1/*===---- unwind.h - Stack unwinding ----------------------------------------===
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
10/* See "Data Definitions for libgcc_s" in the Linux Standard Base.*/
11
12#ifndef __CLANG_UNWIND_H
13#define __CLANG_UNWIND_H
14
15#if defined(__APPLE__) && __has_include_next(<unwind.h>)
16/* Darwin (from 11.x on) provide an unwind.h. If that's available,
17 * use it. libunwind wraps some of its definitions in #ifdef _GNU_SOURCE,
18 * so define that around the include.*/
19# ifndef _GNU_SOURCE
20#  define _SHOULD_UNDEFINE_GNU_SOURCE
21#  define _GNU_SOURCE
22# endif
23// libunwind's unwind.h reflects the current visibility.  However, Mozilla
24// builds with -fvisibility=hidden and relies on gcc's unwind.h to reset the
25// visibility to default and export its contents.  gcc also allows users to
26// override its override by #defining HIDE_EXPORTS (but note, this only obeys
27// the user's -fvisibility setting; it doesn't hide any exports on its own).  We
28// imitate gcc's header here:
29# ifdef HIDE_EXPORTS
30#  include_next <unwind.h>
31# else
32#  pragma GCC visibility push(default)
33#  include_next <unwind.h>
34#  pragma GCC visibility pop
35# endif
36# ifdef _SHOULD_UNDEFINE_GNU_SOURCE
37#  undef _GNU_SOURCE
38#  undef _SHOULD_UNDEFINE_GNU_SOURCE
39# endif
40#else
41
42#include <stdint.h>
43
44#ifdef __cplusplus
45extern "C" {
46#endif
47
48/* It is a bit strange for a header to play with the visibility of the
49   symbols it declares, but this matches gcc's behavior and some programs
50   depend on it */
51#ifndef HIDE_EXPORTS
52#pragma GCC visibility push(default)
53#endif
54
55typedef uintptr_t _Unwind_Word __attribute__((__mode__(__unwind_word__)));
56typedef intptr_t _Unwind_Sword __attribute__((__mode__(__unwind_word__)));
57typedef uintptr_t _Unwind_Ptr;
58typedef uintptr_t _Unwind_Internal_Ptr;
59typedef uint64_t _Unwind_Exception_Class;
60
61typedef intptr_t _sleb128_t;
62typedef uintptr_t _uleb128_t;
63
64struct _Unwind_Context;
65#if defined(__arm__) && !(defined(__USING_SJLJ_EXCEPTIONS__) || defined(__ARM_DWARF_EH__))
66struct _Unwind_Control_Block;
67typedef struct _Unwind_Control_Block _Unwind_Exception; /* Alias */
68#else
69struct _Unwind_Exception;
70typedef struct _Unwind_Exception _Unwind_Exception;
71#endif
72typedef enum {
73  _URC_NO_REASON = 0,
74#if defined(__arm__) && !defined(__USING_SJLJ_EXCEPTIONS__) && \
75    !defined(__ARM_DWARF_EH__)
76  _URC_OK = 0, /* used by ARM EHABI */
77#endif
78  _URC_FOREIGN_EXCEPTION_CAUGHT = 1,
79
80  _URC_FATAL_PHASE2_ERROR = 2,
81  _URC_FATAL_PHASE1_ERROR = 3,
82  _URC_NORMAL_STOP = 4,
83
84  _URC_END_OF_STACK = 5,
85  _URC_HANDLER_FOUND = 6,
86  _URC_INSTALL_CONTEXT = 7,
87  _URC_CONTINUE_UNWIND = 8,
88#if defined(__arm__) && !defined(__USING_SJLJ_EXCEPTIONS__) && \
89    !defined(__ARM_DWARF_EH__)
90  _URC_FAILURE = 9 /* used by ARM EHABI */
91#endif
92} _Unwind_Reason_Code;
93
94typedef enum {
95  _UA_SEARCH_PHASE = 1,
96  _UA_CLEANUP_PHASE = 2,
97
98  _UA_HANDLER_FRAME = 4,
99  _UA_FORCE_UNWIND = 8,
100  _UA_END_OF_STACK = 16 /* gcc extension to C++ ABI */
101} _Unwind_Action;
102
103typedef void (*_Unwind_Exception_Cleanup_Fn)(_Unwind_Reason_Code,
104                                             _Unwind_Exception *);
105
106#if defined(__arm__) && !(defined(__USING_SJLJ_EXCEPTIONS__) || defined(__ARM_DWARF_EH__))
107typedef struct _Unwind_Control_Block _Unwind_Control_Block;
108typedef uint32_t _Unwind_EHT_Header;
109
110struct _Unwind_Control_Block {
111  uint64_t exception_class;
112  void (*exception_cleanup)(_Unwind_Reason_Code, _Unwind_Control_Block *);
113  /* unwinder cache (private fields for the unwinder's use) */
114  struct {
115    uint32_t reserved1; /* forced unwind stop function, 0 if not forced */
116    uint32_t reserved2; /* personality routine */
117    uint32_t reserved3; /* callsite */
118    uint32_t reserved4; /* forced unwind stop argument */
