xref: /freebsd/contrib/llvm-project/clang/lib/Headers/unwind.h (revision ba3c1f5972d7b90feb6e6da47905ff2757e0fe57)
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_Control_Block;
69 #define _Unwind_Exception _Unwind_Control_Block /* Alias */
70 #else
71 struct _Unwind_Exception;
72 typedef struct _Unwind_Exception _Unwind_Exception;
73 #endif
74 typedef enum {
75   _URC_NO_REASON = 0,
76 #if defined(__arm__) && !defined(__USING_SJLJ_EXCEPTIONS__) && \
77     !defined(__ARM_DWARF_EH__) && !defined(__SEH__)
78   _URC_OK = 0, /* used by ARM EHABI */
79 #endif
80   _URC_FOREIGN_EXCEPTION_CAUGHT = 1,
81 
82   _URC_FATAL_PHASE2_ERROR = 2,
83   _URC_FATAL_PHASE1_ERROR = 3,
84   _URC_NORMAL_STOP = 4,
85 
86   _URC_END_OF_STACK = 5,
87   _URC_HANDLER_FOUND = 6,
88   _URC_INSTALL_CONTEXT = 7,
89   _URC_CONTINUE_UNWIND = 8,
90 #if defined(__arm__) && !defined(__USING_SJLJ_EXCEPTIONS__) && \
91     !defined(__ARM_DWARF_EH__) && !defined(__SEH__)
92   _URC_FAILURE = 9 /* used by ARM EHABI */
93 #endif
94 } _Unwind_Reason_Code;
95 
96 typedef enum {
97   _UA_SEARCH_PHASE = 1,
98   _UA_CLEANUP_PHASE = 2,
99 
100   _UA_HANDLER_FRAME = 4,
101   _UA_FORCE_UNWIND = 8,
102   _UA_END_OF_STACK = 16 /* gcc extension to C++ ABI */
103 } _Unwind_Action;
104 
105 typedef void (*_Unwind_Exception_Cleanup_Fn)(_Unwind_Reason_Code,
106                                              _Unwind_Exception *);
107 
108 #if defined(__arm__) && !(defined(__USING_SJLJ_EXCEPTIONS__) || \
109                           defined(__ARM_DWARF_EH__) || defined(__SEH__))
110 typedef struct _Unwind_Control_Block _Unwind_Control_Block;
111 typedef uint32_t _Unwind_EHT_Header;
112 
113 struct _Unwind_Control_Block {
114   uint64_t exception_class;
115   void (*exception_cleanup)(_Unwind_Reason_Code, _Unwind_Control_Block *);
116   /* unwinder cache (private fields for the unwinder's use) */
117   struct {
118     uint32_t reserved1; /* forced unwind stop function, 0 if not forced */
119     uint32_t reserved2; /* personality routine */
120     uint32_t reserved3; /* callsite */
121     uint32_t reserved4; /* forced unwind stop argument */
122     uint32_t reserved5;
123   } unwinder_cache;
124   /* propagation barrier cache (valid after phase 1) */
125   struct {
126     uint32_t sp;
127     uint32_t bitpattern[5];
128   } barrier_cache;
129   /* cleanup cache (preserved over cleanup) */
130   struct {
131     uint32_t bitpattern[4];
132   } cleanup_cache;
133   /* personality cache (for personality's benefit) */
134   struct {
135     uint32_t fnstart;         /* function start address */
136     _Unwind_EHT_Header *ehtp; /* pointer to EHT entry header word */
137     uint32_t additional;      /* additional data */
138     uint32_t reserved1;
139   } pr_cache;
140   long long int : 0; /* force alignment of next item to 8-byte boundary */
141 } __attribute__((__aligned__(8)));
142 #else
143 struct _Unwind_Exception {
144   _Unwind_Exception_Class exception_class;
145   _Unwind_Exception_Cleanup_Fn exception_cleanup;
146 #if !defined (__USING_SJLJ_EXCEPTIONS__) && defined (__SEH__)
147   _Unwind_Word private_[6];
148 #else
149   _Unwind_Word private_1;
150   _Unwind_Word private_2;
151 #endif
152   /* The Itanium ABI requires that _Unwind_Exception objects are "double-word
153    * aligned".  GCC has interpreted this to mean "use the maximum useful
154    * alignment for the target"; so do we. */
155 } __attribute__((__aligned__));
