1 //===-- llvm/Support/Win64EH.h ---Win64 EH Constants-------------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file contains constants and structures used for implementing 11 // exception handling on Win64 platforms. For more information, see 12 // http://msdn.microsoft.com/en-us/library/1eyas8tf.aspx 13 // 14 //===----------------------------------------------------------------------===// 15 16 #ifndef LLVM_SUPPORT_WIN64EH_H 17 #define LLVM_SUPPORT_WIN64EH_H 18 19 #include "llvm/Support/DataTypes.h" 20 #include "llvm/Support/Endian.h" 21 22 namespace llvm { 23 namespace Win64EH { 24 25 /// UnwindOpcodes - Enumeration whose values specify a single operation in 26 /// the prolog of a function. 27 enum UnwindOpcodes { 28 UOP_PushNonVol = 0, 29 UOP_AllocLarge, 30 UOP_AllocSmall, 31 UOP_SetFPReg, 32 UOP_SaveNonVol, 33 UOP_SaveNonVolBig, 34 UOP_SaveXMM128 = 8, 35 UOP_SaveXMM128Big, 36 UOP_PushMachFrame 37 }; 38 39 /// UnwindCode - This union describes a single operation in a function prolog, 40 /// or part thereof. 41 union UnwindCode { 42 struct { 43 uint8_t CodeOffset; 44 uint8_t UnwindOpAndOpInfo; 45 } u; 46 support::ulittle16_t FrameOffset; 47 getUnwindOp()48 uint8_t getUnwindOp() const { 49 return u.UnwindOpAndOpInfo & 0x0F; 50 } getOpInfo()51 uint8_t getOpInfo() const { 52 return (u.UnwindOpAndOpInfo >> 4) & 0x0F; 53 } 54 }; 55 56 enum { 57 /// UNW_ExceptionHandler - Specifies that this function has an exception 58 /// handler. 59 UNW_ExceptionHandler = 0x01, 60 /// UNW_TerminateHandler - Specifies that this function has a termination 61 /// handler. 62 UNW_TerminateHandler = 0x02, 63 /// UNW_ChainInfo - Specifies that this UnwindInfo structure is chained to 64 /// another one. 65 UNW_ChainInfo = 0x04 66 }; 67 68 /// RuntimeFunction - An entry in the table of functions with unwind info. 69 struct RuntimeFunction { 70 support::ulittle32_t StartAddress; 71 support::ulittle32_t EndAddress; 72 support::ulittle32_t UnwindInfoOffset; 73 }; 74 75 /// UnwindInfo - An entry in the exception table. 76 struct UnwindInfo { 77 uint8_t VersionAndFlags; 78 uint8_t PrologSize; 79 uint8_t NumCodes; 80 uint8_t FrameRegisterAndOffset; 81 UnwindCode UnwindCodes[1]; 82 getVersionUnwindInfo83 uint8_t getVersion() const { 84 return VersionAndFlags & 0x07; 85 } getFlagsUnwindInfo86 uint8_t getFlags() const { 87 return (VersionAndFlags >> 3) & 0x1f; 88 } getFrameRegisterUnwindInfo89 uint8_t getFrameRegister() const { 90 return FrameRegisterAndOffset & 0x0f; 91 } getFrameOffsetUnwindInfo92 uint8_t getFrameOffset() const { 93 return (FrameRegisterAndOffset >> 4) & 0x0f; 94 } 95 96 // The data after unwindCodes depends on flags. 97 // If UNW_ExceptionHandler or UNW_TerminateHandler is set then follows 98 // the address of the language-specific exception handler. 99 // If UNW_ChainInfo is set then follows a RuntimeFunction which defines 100 // the chained unwind info. 101 // For more information please see MSDN at: 102 // http://msdn.microsoft.com/en-us/library/ddssxxy8.aspx 103 104 /// \brief Return pointer to language specific data part of UnwindInfo. getLanguageSpecificDataUnwindInfo105 void *getLanguageSpecificData() { 106 return reinterpret_cast<void *>(&UnwindCodes[(NumCodes+1) & ~1]); 107 } 108 109 /// \brief Return pointer to language specific data part of UnwindInfo. getLanguageSpecificDataUnwindInfo110 const void *getLanguageSpecificData() const { 111 return reinterpret_cast<const void *>(&UnwindCodes[(NumCodes + 1) & ~1]); 112 } 113 114 /// \brief Return image-relative offset of language-specific exception handler. getLanguageSpecificHandlerOffsetUnwindInfo115 uint32_t getLanguageSpecificHandlerOffset() const { 116 return *reinterpret_cast<const support::ulittle32_t *>( 117 getLanguageSpecificData()); 118 } 119 120 /// \brief Set image-relative offset of language-specific exception handler. setLanguageSpecificHandlerOffsetUnwindInfo121 void setLanguageSpecificHandlerOffset(uint32_t offset) { 122 *reinterpret_cast<support::ulittle32_t *>(getLanguageSpecificData()) = 123 offset; 124 } 125 126 /// \brief Return pointer to exception-specific data. getExceptionDataUnwindInfo127 void *getExceptionData() { 128 return reinterpret_cast<void *>(reinterpret_cast<uint32_t *>( 129 getLanguageSpecificData())+1); 130 } 131 132 /// \brief Return pointer to chained unwind info. getChainedFunctionEntryUnwindInfo133 RuntimeFunction *getChainedFunctionEntry() { 134 return reinterpret_cast<RuntimeFunction *>(getLanguageSpecificData()); 135 } 136 137 /// \brief Return pointer to chained unwind info. getChainedFunctionEntryUnwindInfo138 const RuntimeFunction *getChainedFunctionEntry() const { 139 return reinterpret_cast<const RuntimeFunction *>(getLanguageSpecificData()); 140 } 141 }; 142 143 144 } // End of namespace Win64EH 145 } // End of namespace llvm 146 147 #endif 148