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
_Unwind_GetGR(struct _Unwind_Context * context,int index)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
_Unwind_SetGR(struct _Unwind_Context * context,int index,uintptr_t value)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
_Unwind_GetIP(struct _Unwind_Context * context)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
_Unwind_SetIP(struct _Unwind_Context * context,uintptr_t value)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