156 #endif
157 
158 typedef _Unwind_Reason_Code (*_Unwind_Stop_Fn)(int, _Unwind_Action,
159                                                _Unwind_Exception_Class,
160                                                _Unwind_Exception *,
161                                                struct _Unwind_Context *,
162                                                void *);
163 
164 typedef _Unwind_Reason_Code (*_Unwind_Personality_Fn)(int, _Unwind_Action,
165                                                       _Unwind_Exception_Class,
166                                                       _Unwind_Exception *,
167                                                       struct _Unwind_Context *);
168 typedef _Unwind_Personality_Fn __personality_routine;
169 
170 typedef _Unwind_Reason_Code (*_Unwind_Trace_Fn)(struct _Unwind_Context *,
171                                                 void *);
172 
173 #if defined(__arm__) && !(defined(__USING_SJLJ_EXCEPTIONS__) ||                \
174                           defined(__ARM_DWARF_EH__) || defined(__SEH__))
175 typedef enum {
176   _UVRSC_CORE = 0,        /* integer register */
177   _UVRSC_VFP = 1,         /* vfp */
178   _UVRSC_WMMXD = 3,       /* Intel WMMX data register */
179   _UVRSC_WMMXC = 4,       /* Intel WMMX control register */
180   _UVRSC_PSEUDO = 5       /* Special purpose pseudo register */
181 } _Unwind_VRS_RegClass;
182 
183 typedef enum {
184   _UVRSD_UINT32 = 0,
185   _UVRSD_VFPX = 1,
186   _UVRSD_UINT64 = 3,
187   _UVRSD_FLOAT = 4,
188   _UVRSD_DOUBLE = 5
189 } _Unwind_VRS_DataRepresentation;
190 
191 typedef enum {
192   _UVRSR_OK = 0,
193   _UVRSR_NOT_IMPLEMENTED = 1,
194   _UVRSR_FAILED = 2
195 } _Unwind_VRS_Result;
196 
197 typedef uint32_t _Unwind_State;
198 #define _US_VIRTUAL_UNWIND_FRAME  ((_Unwind_State)0)
199 #define _US_UNWIND_FRAME_STARTING ((_Unwind_State)1)
200 #define _US_UNWIND_FRAME_RESUME   ((_Unwind_State)2)
201 #define _US_ACTION_MASK           ((_Unwind_State)3)
202 #define _US_FORCE_UNWIND          ((_Unwind_State)8)
203 
204 _Unwind_VRS_Result _Unwind_VRS_Get(struct _Unwind_Context *__context,
205   _Unwind_VRS_RegClass __regclass,
206   uint32_t __regno,
207   _Unwind_VRS_DataRepresentation __representation,
208   void *__valuep);
209 
210 _Unwind_VRS_Result _Unwind_VRS_Set(struct _Unwind_Context *__context,
211   _Unwind_VRS_RegClass __regclass,
212   uint32_t __regno,
213   _Unwind_VRS_DataRepresentation __representation,
214   void *__valuep);
215 
216 static __inline__
217 _Unwind_Word _Unwind_GetGR(struct _Unwind_Context *__context, int __index) {
218   _Unwind_Word __value;
219   _Unwind_VRS_Get(__context, _UVRSC_CORE, __index, _UVRSD_UINT32, &__value);
220   return __value;
221 }
222 
223 static __inline__
224 void _Unwind_SetGR(struct _Unwind_Context *__context, int __index,
225                    _Unwind_Word __value) {
226   _Unwind_VRS_Set(__context, _UVRSC_CORE, __index, _UVRSD_UINT32, &__value);
227 }
228 
229 static __inline__
230 _Unwind_Word _Unwind_GetIP(struct _Unwind_Context *__context) {
231   _Unwind_Word __ip = _Unwind_GetGR(__context, 15);
232   return __ip & ~(_Unwind_Word)(0x1); /* Remove thumb mode bit. */
233 }
234 
235 static __inline__
236 void _Unwind_SetIP(struct _Unwind_Context *__context, _Unwind_Word __value) {
237   _Unwind_Word __thumb_mode_bit = _Unwind_GetGR(__context, 15) & 0x1;
238   _Unwind_SetGR(__context, 15, __value | __thumb_mode_bit);
