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 // The following set of unwind opcodes is for ARM64. They are documented at 38 // https://docs.microsoft.com/en-us/cpp/build/arm64-exception-handling 39 UOP_AllocMedium, 40 UOP_SaveFPLRX, 41 UOP_SaveFPLR, 42 UOP_SaveReg, 43 UOP_SaveRegX, 44 UOP_SaveRegP, 45 UOP_SaveRegPX, 46 UOP_SaveFReg, 47 UOP_SaveFRegX, 48 UOP_SaveFRegP, 49 UOP_SaveFRegPX, 50 UOP_SetFP, 51 UOP_AddFP, 52 UOP_Nop, 53 UOP_End 54 }; 55 56 /// UnwindCode - This union describes a single operation in a function prolog, 57 /// or part thereof. 58 union UnwindCode { 59 struct { 60 uint8_t CodeOffset; 61 uint8_t UnwindOpAndOpInfo; 62 } u; 63 support::ulittle16_t FrameOffset; 64 getUnwindOp()65 uint8_t getUnwindOp() const { 66 return u.UnwindOpAndOpInfo & 0x0F; 67 } getOpInfo()68 uint8_t getOpInfo() const { 69 return (u.UnwindOpAndOpInfo >> 4) & 0x0F; 70 } 71 }; 72 73 enum { 74 /// UNW_ExceptionHandler - Specifies that this function has an exception 75 /// handler. 76 UNW_ExceptionHandler = 0x01, 77 /// UNW_TerminateHandler - Specifies that this function has a termination 78 /// handler. 79 UNW_TerminateHandler = 0x02, 80 /// UNW_ChainInfo - Specifies that this UnwindInfo structure is chained to 81 /// another one. 82 UNW_ChainInfo = 0x04 83 }; 84 85 /// RuntimeFunction - An entry in the table of functions with unwind info. 86 struct RuntimeFunction { 87 support::ulittle32_t StartAddress; 88 support::ulittle32_t EndAddress; 89 support::ulittle32_t UnwindInfoOffset; 90 }; 91 92 /// UnwindInfo - An entry in the exception table. 93 struct UnwindInfo { 94 uint8_t VersionAndFlags; 95 uint8_t PrologSize; 96 uint8_t NumCodes; 97 uint8_t FrameRegisterAndOffset; 98 UnwindCode UnwindCodes[1]; 99 getVersionUnwindInfo100 uint8_t getVersion() const { 101 return VersionAndFlags & 0x07; 102 } getFlagsUnwindInfo103 uint8_t getFlags() const { 104 return (VersionAndFlags >> 3) & 0x1f; 105 } getFrameRegisterUnwindInfo106 uint8_t getFrameRegister() const { 107 return FrameRegisterAndOffset & 0x0f; 108 } getFrameOffsetUnwindInfo109 uint8_t getFrameOffset() const { 110 return (FrameRegisterAndOffset >> 4) & 0x0f; 111 } 112 113 // The data after unwindCodes depends on flags. 114 // If UNW_ExceptionHandler or UNW_TerminateHandler is set then follows 115 // the address of the language-specific exception handler. 116 // If UNW_ChainInfo is set then follows a RuntimeFunction which defines 117 // the chained unwind info. 118 // For more information please see MSDN at: 119 // http://msdn.microsoft.com/en-us/library/ddssxxy8.aspx 120 121 /// Return pointer to language specific data part of UnwindInfo. getLanguageSpecificDataUnwindInfo122 void *getLanguageSpecificData() { 123 return reinterpret_cast<void *>(&UnwindCodes[(NumCodes+1) & ~1]); 124 } 125 126 /// Return pointer to language specific data part of UnwindInfo. getLanguageSpecificDataUnwindInfo127 const void *getLanguageSpecificData() const { 128 return reinterpret_cast<const void *>(&UnwindCodes[(NumCodes + 1) & ~1]); 129 } 130 131 /// Return image-relative offset of language-specific exception handler. getLanguageSpecificHandlerOffsetUnwindInfo132 uint32_t getLanguageSpecificHandlerOffset() const { 133 return *reinterpret_cast<const support::ulittle32_t *>( 134 getLanguageSpecificData()); 135 } 136 137 /// Set image-relative offset of language-specific exception handler. setLanguageSpecificHandlerOffsetUnwindInfo138 void setLanguageSpecificHandlerOffset(uint32_t offset) { 139 *reinterpret_cast<support::ulittle32_t *>(getLanguageSpecificData()) = 140 offset; 141 } 142 143 /// Return pointer to exception-specific data. getExceptionDataUnwindInfo144 void *getExceptionData() { 145 return reinterpret_cast<void *>(reinterpret_cast<uint32_t *>( 146 getLanguageSpecificData())+1); 147 } 148 149 /// Return pointer to chained unwind info. getChainedFunctionEntryUnwindInfo150 RuntimeFunction *getChainedFunctionEntry() { 151 return reinterpret_cast<RuntimeFunction *>(getLanguageSpecificData()); 152 } 153 154 /// Return pointer to chained unwind info. getChainedFunctionEntryUnwindInfo155 const RuntimeFunction *getChainedFunctionEntry() const { 156 return reinterpret_cast<const RuntimeFunction *>(getLanguageSpecificData()); 157 } 158 }; 159 160 161 } // End of namespace Win64EH 162 } // End of namespace llvm 163 164 #endif 165