119    uint32_t reserved5;
120  } unwinder_cache;
121  /* propagation barrier cache (valid after phase 1) */
122  struct {
123    uint32_t sp;
124    uint32_t bitpattern[5];
125  } barrier_cache;
126  /* cleanup cache (preserved over cleanup) */
127  struct {
128    uint32_t bitpattern[4];
129  } cleanup_cache;
130  /* personality cache (for personality's benefit) */
131  struct {
132    uint32_t fnstart;         /* function start address */
133    _Unwind_EHT_Header *ehtp; /* pointer to EHT entry header word */
134    uint32_t additional;      /* additional data */
135    uint32_t reserved1;
136  } pr_cache;
137  long long int : 0; /* force alignment of next item to 8-byte boundary */
138} __attribute__((__aligned__(8)));
139#else
140struct _Unwind_Exception {
141  _Unwind_Exception_Class exception_class;
142  _Unwind_Exception_Cleanup_Fn exception_cleanup;
143#if !defined (__USING_SJLJ_EXCEPTIONS__) && defined (__SEH__)
144  _Unwind_Word private_[6];
145#else
146  _Unwind_Word private_1;
147  _Unwind_Word private_2;
148#endif
149  /* The Itanium ABI requires that _Unwind_Exception objects are "double-word
150   * aligned".  GCC has interpreted this to mean "use the maximum useful
151   * alignment for the target"; so do we. */
152} __attribute__((__aligned__));
153#endif
154
155typedef _Unwind_Reason_Code (*_Unwind_Stop_Fn)(int, _Unwind_Action,
156                                               _Unwind_Exception_Class,
157                                               _Unwind_Exception *,
158                                               struct _Unwind_Context *,
159                                               void *);
160
161typedef _Unwind_Reason_Code (*_Unwind_Personality_Fn)(int, _Unwind_Action,
162                                                      _Unwind_Exception_Class,
163                                                      _Unwind_Exception *,
164                                                      struct _Unwind_Context *);
165typedef _Unwind_Personality_Fn __personality_routine;
166
167typedef _Unwind_Reason_Code (*_Unwind_Trace_Fn)(struct _Unwind_Context *,
168                                                void *);
169
170#if defined(__arm__) && !(defined(__USING_SJLJ_EXCEPTIONS__) || defined(__ARM_DWARF_EH__))
171typedef enum {
172  _UVRSC_CORE = 0,        /* integer register */
173  _UVRSC_VFP = 1,         /* vfp */
174  _UVRSC_WMMXD = 3,       /* Intel WMMX data register */
175  _UVRSC_WMMXC = 4        /* Intel WMMX control register */
176} _Unwind_VRS_RegClass;
177
178typedef enum {
179  _UVRSD_UINT32 = 0,
180  _UVRSD_VFPX = 1,
181  _UVRSD_UINT64 = 3,
182  _UVRSD_FLOAT = 4,
183  _UVRSD_DOUBLE = 5
184} _Unwind_VRS_DataRepresentation;
185
186typedef enum {
187  _UVRSR_OK = 0,
188  _UVRSR_NOT_IMPLEMENTED = 1,
189  _UVRSR_FAILED = 2
190} _Unwind_VRS_Result;
191
192typedef uint32_t _Unwind_State;
193#define _US_VIRTUAL_UNWIND_FRAME  ((_Unwind_State)0)
194#define _US_UNWIND_FRAME_STARTING ((_Unwind_State)1)
195#define _US_UNWIND_FRAME_RESUME   ((_Unwind_State)2)
196#define _US_ACTION_MASK           ((_Unwind_State)3)
197#define _US_FORCE_UNWIND          ((_Unwind_State)8)
198
199_Unwind_VRS_Result _Unwind_VRS_Get(struct _Unwind_Context *__context,
200  _Unwind_VRS_RegClass __regclass,
201  uint32_t __regno,
202  _Unwind_VRS_DataRepresentation __representation,
203  void *__valuep);
204
205_Unwind_VRS_Result _Unwind_VRS_Set(struct _Unwind_Context *__context,
206  _Unwind_VRS_RegClass __regclass,
207  uint32_t __regno,
208  _Unwind_VRS_DataRepresentation __representation,
209  void *__valuep);
210
211static __inline__
212_Unwind_Word _Unwind_GetGR(struct _Unwind_Context *__context, int __index) {
213  _Unwind_Word __value;
214  _Unwind_VRS_Get(__context, _UVRSC_CORE, __index, _UVRSD_UINT32, &__value);
215  return __value;
216}
217
218static __inline__
219void _Unwind_SetGR(struct _Unwind_Context *__context, int __index,
