1 //===- ELFObjectWriter.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 #ifndef MCLD_LD_ELFOBJWRITER_H 10 #define MCLD_LD_ELFOBJWRITER_H 11 #include <mcld/LD/ObjectWriter.h> 12 #include <cassert> 13 14 #include <mcld/Support/FileOutputBuffer.h> 15 16 namespace mcld { 17 18 class EhFrame; 19 class Module; 20 class LinkerConfig; 21 class GNULDBackend; 22 class FragmentLinker; 23 class Relocation; 24 class LDSection; 25 class SectionData; 26 class RelocData; 27 class Output; 28 29 /** \class ELFObjectWriter 30 * \brief ELFObjectWriter writes the target-independent parts of object files. 31 * ELFObjectWriter reads a MCLDFile and writes into raw_ostream 32 * 33 */ 34 class ELFObjectWriter : public ObjectWriter 35 { 36 public: 37 ELFObjectWriter(GNULDBackend& pBackend, const LinkerConfig& pConfig); 38 39 ~ELFObjectWriter(); 40 41 std::error_code writeObject(Module& pModule, FileOutputBuffer& pOutput); 42 43 size_t getOutputSize(const Module& pModule) const; 44 45 private: 46 void writeSection(Module& pModule, 47 FileOutputBuffer& pOutput, LDSection *section); 48 49 GNULDBackend& target() { return m_Backend; } 50 51 const GNULDBackend& target() const { return m_Backend; } 52 53 // writeELFHeader - emit ElfXX_Ehdr 54 template<size_t SIZE> 55 void writeELFHeader(const LinkerConfig& pConfig, 56 const Module& pModule, 57 FileOutputBuffer& pOutput) const; 58 59 uint64_t getEntryPoint(const LinkerConfig& pConfig, 60 const Module& pModule) const; 61 62 // emitSectionHeader - emit ElfXX_Shdr 63 template<size_t SIZE> 64 void emitSectionHeader(const Module& pModule, 65 const LinkerConfig& pConfig, 66 FileOutputBuffer& pOutput) const; 67 68 // emitProgramHeader - emit ElfXX_Phdr 69 template<size_t SIZE> 70 void emitProgramHeader(FileOutputBuffer& pOutput) const; 71 72 // emitShStrTab - emit .shstrtab 73 void emitShStrTab(const LDSection& pShStrTab, 74 const Module& pModule, 75 FileOutputBuffer& pOutput); 76 77 void emitSectionData(const LDSection& pSection, MemoryRegion& pRegion) const; 78 79 void emitEhFrame(Module& pModule, 80 EhFrame& pFrame, MemoryRegion& pRegion) const; 81 82 void emitRelocation(const LinkerConfig& pConfig, 83 const LDSection& pSection, 84 MemoryRegion& pRegion) const; 85 86 // emitRel - emit ElfXX_Rel 87 template<size_t SIZE> 88 void emitRel(const LinkerConfig& pConfig, 89 const RelocData& pRelocData, 90 MemoryRegion& pRegion) const; 91 92 // emitRela - emit ElfXX_Rela 93 template<size_t SIZE> 94 void emitRela(const LinkerConfig& pConfig, 95 const RelocData& pRelocData, 96 MemoryRegion& pRegion) const; 97 98 // getSectEntrySize - compute ElfXX_Shdr::sh_entsize 99 template<size_t SIZE> 100 uint64_t getSectEntrySize(const LDSection& pSection) const; 101 102 // getSectLink - compute ElfXX_Shdr::sh_link 103 uint64_t getSectLink(const LDSection& pSection, 104 const LinkerConfig& pConfig) const; 105 106 // getSectInfo - compute ElfXX_Shdr::sh_info 107 uint64_t getSectInfo(const LDSection& pSection) const; 108 109 template<size_t SIZE> 110 uint64_t getLastStartOffset(const Module& pModule) const 111 { 112 assert(0 && "Call invalid ELFObjectWriter::getLastStartOffset"); 113 return 0; 114 } 115 116 void emitSectionData(const SectionData& pSD, MemoryRegion& pRegion) const; 117 118 private: 119 GNULDBackend& m_Backend; 120 121 const LinkerConfig& m_Config; 122 }; 123 124 template<> 125 uint64_t ELFObjectWriter::getLastStartOffset<32>(const Module& pModule) const; 126 127 template<> 128 uint64_t ELFObjectWriter::getLastStartOffset<64>(const Module& pModule) const; 129 130 } // namespace of mcld 131 132 #endif 133 134
