1 //===- EhFrameReader.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_EHFRAMEREADER_H_ 10 #define MCLD_LD_EHFRAMEREADER_H_ 11 #include "mcld/LD/EhFrame.h" 12 13 #include <llvm/ADT/StringRef.h> 14 #include <llvm/Support/DataTypes.h> 15 16 namespace mcld { 17 18 class Input; 19 class LDSection; 20 21 /** \class EhFrameReader 22 * \brief EhFrameReader reads .eh_frame section 23 * 24 * EhFrameReader is responsible to parse the input eh_frame sections and create 25 * the corresponding CIE and FDE entries. 26 */ 27 class EhFrameReader { 28 public: 29 typedef const char* ConstAddress; 30 typedef char* Address; 31 32 public: 33 /// read - read an .eh_frame section and create the corresponding 34 /// CIEs and FDEs 35 /// @param pInput [in] the Input contains this eh_frame 36 /// @param pEhFrame [inout] the input eh_frame 37 /// @return if we read all CIEs and FDEs successfully, return true. Otherwise, 38 /// return false; 39 template <size_t BITCLASS, bool SAME_ENDIAN> 40 bool read(Input& pInput, EhFrame& pEhFrame); 41 42 private: 43 enum TokenKind { CIE, FDE, Terminator, Unknown, NumOfTokenKinds }; 44 45 enum State { Q0, Q1, Accept, NumOfStates = 2, Reject = -1 }; 46 47 struct Token { 48 TokenKind kind; 49 size_t file_off; 50 size_t data_off; 51 uint64_t size; 52 }; 53 54 /// Action - the transition function of autometa. 55 /// @param pEhFrame - the output .eh_frame section 56 /// @param pSection - the input .eh_frame section 57 /// @param pRegion - the memory region that needs to handle with. 58 typedef bool (*Action)(EhFrame& pEhFrame, 59 llvm::StringRef pRegion, 60 const Token& pToken); 61 62 private: 63 /// scan - scan pData from pHandler for a token. 64 template <bool SAME_ENDIAN> 65 Token scan(ConstAddress pHandler, 66 uint64_t pOffset, 67 llvm::StringRef pData) const; 68 69 static bool addCIE(EhFrame& pEhFrame, 70 llvm::StringRef pRegion, 71 const Token& pToken); 72 73 static bool addFDE(EhFrame& pEhFrame, 74 llvm::StringRef pRegion, 75 const Token& pToken); 76 77 static bool addTerm(EhFrame& pEhFrame, 78 llvm::StringRef pRegion, 79 const Token& pToken); 80 81 static bool reject(EhFrame& pEhFrame, 82 llvm::StringRef pRegion, 83 const Token& pToken); 84 }; 85 86 template <> 87 bool EhFrameReader::read<32, true>(Input& pInput, EhFrame& pEhFrame); 88 89 template <> 90 EhFrameReader::Token EhFrameReader::scan<true>(ConstAddress pHandler, 91 uint64_t pOffset, 92 llvm::StringRef pData) const; 93 94 } // namespace mcld 95 96 #endif // MCLD_LD_EHFRAMEREADER_H_ 97
