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
45 extern "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 
55 typedef uintptr_t _Unwind_Word __attribute__((__mode__(__unwind_word__)));
56 typedef intptr_t _Unwind_Sword __attribute__((__mode__(__unwind_word__)));
57 typedef uintptr_t _Unwind_Ptr;
58 typedef uintptr_t _Unwind_Internal_Ptr;
59 typedef uint64_t _Unwind_Exception_Class;
60 
61 typedef intptr_t _sleb128_t;
62 typedef uintptr_t _uleb128_t;
63 
64 struct _Unwind_Context;
65 #if defined(__arm__) && !(defined(__USING_SJLJ_EXCEPTIONS__) || \
66                           defined(__ARM_DWARF_EH__) || defined(__SEH__))
67 struct _Unwind_Control_Block;
68 typedef struct _Unwind_Control_Block _Unwind_Exception; /* Alias */
69 #else
70 struct _Unwind_Exception;
71 typedef struct _Unwind_Exception _Unwind_Exception;
72 #endif
73 typedef enum {
74   _URC_NO_REASON = 0,
75 #if defined(__arm__) && !defined(__USING_SJLJ_EXCEPTIONS__) && \
76     !defined(__ARM_DWARF_EH__) && !defined(__SEH__)
77   _URC_OK = 0, /* used by ARM EHABI */
78 #endif
79   _URC_FOREIGN_EXCEPTION_CAUGHT = 1,
80 
81   _URC_FATAL_PHASE2_ERROR = 2,
82   _URC_FATAL_PHASE1_ERROR = 3,
83   _URC_NORMAL_STOP = 4,
84 
85   _URC_END_OF_STACK = 5,
86   _URC_HANDLER_FOUND = 6,
87   _URC_INSTALL_CONTEXT = 7,
88   _URC_CONTINUE_UNWIND = 8,
89 #if defined(__arm__) && !defined(__USING_SJLJ_EXCEPTIONS__) && \
90     !defined(__ARM_DWARF_EH__) && !defined(__SEH__)
91   _URC_FAILURE = 9 /* used by ARM EHABI */
92 #endif
93 } _Unwind_Reason_Code;
94 
95 typedef enum {
96   _UA_SEARCH_PHASE = 1,
97   _UA_CLEANUP_PHASE = 2,
98 
99   _UA_HANDLER_FRAME = 4,
100   _UA_FORCE_UNWIND = 8,
101   _UA_END_OF_STACK = 16 /* gcc extension to C++ ABI */
102 } _Unwind_Action;
103 
104 typedef void (*_Unwind_Exception_Cleanup_Fn)(_Unwind_Reason_Code,
105                                              _Unwind_Exception *);
106 
107 #if defined(__arm__) && !(defined(__USING_SJLJ_EXCEPTIONS__) || \
108                           defined(__ARM_DWARF_EH__) || defined(__SEH__))
109 typedef struct _Unwind_Control_Block _Unwind_Control_Block;
110 typedef uint32_t _Unwind_EHT_Header;
111 
112 struct _Unwind_Control_Block {
113   uint64_t exception_class;
114   void (*exception_cleanup)(_Unwind_Reason_Code, _Unwind_Control_Block *);
115   /* unwinder cache (private fields for the unwinder's use) */
116   struct {
117     uint32_t reserved1; /* forced unwind stop function, 0 if not forced */
118     uint32_t reserved2; /* personality routine */
119     uint32_t reserved3; /* callsite */
120     uint32_t reserved4; /* forced unwind stop argument */
121     uint32_t reserved5;
122   } unwinder_cache;
123   /* propagation barrier cache (valid after phase 1) */
124   struct {
125     uint32_t sp;
126     uint32_t bitpattern[5];
127   } barrier_cache;
128   /* cleanup cache (preserved over cleanup) */
129   struct {
130     uint32_t bitpattern[4];
131   } cleanup_cache;
132   /* personality cache (for personality's benefit) */
133   struct {
134     uint32_t fnstart;         /* function start address */
135     _Unwind_EHT_Header *ehtp; /* pointer to EHT entry header word */
136     uint32_t additional;      /* additional data */
137     uint32_t reserved1;
138   } pr_cache;
139   long long int : 0; /* force alignment of next item to 8-byte boundary */
140 } __attribute__((__aligned__(8)));
141 #else
142 struct _Unwind_Exception {
143   _Unwind_Exception_Class exception_class;
144   _Unwind_Exception_Cleanup_Fn exception_cleanup;
145 #if !defined (__USING_SJLJ_EXCEPTIONS__) && defined (__SEH__)
146   _Unwind_Word private_[6];
