1 //===------------------------------- unwind.h -----------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //
9 // C++ ABI Level 1 ABI documented at:
10 // http://mentorembedded.github.io/cxx-abi/abi-eh.html
11 //
12 //===----------------------------------------------------------------------===//
13
14 #ifndef __UNWIND_H__
15 #define __UNWIND_H__
16
17 #include <__libunwind_config.h>
18
19 #include <stdint.h>
20 #include <stddef.h>
21
22 #if defined(__APPLE__)
23 #define LIBUNWIND_UNAVAIL __attribute__ (( unavailable ))
24 #else
25 #define LIBUNWIND_UNAVAIL
26 #endif
27
28 typedef enum {
29 _URC_NO_REASON = 0,
30 _URC_OK = 0,
31 _URC_FOREIGN_EXCEPTION_CAUGHT = 1,
32 _URC_FATAL_PHASE2_ERROR = 2,
33 _URC_FATAL_PHASE1_ERROR = 3,
34 _URC_NORMAL_STOP = 4,
35 _URC_END_OF_STACK = 5,
36 _URC_HANDLER_FOUND = 6,
37 _URC_INSTALL_CONTEXT = 7,
38 _URC_CONTINUE_UNWIND = 8,
39 #if defined(_LIBUNWIND_ARM_EHABI)
40 _URC_FAILURE = 9
41 #endif
42 } _Unwind_Reason_Code;
43
44 typedef enum {
45 _UA_SEARCH_PHASE = 1,
46 _UA_CLEANUP_PHASE = 2,
47 _UA_HANDLER_FRAME = 4,
48 _UA_FORCE_UNWIND = 8,
49 _UA_END_OF_STACK = 16 // gcc extension to C++ ABI
50 } _Unwind_Action;
51
52 typedef struct _Unwind_Context _Unwind_Context; // opaque
53
54 #if defined(_LIBUNWIND_ARM_EHABI)
55 typedef uint32_t _Unwind_State;
56
57 static const _Unwind_State _US_VIRTUAL_UNWIND_FRAME = 0;
58 static const _Unwind_State _US_UNWIND_FRAME_STARTING = 1;
59 static const _Unwind_State _US_UNWIND_FRAME_RESUME = 2;
60 static const _Unwind_State _US_ACTION_MASK = 3;
61 /* Undocumented flag for force unwinding. */
62 static const _Unwind_State _US_FORCE_UNWIND = 8;
63
64 typedef uint32_t _Unwind_EHT_Header;
65
66 struct _Unwind_Control_Block;
67 typedef struct _Unwind_Control_Block _Unwind_Control_Block;
68 typedef struct _Unwind_Control_Block _Unwind_Exception; /* Alias */
69
70 struct _Unwind_Control_Block {
71 uint64_t exception_class;
72 void (*exception_cleanup)(_Unwind_Reason_Code, _Unwind_Control_Block*);
73
74 /* Unwinder cache, private fields for the unwinder's use */
75 struct {
76 uint32_t reserved1; /* init reserved1 to 0, then don't touch */
77 uint32_t reserved2;
78 uint32_t reserved3;
79 uint32_t reserved4;
80 uint32_t reserved5;
81 } unwinder_cache;
82
83 /* Propagation barrier cache (valid after phase 1): */
84 struct {
85 uint32_t sp;
86 uint32_t bitpattern[5];
87 } barrier_cache;
88
89 /* Cleanup cache (preserved over cleanup): */
90 struct {
91 uint32_t bitpattern[4];
92 } cleanup_cache;
93
94 /* Pr cache (for pr's benefit): */
95 struct {
96 uint32_t fnstart; /* function start address */
97 _Unwind_EHT_Header* ehtp; /* pointer to EHT entry header word */
98 uint32_t additional;
99 uint32_t reserved1;
100 } pr_cache;
101
102 long long int :0; /* Enforce the 8-byte alignment */
103 };
104
105 typedef _Unwind_Reason_Code (*_Unwind_Stop_Fn)
106 (_Unwind_State state,
107 _Unwind_Exception* exceptionObject,
108 struct _Unwind_Context* context);
109
110 typedef _Unwind_Reason_Code (*__personality_routine)
111 (_Unwind_State state,
112 _Unwind_Exception* exceptionObject,
113 struct _Unwind_Context* context);
114 #else
115 struct _Unwind_Context; // opaque
116 struct _Unwind_Exception; // forward declaration
117 typedef struct _Unwind_Exception _Unwind_Exception;
118
119 struct _Unwind_Exception {
120 uint64_t exception_class;
121 void (*exception_cleanup)(_Unwind_Reason_Code reason,
122 _Unwind_Exception *exc);
123 uintptr_t private_1; // non-zero means forced unwind
124 uintptr_t private_2; // holds sp that phase1 found for phase2 to use
125 #ifndef __LP64__
126 // The implementation of _Unwind_Exception uses an attribute mode on the
127 // above fields which has the side effect of causing this whole struct to
128 // round up to 32 bytes in size. To be more explicit, we add pad fields
129 // added for binary compatibility.
