1 //===----------------------------------------------------------------------===// 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 // C++ ABI Level 1 ABI documented at: 9 // https://github.com/ARM-software/abi-aa/blob/main/ehabi32/ehabi32.rst 10 // 11 //===----------------------------------------------------------------------===// 12 13 #ifndef __ARM_EHABI_UNWIND_H__ 14 #define __ARM_EHABI_UNWIND_H__ 15 16 typedef uint32_t _Unwind_State; 17 18 static const _Unwind_State _US_VIRTUAL_UNWIND_FRAME = 0; 19 static const _Unwind_State _US_UNWIND_FRAME_STARTING = 1; 20 static const _Unwind_State _US_UNWIND_FRAME_RESUME = 2; 21 static const _Unwind_State _US_ACTION_MASK = 3; 22 /* Undocumented flag for force unwinding. */ 23 static const _Unwind_State _US_FORCE_UNWIND = 8; 24 25 typedef uint32_t _Unwind_EHT_Header; 26 /* 27 * gcc_personality_v0 references 'struct _Unwind_Exception' all over the place. 28 * Nothing in libunwind cares about 'struct _Unwind_Control_Block,' so make it 29 * the alias of struct _Unwind_Exception, instead of the other way around. 30 */ 31 struct _Unwind_Exception; 32 typedef struct _Unwind_Exception _Unwind_Exception; 33 typedef struct _Unwind_Exception _Unwind_Control_Block; /* Alias */ 34 typedef uint8_t _Unwind_Exception_Class[8]; 35 36 struct _Unwind_Exception { 37 _Unwind_Exception_Class exception_class; 38 void (*exception_cleanup)(_Unwind_Reason_Code, _Unwind_Control_Block*); 39 40 /* Unwinder cache, private fields for the unwinder's use */ 41 struct { 42 uint32_t reserved1; /* init reserved1 to 0, then don't touch */ 43 uint32_t reserved2; 44 uint32_t reserved3; 45 uint32_t reserved4; 46 uint32_t reserved5; 47 } unwinder_cache; 48 49 /* Propagation barrier cache (valid after phase 1): */ 50 struct { 51 uint32_t sp; 52 uint32_t bitpattern[5]; 53 } barrier_cache; 54 55 /* Cleanup cache (preserved over cleanup): */ 56 struct { 57 uint32_t bitpattern[4]; 58 } cleanup_cache; 59 60 /* Pr cache (for pr's benefit): */ 61 struct { 62 uint32_t fnstart; /* function start address */ 63 _Unwind_EHT_Header* ehtp; /* pointer to EHT entry header word */ 64 uint32_t additional; 65 uint32_t reserved1; 66 } pr_cache; 67 68 long long int :0; /* Enforce the 8-byte alignment */ 69 } __attribute__((__aligned__(8))); 70 71 typedef _Unwind_Reason_Code (*_Unwind_Personality_Fn)( 72 _Unwind_State state, _Unwind_Exception *exceptionObject, 73 struct _Unwind_Context *context); 74 75 #ifdef __cplusplus 76 extern "C" { 77 #endif 78 79 // 80 // The following are the base functions documented by the C++ ABI 81 // 82 #ifdef __USING_SJLJ_EXCEPTIONS__ 83 extern _Unwind_Reason_Code 84 _Unwind_SjLj_RaiseException(_Unwind_Exception *exception_object); 85 extern void _Unwind_SjLj_Resume(_Unwind_Exception *exception_object); 86 #else 87 extern _Unwind_Reason_Code 88 _Unwind_RaiseException(_Unwind_Exception *exception_object); 89 extern void _Unwind_Resume(_Unwind_Exception *exception_object); 90 #endif 91 extern void _Unwind_DeleteException(_Unwind_Exception *exception_object); 92 93 typedef enum { 94 _UVRSC_CORE = 0, /* integer register */ 95 _UVRSC_VFP = 1, /* vfp */ 96 _UVRSC_WMMXD = 3, /* Intel WMMX data register */ 97 _UVRSC_WMMXC = 4, /* Intel WMMX control register */ 98 _UVRSC_PSEUDO = 5 /* Special purpose pseudo register */ 99 } _Unwind_VRS_RegClass; 100 101 typedef enum { 102 _UVRSD_UINT32 = 0, 103 _UVRSD_VFPX = 1, 104 _UVRSD_UINT64 = 3, 105 _UVRSD_FLOAT = 4, 106 _UVRSD_DOUBLE = 5 107 } _Unwind_VRS_DataRepresentation; 108 109 typedef enum { 110 _UVRSR_OK = 0, 111 _UVRSR_NOT_IMPLEMENTED = 1, 112 _UVRSR_FAILED = 2 113 } _Unwind_VRS_Result; 114 115 extern void _Unwind_Complete(_Unwind_Exception* exception_object); 116 117 extern _Unwind_VRS_Result 118 _Unwind_VRS_Get(_Unwind_Context *context, _Unwind_VRS_RegClass regclass, 119 uint32_t regno, _Unwind_VRS_DataRepresentation representation, 120 void *valuep); 121 122 extern _Unwind_VRS_Result 123 _Unwind_VRS_Set(_Unwind_Context *context, _Unwind_VRS_RegClass regclass, 124 uint32_t regno, _Unwind_VRS_DataRepresentation representation, 125 void *valuep); 126 127 extern _Unwind_VRS_Result 128 _Unwind_VRS_Pop(_Unwind_Context *context, _Unwind_VRS_RegClass regclass, 129 uint32_t discriminator, 130 _Unwind_VRS_DataRepresentation representation); 131 132 #if defined(_LIBUNWIND_UNWIND_LEVEL1_EXTERNAL_LINKAGE) 133 #define _LIBUNWIND_EXPORT_UNWIND_LEVEL1 extern 134 #else 135 #define _LIBUNWIND_EXPORT_UNWIND_LEVEL1 static __inline__ 136 #endif 137 138 // These are de facto helper functions for ARM, which delegate the function 139 // calls to _Unwind_VRS_Get/Set(). These are not a part of ARM EHABI 140 // specification, thus these function MUST be inlined. Please don't replace 141 // these with the "extern" function declaration; otherwise, the program 142 // including this <unwind.h> header won't be ABI compatible and will result in 143 // link error when we are linking the program with libgcc. 144 145 _LIBUNWIND_EXPORT_UNWIND_LEVEL1 146 uintptr_t _Unwind_GetGR(struct _Unwind_Context *context, int index) { 147 uintptr_t value = 0; 148 _Unwind_VRS_Get(context, _UVRSC_CORE, (uint32_t)index, _UVRSD_UINT32, &value); 149 return value; 150 } 151 152 _LIBUNWIND_EXPORT_UNWIND_LEVEL1 153 void _Unwind_SetGR(struct _Unwind_Context *context, int index, 154 uintptr_t value) { 155 _Unwind_VRS_Set(context, _UVRSC_CORE, (uint32_t)index, _UVRSD_UINT32, &value); 156 } 157 158 _LIBUNWIND_EXPORT_UNWIND_LEVEL1 159 uintptr_t _Unwind_GetIP(struct _Unwind_Context *context) { 160 // remove the thumb-bit before returning 161 return _Unwind_GetGR(context, 15) & (~(uintptr_t)0x1); 162 } 163 164 _LIBUNWIND_EXPORT_UNWIND_LEVEL1 165 void _Unwind_SetIP(struct _Unwind_Context *context, uintptr_t value) { 166 uintptr_t thumb_bit = _Unwind_GetGR(context, 15) & ((uintptr_t)0x1); 167 _Unwind_SetGR(context, 15, value | thumb_bit); 168 } 169 170 #ifdef __cplusplus 171 } 172 #endif 173 174 #endif // __ARM_EHABI_UNWIND_H__ 175