xref: /freebsd/contrib/llvm-project/clang/lib/Headers/unwind.h (revision dd41de95a84d979615a2ef11df6850622bf6184e)
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__) || defined(__ARM_DWARF_EH__))
66 struct _Unwind_Control_Block;
67 typedef struct _Unwind_Control_Block _Unwind_Exception; /* Alias */
68 #else
69 struct _Unwind_Exception;
70 typedef struct _Unwind_Exception _Unwind_Exception;
71 #endif
72 typedef 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 
94 typedef 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 
103 typedef void (*_Unwind_Exception_Cleanup_Fn)(_Unwind_Reason_Code,
104                                              _Unwind_Exception *);
105 
106 #if defined(__arm__) && !(defined(__USING_SJLJ_EXCEPTIONS__) || defined(__ARM_DWARF_EH__))
107 typedef struct _Unwind_Control_Block _Unwind_Control_Block;
108 typedef uint32_t _Unwind_EHT_Header;
109 
110 struct _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
140 struct _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 
155 typedef _Unwind_Reason_Code (*_Unwind_Stop_Fn)(int, _Unwind_Action,
156                                                _Unwind_Exception_Class,
157                                                _Unwind_Exception *,
158                                                struct _Unwind_Context *,
159                                                void *);
160 
161 typedef _Unwind_Reason_Code (*_Unwind_Personality_Fn)(int, _Unwind_Action,
162                                                       _Unwind_Exception_Class,
163                                                       _Unwind_Exception *,
164                                                       struct _Unwind_Context *);
165 typedef _Unwind_Personality_Fn __personality_routine;
166 
167 typedef _Unwind_Reason_Code (*_Unwind_Trace_Fn)(struct _Unwind_Context *,
168                                                 void *);
169 
170 #if defined(__arm__) && !(defined(__USING_SJLJ_EXCEPTIONS__) || defined(__ARM_DWARF_EH__))
171 typedef 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 
178 typedef 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 
186 typedef enum {
187   _UVRSR_OK = 0,
188   _UVRSR_NOT_IMPLEMENTED = 1,
189   _UVRSR_FAILED = 2
190 } _Unwind_VRS_Result;
191 
192 typedef 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 
211 static __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 
218 static __inline__
219 void _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 
224 static __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 
230 static __inline__
231 void _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);
237 void _Unwind_SetGR(struct _Unwind_Context *, int, _Unwind_Word);
238 
239 _Unwind_Word _Unwind_GetIP(struct _Unwind_Context *);
240 void _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 
250 void *_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 *);
259 void _Unwind_DeleteException(_Unwind_Exception *);
260 void _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 */
268 typedef struct SjLj_Function_Context *_Unwind_FunctionContext_t;
269 
270 void _Unwind_SjLj_Register(_Unwind_FunctionContext_t);
271 void _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 *);
275 void _Unwind_SjLj_Resume(_Unwind_Exception *);
276 _Unwind_Reason_Code _Unwind_SjLj_Resume_or_Rethrow(_Unwind_Exception *);
277 
278 void *_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 */
288 void __register_frame(const void *);
289 void __deregister_frame(const void *);
290 
291 struct dwarf_eh_bases {
292   uintptr_t tbase;
293   uintptr_t dbase;
294   uintptr_t func;
295 };
296 void *_Unwind_Find_FDE(const void *, struct dwarf_eh_bases *);
297 
298 void __register_frame_info_bases(const void *, void *, void *, void *)
299   __attribute__((__unavailable__));
300 void __register_frame_info(const void *, void *) __attribute__((__unavailable__));
301 void __register_frame_info_table_bases(const void *, void*, void *, void *)
302   __attribute__((__unavailable__));
303 void __register_frame_info_table(const void *, void *)
304   __attribute__((__unavailable__));
305 void __register_frame_table(const void *) __attribute__((__unavailable__));
306 void __deregister_frame_info(const void *) __attribute__((__unavailable__));
307 void __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