
 146
 147 };
 148
 149 } // namespace tool
 150 } // namespace ld
 151
 152
 153
 154 #endif // __RESOLVER_H__