147 #else
148   _Unwind_Word private_1;
149   _Unwind_Word private_2;
150 #endif
151   /* The Itanium ABI requires that _Unwind_Exception objects are "double-word
152    * aligned".  GCC has interpreted this to mean "use the maximum useful
153    * alignment for the target"; so do we. */
154 } __attribute__((__aligned__));
155 #endif
156 
157 typedef _Unwind_Reason_Code (*_Unwind_Stop_Fn)(int, _Unwind_Action,
158                                                _Unwind_Exception_Class,
159                                                _Unwind_Exception *,
160                                                struct _Unwind_Context *,
161                                                void *);
162 
163 typedef _Unwind_Reason_Code (*_Unwind_Personality_Fn)(int, _Unwind_Action,
164                                                       _Unwind_Exception_Class,
165                                                       _Unwind_Exception *,
166                                                       struct _Unwind_Context *);
167 typedef _Unwind_Personality_Fn __personality_routine;
168 
169 typedef _Unwind_Reason_Code (*_Unwind_Trace_Fn)(struct _Unwind_Context *,
170                                                 void *);
171 
172 #if defined(__arm__) && !(defined(__USING_SJLJ_EXCEPTIONS__) ||                \
173                           defined(__ARM_DWARF_EH__) || defined(__SEH__))
174 typedef enum {
175   _UVRSC_CORE = 0,        /* integer register */
176   _UVRSC_VFP = 1,         /* vfp */
177   _UVRSC_WMMXD = 3,       /* Intel WMMX data register */
178   _UVRSC_WMMXC = 4,       /* Intel WMMX control register */
179   _UVRSC_PSEUDO = 5       /* Special purpose pseudo register */
180 } _Unwind_VRS_RegClass;
181 
182 typedef enum {
183   _UVRSD_UINT32 = 0,
184   _UVRSD_VFPX = 1,
185   _UVRSD_UINT64 = 3,
186   _UVRSD_FLOAT = 4,
187   _UVRSD_DOUBLE = 5
188 } _Unwind_VRS_DataRepresentation;
189 
190 typedef enum {
191   _UVRSR_OK = 0,
192   _UVRSR_NOT_IMPLEMENTED = 1,
193   _UVRSR_FAILED = 2
194 } _Unwind_VRS_Result;
195 
196 typedef uint32_t _Unwind_State;
197 #define _US_VIRTUAL_UNWIND_FRAME  ((_Unwind_State)0)
198 #define _US_UNWIND_FRAME_STARTING ((_Unwind_State)1)
199 #define _US_UNWIND_FRAME_RESUME   ((_Unwind_State)2)
200 #define _US_ACTION_MASK           ((_Unwind_State)3)
201 #define _US_FORCE_UNWIND          ((_Unwind_State)8)
202 
203 _Unwind_VRS_Result _Unwind_VRS_Get(struct _Unwind_Context *__context,
204   _Unwind_VRS_RegClass __regclass,
205   uint32_t __regno,
206   _Unwind_VRS_DataRepresentation __representation,
207   void *__valuep);
208 
209 _Unwind_VRS_Result _Unwind_VRS_Set(struct _Unwind_Context *__context,
210   _Unwind_VRS_RegClass __regclass,
211   uint32_t __regno,
212   _Unwind_VRS_DataRepresentation __representation,
213   void *__valuep);
214 
215 static __inline__
216 _Unwind_Word _Unwind_GetGR(struct _Unwind_Context *__context, int __index) {
217   _Unwind_Word __value;
218   _Unwind_VRS_Get(__context, _UVRSC_CORE, __index, _UVRSD_UINT32, &__value);
219   return __value;
220 }
221 
222 static __inline__
223 void _Unwind_SetGR(struct _Unwind_Context *__context, int __index,
224                    _Unwind_Word __value) {
225   _Unwind_VRS_Set(__context, _UVRSC_CORE, __index, _UVRSD_UINT32, &__value);
226 }
227 
228 static __inline__
229 _Unwind_Word _Unwind_GetIP(struct _Unwind_Context *__context) {
230   _Unwind_Word __ip = _Unwind_GetGR(__context, 15);
231   return __ip & ~(_Unwind_Word)(0x1); /* Remove thumb mode bit. */
232 }
233 
234 static __inline__
235 void _Unwind_SetIP(struct _Unwind_Context *__context, _Unwind_Word __value) {