239 }
240 #else
241 _Unwind_Word _Unwind_GetGR(struct _Unwind_Context *, int);
242 void _Unwind_SetGR(struct _Unwind_Context *, int, _Unwind_Word);
243 
244 _Unwind_Word _Unwind_GetIP(struct _Unwind_Context *);
245 void _Unwind_SetIP(struct _Unwind_Context *, _Unwind_Word);
246 #endif
247 
248 
249 _Unwind_Word _Unwind_GetIPInfo(struct _Unwind_Context *, int *);
250 
251 _Unwind_Word _Unwind_GetCFA(struct _Unwind_Context *);
252 
253 _Unwind_Word _Unwind_GetBSP(struct _Unwind_Context *);
254 
255 void *_Unwind_GetLanguageSpecificData(struct _Unwind_Context *);
256 
257 _Unwind_Ptr _Unwind_GetRegionStart(struct _Unwind_Context *);
258 
259 /* DWARF EH functions; currently not available on Darwin/ARM */
260 #if !defined(__APPLE__) || !defined(__arm__)
261 _Unwind_Reason_Code _Unwind_RaiseException(_Unwind_Exception *);
262 _Unwind_Reason_Code _Unwind_ForcedUnwind(_Unwind_Exception *, _Unwind_Stop_Fn,
263                                          void *);
264 void _Unwind_DeleteException(_Unwind_Exception *);
265 void _Unwind_Resume(_Unwind_Exception *);
266 _Unwind_Reason_Code _Unwind_Resume_or_Rethrow(_Unwind_Exception *);
267 
268 #endif
269 
270 _Unwind_Reason_Code _Unwind_Backtrace(_Unwind_Trace_Fn, void *);
271 
272 /* setjmp(3)/longjmp(3) stuff */
273 typedef struct SjLj_Function_Context *_Unwind_FunctionContext_t;
274 
275 void _Unwind_SjLj_Register(_Unwind_FunctionContext_t);
276 void _Unwind_SjLj_Unregister(_Unwind_FunctionContext_t);
277 _Unwind_Reason_Code _Unwind_SjLj_RaiseException(_Unwind_Exception *);
278 _Unwind_Reason_Code _Unwind_SjLj_ForcedUnwind(_Unwind_Exception *,
279                                               _Unwind_Stop_Fn, void *);
280 void _Unwind_SjLj_Resume(_Unwind_Exception *);
281 _Unwind_Reason_Code _Unwind_SjLj_Resume_or_Rethrow(_Unwind_Exception *);
282 
283 void *_Unwind_FindEnclosingFunction(void *);
284 
285 #ifdef __APPLE__
286 
287 _Unwind_Ptr _Unwind_GetDataRelBase(struct _Unwind_Context *)
288     __attribute__((__unavailable__));
289 _Unwind_Ptr _Unwind_GetTextRelBase(struct _Unwind_Context *)
290     __attribute__((__unavailable__));
291 
292 /* Darwin-specific functions */
293 void __register_frame(const void *);
294 void __deregister_frame(const void *);
295 
296 struct dwarf_eh_bases {
297   uintptr_t tbase;
298   uintptr_t dbase;
299   uintptr_t func;
300 };
301 void *_Unwind_Find_FDE(const void *, struct dwarf_eh_bases *);
302 
303 void __register_frame_info_bases(const void *, void *, void *, void *)
304   __attribute__((__unavailable__));
305 void __register_frame_info(const void *, void *) __attribute__((__unavailable__));
306 void __register_frame_info_table_bases(const void *, void*, void *, void *)
307   __attribute__((__unavailable__));
308 void __register_frame_info_table(const void *, void *)
309   __attribute__((__unavailable__));
310 void __register_frame_table(const void *) __attribute__((__unavailable__));
311 void __deregister_frame_info(const void *) __attribute__((__unavailable__));
312 void __deregister_frame_info_bases(const void *)__attribute__((__unavailable__));
313 
314 #else
315 
316 _Unwind_Ptr _Unwind_GetDataRelBase(struct _Unwind_Context *);
317 _Unwind_Ptr _Unwind_GetTextRelBase(struct _Unwind_Context *);
318 
319 #endif
320 
321 
322 #ifndef HIDE_EXPORTS
323 #pragma GCC visibility pop
324 #endif
325 
326 #ifdef __cplusplus
327 }
328 #endif
329 
330 #endif
331 
332 #endif /* __CLANG_UNWIND_H */
333