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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
16typedef uint32_t _Unwind_State;
17
18static const _Unwind_State _US_VIRTUAL_UNWIND_FRAME = 0;
19static const _Unwind_State _US_UNWIND_FRAME_STARTING = 1;
20static const _Unwind_State _US_UNWIND_FRAME_RESUME = 2;
21static const _Unwind_State _US_ACTION_MASK = 3;
22/* Undocumented flag for force unwinding. */
23static const _Unwind_State _US_FORCE_UNWIND = 8;
24
25typedef uint32_t _Unwind_EHT_Header;
26
27struct _Unwind_Control_Block;
28typedef struct _Unwind_Control_Block _Unwind_Control_Block;
29#define _Unwind_Exception _Unwind_Control_Block /* Alias */
30typedef uint8_t _Unwind_Exception_Class[8];
31
32struct _Unwind_Control_Block {
33 _Unwind_Exception_Class exception_class;
34 void (*exception_cleanup)(_Unwind_Reason_Code, _Unwind_Control_Block*);
35
36 /* Unwinder cache, private fields for the unwinder's use */
37 struct {
38 uint32_t reserved1; /* init reserved1 to 0, then don't touch */
39 uint32_t reserved2;
40 uint32_t reserved3;
41 uint32_t reserved4;
42 uint32_t reserved5;
43 } unwinder_cache;
44
45 /* Propagation barrier cache (valid after phase 1): */
46 struct {
47 uint32_t sp;
48 uint32_t bitpattern[5];
49 } barrier_cache;
50
51 /* Cleanup cache (preserved over cleanup): */
52 struct {
53 uint32_t bitpattern[4];
54 } cleanup_cache;
55
56 /* Pr cache (for pr's benefit): */
57 struct {
58 uint32_t fnstart; /* function start address */
59 _Unwind_EHT_Header* ehtp; /* pointer to EHT entry header word */
60 uint32_t additional;
61 uint32_t reserved1;
62 } pr_cache;
63
64 long long int :0; /* Enforce the 8-byte alignment */
65} __attribute__((__aligned__(8)));
66
67typedef _Unwind_Reason_Code (*_Unwind_Personality_Fn)(
68 _Unwind_State state, _Unwind_Exception *exceptionObject,
69 struct _Unwind_Context *context);
70
71#ifdef __cplusplus
72extern "C" {
73#endif
74
75//
76// The following are the base functions documented by the C++ ABI
77//
78#ifdef __USING_SJLJ_EXCEPTIONS__
79extern _Unwind_Reason_Code
80 _Unwind_SjLj_RaiseException(_Unwind_Exception *exception_object);
81extern void _Unwind_SjLj_Resume(_Unwind_Exception *exception_object);
82#else
83extern _Unwind_Reason_Code
84 _Unwind_RaiseException(_Unwind_Exception *exception_object);
85extern void _Unwind_Resume(_Unwind_Exception *exception_object);
86#endif
87extern void _Unwind_DeleteException(_Unwind_Exception *exception_object);
88
89typedef enum {
90 _UVRSC_CORE = 0, /* integer register */
91 _UVRSC_VFP = 1, /* vfp */
92 _UVRSC_WMMXD = 3, /* Intel WMMX data register */
93 _UVRSC_WMMXC = 4, /* Intel WMMX control register */
94 _UVRSC_PSEUDO = 5 /* Special purpose pseudo register */
95} _Unwind_VRS_RegClass;
96
97typedef enum {
98 _UVRSD_UINT32 = 0,
99 _UVRSD_VFPX = 1,
100 _UVRSD_UINT64 = 3,
101 _UVRSD_FLOAT = 4,
102 _UVRSD_DOUBLE = 5
103} _Unwind_VRS_DataRepresentation;
104
105typedef enum {
106 _UVRSR_OK = 0,
107 _UVRSR_NOT_IMPLEMENTED = 1,
108 _UVRSR_FAILED = 2
109} _Unwind_VRS_Result;
110
111extern void _Unwind_Complete(_Unwind_Exception* exception_object);
112
113extern _Unwind_VRS_Result
114_Unwind_VRS_Get(_Unwind_Context *context, _Unwind_VRS_RegClass regclass,
115 uint32_t regno, _Unwind_VRS_DataRepresentation representation,
116 void *valuep);
117
118extern _Unwind_VRS_Result
119_Unwind_VRS_Set(_Unwind_Context *context, _Unwind_VRS_RegClass regclass,
120 uint32_t regno, _Unwind_VRS_DataRepresentation representation,
121 void *valuep);
122
123extern _Unwind_VRS_Result
124_Unwind_VRS_Pop(_Unwind_Context *context, _Unwind_VRS_RegClass regclass,
125 uint32_t discriminator,
126 _Unwind_VRS_DataRepresentation representation);
127
128#if defined(_LIBUNWIND_UNWIND_LEVEL1_EXTERNAL_LINKAGE)
129#define _LIBUNWIND_EXPORT_UNWIND_LEVEL1 extern
130#else
131#define _LIBUNWIND_EXPORT_UNWIND_LEVEL1 static __inline__
132#endif
133
134// These are de facto helper functions for ARM, which delegate the function
135// calls to _Unwind_VRS_Get/Set(). These are not a part of ARM EHABI
136// specification, thus these function MUST be inlined. Please don't replace
137// these with the "extern" function declaration; otherwise, the program
138// including this <unwind.h> header won't be ABI compatible and will result in
139// link error when we are linking the program with libgcc.
140
141_LIBUNWIND_EXPORT_UNWIND_LEVEL1
142uintptr_t _Unwind_GetGR(struct _Unwind_Context *context, int index) {
143 uintptr_t value = 0;
144 _Unwind_VRS_Get(context, _UVRSC_CORE, (uint32_t)index, _UVRSD_UINT32, &value);
145 return value;
146}
147
148_LIBUNWIND_EXPORT_UNWIND_LEVEL1
149void _Unwind_SetGR(struct _Unwind_Context *context, int index,
150 uintptr_t value) {
151 _Unwind_VRS_Set(context, _UVRSC_CORE, (uint32_t)index, _UVRSD_UINT32, &value);
152}
153
154_LIBUNWIND_EXPORT_UNWIND_LEVEL1
155uintptr_t _Unwind_GetIP(struct _Unwind_Context *context) {
156 // remove the thumb-bit before returning
157 return _Unwind_GetGR(context, 15) & (~(uintptr_t)0x1);
158}
159
160_LIBUNWIND_EXPORT_UNWIND_LEVEL1
161void _Unwind_SetIP(struct _Unwind_Context *context, uintptr_t value) {
162 uintptr_t thumb_bit = _Unwind_GetGR(context, 15) & ((uintptr_t)0x1);
163 _Unwind_SetGR(context, 15, value | thumb_bit);
164}
165
166#ifdef __cplusplus
167}
168#endif
169
170#endif // __ARM_EHABI_UNWIND_H__