130 uint32_t reserved[3];
131 #endif
132 // The Itanium ABI requires that _Unwind_Exception objects are "double-word
133 // aligned". GCC has interpreted this to mean "use the maximum useful
134 // alignment for the target"; so do we.
135 } __attribute__((__aligned__));
136
137 typedef _Unwind_Reason_Code (*_Unwind_Stop_Fn)
138 (int version,
139 _Unwind_Action actions,
140 uint64_t exceptionClass,
141 _Unwind_Exception* exceptionObject,
142 struct _Unwind_Context* context,
143 void* stop_parameter );
144
145 typedef _Unwind_Reason_Code (*__personality_routine)
146 (int version,
147 _Unwind_Action actions,
148 uint64_t exceptionClass,
149 _Unwind_Exception* exceptionObject,
150 struct _Unwind_Context* context);
151 #endif
152
153 #ifdef __cplusplus
154 extern "C" {
155 #endif
156
157 //
158 // The following are the base functions documented by the C++ ABI
159 //
160 #ifdef __USING_SJLJ_EXCEPTIONS__
161 extern _Unwind_Reason_Code
162 _Unwind_SjLj_RaiseException(_Unwind_Exception *exception_object);
163 extern void _Unwind_SjLj_Resume(_Unwind_Exception *exception_object);
164 #else
165 extern _Unwind_Reason_Code
166 _Unwind_RaiseException(_Unwind_Exception *exception_object);
167 extern void _Unwind_Resume(_Unwind_Exception *exception_object);
168 #endif
169 extern void _Unwind_DeleteException(_Unwind_Exception *exception_object);
170
171 #if defined(_LIBUNWIND_ARM_EHABI)
172 typedef enum {
173 _UVRSC_CORE = 0, /* integer register */
174 _UVRSC_VFP = 1, /* vfp */
175 _UVRSC_WMMXD = 3, /* Intel WMMX data register */
176 _UVRSC_WMMXC = 4 /* Intel WMMX control register */
177 } _Unwind_VRS_RegClass;
178
179 typedef enum {
180 _UVRSD_UINT32 = 0,
181 _UVRSD_VFPX = 1,
182 _UVRSD_UINT64 = 3,
183 _UVRSD_FLOAT = 4,
184 _UVRSD_DOUBLE = 5
185 } _Unwind_VRS_DataRepresentation;
186
187 typedef enum {
188 _UVRSR_OK = 0,
189 _UVRSR_NOT_IMPLEMENTED = 1,
190 _UVRSR_FAILED = 2
191 } _Unwind_VRS_Result;
192
193 extern void _Unwind_Complete(_Unwind_Exception* exception_object);
194
195 extern _Unwind_VRS_Result
196 _Unwind_VRS_Get(_Unwind_Context *context, _Unwind_VRS_RegClass regclass,
197 uint32_t regno, _Unwind_VRS_DataRepresentation representation,
198 void *valuep);
199
200 extern _Unwind_VRS_Result
201 _Unwind_VRS_Set(_Unwind_Context *context, _Unwind_VRS_RegClass regclass,
202 uint32_t regno, _Unwind_VRS_DataRepresentation representation,
203 void *valuep);
204
205 extern _Unwind_VRS_Result
206 _Unwind_VRS_Pop(_Unwind_Context *context, _Unwind_VRS_RegClass regclass,
207 uint32_t discriminator,
208 _Unwind_VRS_DataRepresentation representation);
209 #endif
210
211 #if !defined(_LIBUNWIND_ARM_EHABI)
212
213 extern uintptr_t _Unwind_GetGR(struct _Unwind_Context *context, int index);
214 extern void _Unwind_SetGR(struct _Unwind_Context *context, int index,
215 uintptr_t new_value);
216 extern uintptr_t _Unwind_GetIP(struct _Unwind_Context *context);
217 extern void _Unwind_SetIP(struct _Unwind_Context *, uintptr_t new_value);
218
219 #else // defined(_LIBUNWIND_ARM_EHABI)
220
221 #if defined(_LIBUNWIND_UNWIND_LEVEL1_EXTERNAL_LINKAGE)
222 #define _LIBUNWIND_EXPORT_UNWIND_LEVEL1 extern
223 #else
224 #define _LIBUNWIND_EXPORT_UNWIND_LEVEL1 static __inline__
225 #endif
226
227 // These are de facto helper functions for ARM, which delegate the function
228 // calls to _Unwind_VRS_Get/Set(). These are not a part of ARM EHABI
229 // specification, thus these function MUST be inlined. Please don't replace
230 // these with the "extern" function declaration; otherwise, the program
231 // including this <unwind.h> header won't be ABI compatible and will result in
232 // link error when we are linking the program with libgcc.
