1 //===-- llvm/Support/Win64EH.h ---Win64 EH Constants-------------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file contains constants and structures used for implementing 10 // exception handling on Win64 platforms. For more information, see 11 // http://msdn.microsoft.com/en-us/library/1eyas8tf.aspx 12 // 13 //===----------------------------------------------------------------------===// 14 15 #ifndef LLVM_SUPPORT_WIN64EH_H 16 #define LLVM_SUPPORT_WIN64EH_H 17 18 #include "llvm/Support/DataTypes.h" 19 #include "llvm/Support/Endian.h" 20 21 namespace llvm { 22 namespace Win64EH { 23 24 /// UnwindOpcodes - Enumeration whose values specify a single operation in 25 /// the prolog of a function. 26 enum UnwindOpcodes { 27 // The following set of unwind opcodes is for x86_64. They are documented at 28 // https://docs.microsoft.com/en-us/cpp/build/exception-handling-x64. 29 // Some generic values from this set are used for other architectures too. 30 UOP_PushNonVol = 0, 31 UOP_AllocLarge, 32 UOP_AllocSmall, 33 UOP_SetFPReg, 34 UOP_SaveNonVol, 35 UOP_SaveNonVolBig, 36 UOP_Epilog, 37 UOP_SpareCode, 38 UOP_SaveXMM128, 39 UOP_SaveXMM128Big, 40 UOP_PushMachFrame, 41 // The following set of unwind opcodes is for ARM64. They are documented at 42 // https://docs.microsoft.com/en-us/cpp/build/arm64-exception-handling 43 UOP_AllocMedium, 44 UOP_SaveR19R20X, 45 UOP_SaveFPLRX, 46 UOP_SaveFPLR, 47 UOP_SaveReg, 48 UOP_SaveRegX, 49 UOP_SaveRegP, 50 UOP_SaveRegPX, 51 UOP_SaveLRPair, 52 UOP_SaveFReg, 53 UOP_SaveFRegX, 54 UOP_SaveFRegP, 55 UOP_SaveFRegPX, 56 UOP_SetFP, 57 UOP_AddFP, 58 UOP_Nop, 59 UOP_End, 60 UOP_SaveNext, 61 UOP_TrapFrame, 62 UOP_Context, 63 UOP_ECContext, 64 UOP_ClearUnwoundToCall, 65 UOP_PACSignLR, 66 UOP_SaveAnyRegI, 67 UOP_SaveAnyRegIP, 68 UOP_SaveAnyRegD, 69 UOP_SaveAnyRegDP, 70 UOP_SaveAnyRegQ, 71 UOP_SaveAnyRegQP, 72 UOP_SaveAnyRegIX, 73 UOP_SaveAnyRegIPX, 74 UOP_SaveAnyRegDX, 75 UOP_SaveAnyRegDPX, 76 UOP_SaveAnyRegQX, 77 UOP_SaveAnyRegQPX, 78 79 // The following set of unwind opcodes is for ARM. They are documented at 80 // https://docs.microsoft.com/en-us/cpp/build/arm-exception-handling 81 82 // Stack allocations use UOP_AllocSmall, UOP_AllocLarge from above, plus 83 // the following. AllocSmall, AllocLarge and AllocHuge represent a 16 bit 84 // instruction, while the WideAlloc* opcodes represent a 32 bit instruction. 85 // Small can represent a stack offset of 0x7f*4 (252) bytes, Medium can 86 // represent up to 0x3ff*4 (4092) bytes, Large up to 0xffff*4 (262140) bytes, 87 // and Huge up to 0xffffff*4 (67108860) bytes. 88 UOP_AllocHuge, 89 UOP_WideAllocMedium, 90 UOP_WideAllocLarge, 91 UOP_WideAllocHuge, 92 93 UOP_WideSaveRegMask, 94 UOP_SaveSP, 95 UOP_SaveRegsR4R7LR, 96 UOP_WideSaveRegsR4R11LR, 97 UOP_SaveFRegD8D15, 98 UOP_SaveRegMask, 99 UOP_SaveLR, 100 UOP_SaveFRegD0D15, 101 UOP_SaveFRegD16D31, 102 // Using UOP_Nop from above 103 UOP_WideNop, 104 // Using UOP_End from above 105 UOP_EndNop, 106 UOP_WideEndNop, 107 // A custom unspecified opcode, consisting of one or more bytes. This 108 // allows producing opcodes in the implementation defined/reserved range. 109 UOP_Custom, 110 }; 111 112 /// UnwindCode - This union describes a single operation in a function prolog, 113 /// or part thereof. 