220                   _Unwind_Word __value) {
221  _Unwind_VRS_Set(__context, _UVRSC_CORE, __index, _UVRSD_UINT32, &__value);
222}
223
224static __inline__
225_Unwind_Word _Unwind_GetIP(struct _Unwind_Context *__context) {
226  _Unwind_Word __ip = _Unwind_GetGR(__context, 15);
227  return __ip & ~(_Unwind_Word)(0x1); /* Remove thumb mode bit. */
228}
229
230static __inline__
231void _Unwind_SetIP(struct _Unwind_Context *__context, _Unwind_Word __value) {
232  _Unwind_Word __thumb_mode_bit = _Unwind_GetGR(__context, 15) & 0x1;
233  _Unwind_SetGR(__context, 15, __value | __thumb_mode_bit);
234}
235#else
236_Unwind_Word _Unwind_GetGR(struct _Unwind_Context *, int);
237void _Unwind_SetGR(struct _Unwind_Context *, int, _Unwind_Word);
238
239_Unwind_Word _Unwind_GetIP(struct _Unwind_Context *);
240void _Unwind_SetIP(struct _Unwind_Context *, _Unwind_Word);
241#endif
242
243
244_Unwind_Word _Unwind_GetIPInfo(struct _Unwind_Context *, int *);
245
246_Unwind_Word _Unwind_GetCFA(struct _Unwind_Context *);
247
248_Unwind_Word _Unwind_GetBSP(struct _Unwind_Context *);
249
250void *_Unwind_GetLanguageSpecificData(struct _Unwind_Context *);
251
252_Unwind_Ptr _Unwind_GetRegionStart(struct _Unwind_Context *);
253
254/* DWARF EH functions; currently not available on Darwin/ARM */
255#if !defined(__APPLE__) || !defined(__arm__)
256_Unwind_Reason_Code _Unwind_RaiseException(_Unwind_Exception *);
257_Unwind_Reason_Code _Unwind_ForcedUnwind(_Unwind_Exception *, _Unwind_Stop_Fn,
258                                         void *);
259void _Unwind_DeleteException(_Unwind_Exception *);
260void _Unwind_Resume(_Unwind_Exception *);
261_Unwind_Reason_Code _Unwind_Resume_or_Rethrow(_Unwind_Exception *);
262
263#endif
264
265_Unwind_Reason_Code _Unwind_Backtrace(_Unwind_Trace_Fn, void *);
266
267/* setjmp(3)/longjmp(3) stuff */
268typedef struct SjLj_Function_Context *_Unwind_FunctionContext_t;
269
270void _Unwind_SjLj_Register(_Unwind_FunctionContext_t);
271void _Unwind_SjLj_Unregister(_Unwind_FunctionContext_t);
272_Unwind_Reason_Code _Unwind_SjLj_RaiseException(_Unwind_Exception *);
273_Unwind_Reason_Code _Unwind_SjLj_ForcedUnwind(_Unwind_Exception *,
274                                              _Unwind_Stop_Fn, void *);
275void _Unwind_SjLj_Resume(_Unwind_Exception *);
276_Unwind_Reason_Code _Unwind_SjLj_Resume_or_Rethrow(_Unwind_Exception *);
277
278void *_Unwind_FindEnclosingFunction(void *);
279
280#ifdef __APPLE__
281
282_Unwind_Ptr _Unwind_GetDataRelBase(struct _Unwind_Context *)
283    __attribute__((__unavailable__));
284_Unwind_Ptr _Unwind_GetTextRelBase(struct _Unwind_Context *)
285    __attribute__((__unavailable__));
286
287/* Darwin-specific functions */
288void __register_frame(const void *);
289void __deregister_frame(const void *);
290
291struct dwarf_eh_bases {
292  uintptr_t tbase;
293  uintptr_t dbase;
294  uintptr_t func;
295};
296void *_Unwind_Find_FDE(const void *, struct dwarf_eh_bases *);
297
298void __register_frame_info_bases(const void *, void *, void *, void *)
299  __attribute__((__unavailable__));
300void __register_frame_info(const void *, void *) __attribute__((__unavailable__));
301void __register_frame_info_table_bases(const void *, void*, void *, void *)
302  __attribute__((__unavailable__));
303void __register_frame_info_table(const void *, void *)
304  __attribute__((__unavailable__));
305void __register_frame_table(const void *) __attribute__((__unavailable__));
306void __deregister_frame_info(const void *) __attribute__((__unavailable__));
307void __deregister_frame_info_bases(const void *)__attribute__((__unavailable__));
308
309#else
310
311_Unwind_Ptr _Unwind_GetDataRelBase(struct _Unwind_Context *);
312_Unwind_Ptr _Unwind_GetTextRelBase(struct _Unwind_Context *);
313
314#endif
315
316
317#ifndef HIDE_EXPORTS
318#pragma GCC visibility pop
319#endif
320
321#ifdef __cplusplus
322}
323#endif
324
325#endif
326
327#endif /* __CLANG_UNWIND_H */
328