233
234 _LIBUNWIND_EXPORT_UNWIND_LEVEL1
_Unwind_GetGR(struct _Unwind_Context * context,int index)235 uintptr_t _Unwind_GetGR(struct _Unwind_Context *context, int index) {
236 uintptr_t value = 0;
237 _Unwind_VRS_Get(context, _UVRSC_CORE, (uint32_t)index, _UVRSD_UINT32, &value);
238 return value;
239 }
240
241 _LIBUNWIND_EXPORT_UNWIND_LEVEL1
_Unwind_SetGR(struct _Unwind_Context * context,int index,uintptr_t value)242 void _Unwind_SetGR(struct _Unwind_Context *context, int index,
243 uintptr_t value) {
244 _Unwind_VRS_Set(context, _UVRSC_CORE, (uint32_t)index, _UVRSD_UINT32, &value);
245 }
246
247 _LIBUNWIND_EXPORT_UNWIND_LEVEL1
_Unwind_GetIP(struct _Unwind_Context * context)248 uintptr_t _Unwind_GetIP(struct _Unwind_Context *context) {
249 // remove the thumb-bit before returning
250 return _Unwind_GetGR(context, 15) & (~(uintptr_t)0x1);
251 }
252
253 _LIBUNWIND_EXPORT_UNWIND_LEVEL1
_Unwind_SetIP(struct _Unwind_Context * context,uintptr_t value)254 void _Unwind_SetIP(struct _Unwind_Context *context, uintptr_t value) {
255 uintptr_t thumb_bit = _Unwind_GetGR(context, 15) & ((uintptr_t)0x1);
256 _Unwind_SetGR(context, 15, value | thumb_bit);
257 }
258 #endif // defined(_LIBUNWIND_ARM_EHABI)
259
260 extern uintptr_t _Unwind_GetRegionStart(struct _Unwind_Context *context);
261 extern uintptr_t
262 _Unwind_GetLanguageSpecificData(struct _Unwind_Context *context);
263 #ifdef __USING_SJLJ_EXCEPTIONS__
264 extern _Unwind_Reason_Code
265 _Unwind_SjLj_ForcedUnwind(_Unwind_Exception *exception_object,
266 _Unwind_Stop_Fn stop, void *stop_parameter);
267 #else
268 extern _Unwind_Reason_Code
269 _Unwind_ForcedUnwind(_Unwind_Exception *exception_object,
270 _Unwind_Stop_Fn stop, void *stop_parameter);
271 #endif
272
273 #ifdef __USING_SJLJ_EXCEPTIONS__
274 typedef struct _Unwind_FunctionContext *_Unwind_FunctionContext_t;
275 extern void _Unwind_SjLj_Register(_Unwind_FunctionContext_t fc);
276 extern void _Unwind_SjLj_Unregister(_Unwind_FunctionContext_t fc);
277 #endif
278
279 //
280 // The following are semi-suppoted extensions to the C++ ABI
281 //
282
283 //
284 // called by __cxa_rethrow().
285 //
286 #ifdef __USING_SJLJ_EXCEPTIONS__
287 extern _Unwind_Reason_Code
288 _Unwind_SjLj_Resume_or_Rethrow(_Unwind_Exception *exception_object);
289 #else
290 extern _Unwind_Reason_Code
291 _Unwind_Resume_or_Rethrow(_Unwind_Exception *exception_object);
292 #endif
293
294 // _Unwind_Backtrace() is a gcc extension that walks the stack and calls the
295 // _Unwind_Trace_Fn once per frame until it reaches the bottom of the stack
296 // or the _Unwind_Trace_Fn function returns something other than _URC_NO_REASON.