114 union UnwindCode { 115 struct { 116 uint8_t CodeOffset; 117 uint8_t UnwindOpAndOpInfo; 118 } u; 119 support::ulittle16_t FrameOffset; 120 121 uint8_t getUnwindOp() const { 122 return u.UnwindOpAndOpInfo & 0x0F; 123 } 124 uint8_t getOpInfo() const { 125 return (u.UnwindOpAndOpInfo >> 4) & 0x0F; 126 } 127 }; 128 129 enum { 130 /// UNW_ExceptionHandler - Specifies that this function has an exception 131 /// handler. 132 UNW_ExceptionHandler = 0x01, 133 /// UNW_TerminateHandler - Specifies that this function has a termination 134 /// handler. 135 UNW_TerminateHandler = 0x02, 136 /// UNW_ChainInfo - Specifies that this UnwindInfo structure is chained to 137 /// another one. 138 UNW_ChainInfo = 0x04 139 }; 140 141 /// RuntimeFunction - An entry in the table of functions with unwind info. 142 struct RuntimeFunction { 143 support::ulittle32_t StartAddress; 144 support::ulittle32_t EndAddress; 145 support::ulittle32_t UnwindInfoOffset; 146 }; 147 148 /// UnwindInfo - An entry in the exception table. 149 struct UnwindInfo { 150 uint8_t VersionAndFlags; 151 uint8_t PrologSize; 152 uint8_t NumCodes; 153 uint8_t FrameRegisterAndOffset; 154 UnwindCode UnwindCodes[1]; 155 156 uint8_t getVersion() const { 157 return VersionAndFlags & 0x07; 158 } 159 uint8_t getFlags() const { 160 return (VersionAndFlags >> 3) & 0x1f; 161 } 162 uint8_t getFrameRegister() const { 163 return FrameRegisterAndOffset & 0x0f; 164 } 165 uint8_t getFrameOffset() const { 166 return (FrameRegisterAndOffset >> 4) & 0x0f; 167 } 168 169 // The data after unwindCodes depends on flags. 170 // If UNW_ExceptionHandler or UNW_TerminateHandler is set then follows 171 // the address of the language-specific exception handler. 172 // If UNW_ChainInfo is set then follows a RuntimeFunction which defines 173 // the chained unwind info. 174 // For more information please see MSDN at: 175 // http://msdn.microsoft.com/en-us/library/ddssxxy8.aspx 176 177 /// Return pointer to language specific data part of UnwindInfo. 178 void *getLanguageSpecificData() { 179 return reinterpret_cast<void *>(&UnwindCodes[(NumCodes+1) & ~1]); 180 } 181 182 /// Return pointer to language specific data part of UnwindInfo. 183 const void *getLanguageSpecificData() const { 184 return reinterpret_cast<const void *>(&UnwindCodes[(NumCodes + 1) & ~1]); 185 } 186 187 /// Return image-relative offset of language-specific exception handler. 188 uint32_t getLanguageSpecificHandlerOffset() const { 189 return *reinterpret_cast<const support::ulittle32_t *>( 190 getLanguageSpecificData()); 191 } 192 193 /// Set image-relative offset of language-specific exception handler. 194 void setLanguageSpecificHandlerOffset(uint32_t offset) { 195 *reinterpret_cast<support::ulittle32_t *>(getLanguageSpecificData()) = 196 offset; 197 } 198 199 /// Return pointer to exception-specific data. 200 void *getExceptionData() { 201 return reinterpret_cast<void *>(reinterpret_cast<uint32_t *>( 202 getLanguageSpecificData())+1); 203 } 204 205 /// Return pointer to chained unwind info. 206 RuntimeFunction *getChainedFunctionEntry() { 207 return reinterpret_cast<RuntimeFunction *>(getLanguageSpecificData()); 208 } 209 210 /// Return pointer to chained unwind info. 211 const RuntimeFunction *getChainedFunctionEntry() const { 212 return reinterpret_cast<const RuntimeFunction *>(getLanguageSpecificData()); 213 } 214 }; 215 216 217 } // End of namespace Win64EH 218 } // End of namespace llvm 219 220 #endif 221