236   _Unwind_Word __thumb_mode_bit = _Unwind_GetGR(__context, 15) & 0x1;
237   _Unwind_SetGR(__context, 15, __value | __thumb_mode_bit);
238 }
239 #else
240 _Unwind_Word _Unwind_GetGR(struct _Unwind_Context *, int);
241 void _Unwind_SetGR(struct _Unwind_Context *, int, _Unwind_Word);
242 
243 _Unwind_Word _Unwind_GetIP(struct _Unwind_Context *);
244 void _Unwind_SetIP(struct _Unwind_Context *, _Unwind_Word);
245 #endif
246 
247 
248 _Unwind_Word _Unwind_GetIPInfo(struct _Unwind_Context *, int *);
249 
250 _Unwind_Word _Unwind_GetCFA(struct _Unwind_Context *);
251 
252 _Unwind_Word _Unwind_GetBSP(struct _Unwind_Context *);
253 
254 void *_Unwind_GetLanguageSpecificData(struct _Unwind_Context *);
255 
256 _Unwind_Ptr _Unwind_GetRegionStart(struct _Unwind_Context *);
257 
258 /* DWARF EH functions; currently not available on Darwin/ARM */
259 #if !defined(__APPLE__) || !defined(__arm__)
260 _Unwind_Reason_Code _Unwind_RaiseException(_Unwind_Exception *);
261 _Unwind_Reason_Code _Unwind_ForcedUnwind(_Unwind_Exception *, _Unwind_Stop_Fn,
262                                          void *);
263 void _Unwind_DeleteException(_Unwind_Exception *);
264 void _Unwind_Resume(_Unwind_Exception *);
265 _Unwind_Reason_Code _Unwind_Resume_or_Rethrow(_Unwind_Exception *);
266 
267 #endif
268 
269 _Unwind_Reason_Code _Unwind_Backtrace(_Unwind_Trace_Fn, void *);
270 
271 /* setjmp(3)/longjmp(3) stuff */
272 typedef struct SjLj_Function_Context *_Unwind_FunctionContext_t;
273 
274 void _Unwind_SjLj_Register(_Unwind_FunctionContext_t);
275 void _Unwind_SjLj_Unregister(_Unwind_FunctionContext_t);
276 _Unwind_Reason_Code _Unwind_SjLj_RaiseException(_Unwind_Exception *);
277 _Unwind_Reason_Code _Unwind_SjLj_ForcedUnwind(_Unwind_Exception *,
278                                               _Unwind_Stop_Fn, void *);
279 void _Unwind_SjLj_Resume(_Unwind_Exception *);
280 _Unwind_Reason_Code _Unwind_SjLj_Resume_or_Rethrow(_Unwind_Exception *);
281 
282 void *_Unwind_FindEnclosingFunction(void *);
283 
284 #ifdef __APPLE__
285 
286 _Unwind_Ptr _Unwind_GetDataRelBase(struct _Unwind_Context *)
287     __attribute__((__unavailable__));
288 _Unwind_Ptr _Unwind_GetTextRelBase(struct _Unwind_Context *)
289     __attribute__((__unavailable__));
290 
291 /* Darwin-specific functions */
292 void __register_frame(const void *);
293 void __deregister_frame(const void *);
294 
295 struct dwarf_eh_bases {
296   uintptr_t tbase;
297   uintptr_t dbase;
298   uintptr_t func;
299 };
300 void *_Unwind_Find_FDE(const void *, struct dwarf_eh_bases *);
301 
302 void __register_frame_info_bases(const void *, void *, void *, void *)
303   __attribute__((__unavailable__));
304 void __register_frame_info(const void *, void *) __attribute__((__unavailable__));
305 void __register_frame_info_table_bases(const void *, void*, void *, void *)
306   __attribute__((__unavailable__));
307 void __register_frame_info_table(const void *, void *)
308   __attribute__((__unavailable__));
309 void __register_frame_table(const void *) __attribute__((__unavailable__));
310 void __deregister_frame_info(const void *) __attribute__((__unavailable__));
311 void __deregister_frame_info_bases(const void *)__attribute__((__unavailable__));
312 
313 #else
314 
315 _Unwind_Ptr _Unwind_GetDataRelBase(struct _Unwind_Context *);
316 _Unwind_Ptr _Unwind_GetTextRelBase(struct _Unwind_Context *);
317 
318 #endif
319 
320 
321 #ifndef HIDE_EXPORTS
322 #pragma GCC visibility pop
323 #endif
324 
325 #ifdef __cplusplus
326 }
327 #endif
328 
329 #endif
330 
331 #endif /* __CLANG_UNWIND_H */
332