297 typedef _Unwind_Reason_Code (*_Unwind_Trace_Fn)(struct _Unwind_Context *,
298 void *);
299 extern _Unwind_Reason_Code _Unwind_Backtrace(_Unwind_Trace_Fn, void *);
300
301 // _Unwind_GetCFA is a gcc extension that can be called from within a
302 // personality handler to get the CFA (stack pointer before call) of
303 // current frame.
304 extern uintptr_t _Unwind_GetCFA(struct _Unwind_Context *);
305
306
307 // _Unwind_GetIPInfo is a gcc extension that can be called from within a
308 // personality handler. Similar to _Unwind_GetIP() but also returns in
309 // *ipBefore a non-zero value if the instruction pointer is at or before the
310 // instruction causing the unwind. Normally, in a function call, the IP returned
311 // is the return address which is after the call instruction and may be past the
312 // end of the function containing the call instruction.
313 extern uintptr_t _Unwind_GetIPInfo(struct _Unwind_Context *context,
314 int *ipBefore);
315
316
317 // __register_frame() is used with dynamically generated code to register the
318 // FDE for a generated (JIT) code. The FDE must use pc-rel addressing to point
319 // to its function and optional LSDA.
320 // __register_frame() has existed in all versions of Mac OS X, but in 10.4 and
321 // 10.5 it was buggy and did not actually register the FDE with the unwinder.
322 // In 10.6 and later it does register properly.
323 extern void __register_frame(const void *fde);
324 extern void __deregister_frame(const void *fde);
325
326 // _Unwind_Find_FDE() will locate the FDE if the pc is in some function that has
327 // an associated FDE. Note, Mac OS X 10.6 and later, introduces "compact unwind
328 // info" which the runtime uses in preference to DWARF unwind info. This
329 // function will only work if the target function has an FDE but no compact
330 // unwind info.
331 struct dwarf_eh_bases {
332 uintptr_t tbase;
333 uintptr_t dbase;
334 uintptr_t func;
335 };
336 extern const void *_Unwind_Find_FDE(const void *pc, struct dwarf_eh_bases *);
337
338
339 // This function attempts to find the start (address of first instruction) of
340 // a function given an address inside the function. It only works if the
341 // function has an FDE (DWARF unwind info).
342 // This function is unimplemented on Mac OS X 10.6 and later. Instead, use
343 // _Unwind_Find_FDE() and look at the dwarf_eh_bases.func result.
344 extern void *_Unwind_FindEnclosingFunction(void *pc);
345
346 // Mac OS X does not support text-rel and data-rel addressing so these functions
347 // are unimplemented
348 extern uintptr_t _Unwind_GetDataRelBase(struct _Unwind_Context *context)
349 LIBUNWIND_UNAVAIL;
350 extern uintptr_t _Unwind_GetTextRelBase(struct _Unwind_Context *context)
351 LIBUNWIND_UNAVAIL;
352
353 // Mac OS X 10.4 and 10.5 had implementations of these functions in
354 // libgcc_s.dylib, but they never worked.
355 /// These functions are no longer available on Mac OS X.
356 extern void __register_frame_info_bases(const void *fde, void *ob, void *tb,
357 void *db) LIBUNWIND_UNAVAIL;
358 extern void __register_frame_info(const void *fde, void *ob)
359 LIBUNWIND_UNAVAIL;
360 extern void __register_frame_info_table_bases(const void *fde, void *ob,
361 void *tb, void *db)
362 LIBUNWIND_UNAVAIL;
363 extern void __register_frame_info_table(const void *fde, void *ob)
364 LIBUNWIND_UNAVAIL;
365 extern void __register_frame_table(const void *fde)
366 LIBUNWIND_UNAVAIL;
367 extern void *__deregister_frame_info(const void *fde)
368 LIBUNWIND_UNAVAIL;
369 extern void *__deregister_frame_info_bases(const void *fde)
370 LIBUNWIND_UNAVAIL;
371
372 #ifdef __cplusplus
373 }
374 #endif
375
376 #endif // __UNWIND_H__
377