1 //===- ObjectLinker.h -----------------------------------------------------===// 2 // 3 // The MCLinker Project 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // ObjectLinker plays the same role as GNU collect2 to prepare all implicit 11 // parameters for FragmentLinker. 12 // 13 //===----------------------------------------------------------------------===// 14 #ifndef MCLD_OBJECT_OBJECT_LINKER_H 15 #define MCLD_OBJECT_OBJECT_LINKER_H 16 #ifdef ENABLE_UNITTEST 17 #include <gtest.h> 18 #endif 19 #include <stddef.h> 20 21 namespace mcld { 22 23 class Module; 24 class LinkerConfig; 25 class IRBuilder; 26 class FragmentLinker; 27 class TargetLDBackend; 28 class MemoryArea; 29 class MemoryAreaFactory; 30 class ObjectReader; 31 class DynObjReader; 32 class ArchiveReader; 33 class GroupReader; 34 class BinaryReader; 35 class ObjectWriter; 36 class DynObjWriter; 37 class ExecWriter; 38 class BinaryWriter; 39 40 /** \class ObjectLinker 41 * \brief ObjectLinker prepares parameters for FragmentLinker. 42 */ 43 class ObjectLinker 44 { 45 public: 46 ObjectLinker(const LinkerConfig& pConfig, 47 TargetLDBackend& pLDBackend); 48 49 ~ObjectLinker(); 50 51 void setup(Module& pModule, IRBuilder& pBuilder); 52 53 /// initFragmentLinker - initialize FragmentLinker 54 /// Connect all components in FragmentLinker 55 bool initFragmentLinker(); 56 57 /// initStdSections - initialize standard sections of the output file. 58 bool initStdSections(); 59 60 /// normalize - normalize the input files 61 void normalize(); 62 63 /// linkable - check the linkability of current LinkerConfig 64 /// Check list: 65 /// - check the Attributes are not violate the constaint 66 /// - check every Input has a correct Attribute 67 bool linkable() const; 68 69 /// readRelocations - read all relocation entries 70 bool readRelocations(); 71 72 /// mergeSections - put allinput sections into output sections 73 bool mergeSections(); 74 75 /// allocateCommonSymobols - allocate fragments for common symbols to the 76 /// corresponding sections 77 bool allocateCommonSymbols(); 78 79 /// addStandardSymbols - shared object and executable files need some 80 /// standard symbols 81 /// @return if there are some input symbols with the same name to the 82 /// standard symbols, return false 83 bool addStandardSymbols(); 84 85 /// addTargetSymbols - some targets, such as MIPS and ARM, need some 86 /// target-dependent symbols 87 /// @return if there are some input symbols with the same name to the 88 /// target symbols, return false 89 bool addTargetSymbols(); 90 91 /// addScriptSymbols - define symbols from the command line option or linker 92 /// scripts. 93 bool addScriptSymbols(); 94 95 /// scanRelocations - scan all relocation entries by output symbols. 96 bool scanRelocations(); 97 98 /// initStubs - initialize stub-related stuff. 99 bool initStubs(); 100 101 /// prelayout - help backend to do some modification before layout 102 bool prelayout(); 103 104 /// layout - linearly layout all output sections and reserve some space 105 /// for GOT/PLT 106 /// Because we do not support instruction relaxing in this early version, 107 /// if there is a branch can not jump to its target, we return false 108 /// directly 109 bool layout(); 110 111 /// postlayout - help backend to do some modification after layout 112 bool postlayout(); 113 114 /// relocate - applying relocation entries and create relocation 115 /// section in the output files 116 /// Create relocation section, asking TargetLDBackend to 117 /// read the relocation information into RelocationEntry 118 /// and push_back into the relocation section 119 bool relocation(); 120 121 /// finalizeSymbolValue - finalize the symbol value 122 bool finalizeSymbolValue(); 123 124 /// emitOutput - emit the output file. 125 bool emitOutput(MemoryArea& pOutput); 126 127 /// postProcessing - do modificatiion after all processes 128 bool postProcessing(MemoryArea& pOutput); 129 130 /// getLinker - get internal FragmentLinker object getLinker()131 const FragmentLinker* getLinker() const { return m_pLinker; } getLinker()132 FragmentLinker* getLinker() { return m_pLinker; } 133 134 /// hasInitLinker - has Linker been initialized? hasInitLinker()135 bool hasInitLinker() const 136 { return (NULL != m_pLinker); } 137 138 // ----- readers and writers ----- // getObjectReader()139 const ObjectReader* getObjectReader () const { return m_pObjectReader; } getObjectReader()140 ObjectReader* getObjectReader () { return m_pObjectReader; } 141 getDynObjReader()142 const DynObjReader* getDynObjReader () const { return m_pDynObjReader; } getDynObjReader()143 DynObjReader* getDynObjReader () { return m_pDynObjReader; } 144 getArchiveReader()145 const ArchiveReader* getArchiveReader() const { return m_pArchiveReader; } getArchiveReader()146 ArchiveReader* getArchiveReader() { return m_pArchiveReader; } 147 getGroupReader()148 const GroupReader* getGroupReader () const { return m_pGroupReader; } getGroupReader()149 GroupReader* getGroupReader () { return m_pGroupReader; } 150 getBinaryReader()151 const BinaryReader* getBinaryReader () const { return m_pBinaryReader; } getBinaryReader()152 BinaryReader* getBinaryReader () { return m_pBinaryReader; } 153 getWriter()154 const ObjectWriter* getWriter () const { return m_pWriter; } getWriter()155 ObjectWriter* getWriter () { return m_pWriter; } 156 157 private: 158 const LinkerConfig& m_Config; 159 FragmentLinker* m_pLinker; 160 Module* m_pModule; 161 IRBuilder* m_pBuilder; 162 163 TargetLDBackend &m_LDBackend; 164 165 // ----- readers and writers ----- // 166 ObjectReader* m_pObjectReader; 167 DynObjReader* m_pDynObjReader; 168 ArchiveReader* m_pArchiveReader; 169 GroupReader* m_pGroupReader; 170 BinaryReader* m_pBinaryReader; 171 ObjectWriter* m_pWriter; 172 }; 173 174 } // end namespace mcld 175 #endif 176