1 //===--------------------------- Unwind-seh.cpp ---------------------------===//
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 // Implements SEH-based Itanium C++ exceptions.
10 //
11 //===----------------------------------------------------------------------===//
12
13 #include "config.h"
14
15 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
16
17 #include <unwind.h>
18
19 #include <stdint.h>
20 #include <stdbool.h>
21 #include <stdlib.h>
22
23 #include <windef.h>
24 #include <excpt.h>
25 #include <winnt.h>
26 #include <ntstatus.h>
27
28 #include "libunwind_ext.h"
29 #include "UnwindCursor.hpp"
30
31 using namespace libunwind;
32
33 #define STATUS_USER_DEFINED (1u << 29)
34
35 #define STATUS_GCC_MAGIC (('G' << 16) | ('C' << 8) | 'C')
36
37 #define MAKE_CUSTOM_STATUS(s, c) \
38 ((NTSTATUS)(((s) << 30) | STATUS_USER_DEFINED | (c)))
39 #define MAKE_GCC_EXCEPTION(c) \
40 MAKE_CUSTOM_STATUS(STATUS_SEVERITY_SUCCESS, STATUS_GCC_MAGIC | ((c) << 24))
41
42 /// SEH exception raised by libunwind when the program calls
43 /// \c _Unwind_RaiseException.
44 #define STATUS_GCC_THROW MAKE_GCC_EXCEPTION(0) // 0x20474343
45 /// SEH exception raised by libunwind to initiate phase 2 of exception
46 /// handling.
47 #define STATUS_GCC_UNWIND MAKE_GCC_EXCEPTION(1) // 0x21474343
48
49 static int __unw_init_seh(unw_cursor_t *cursor, CONTEXT *ctx);
50 static DISPATCHER_CONTEXT *__unw_seh_get_disp_ctx(unw_cursor_t *cursor);
51 static void __unw_seh_set_disp_ctx(unw_cursor_t *cursor,
52 DISPATCHER_CONTEXT *disp);
53
54 /// Common implementation of SEH-style handler functions used by Itanium-
55 /// style frames. Depending on how and why it was called, it may do one of:
56 /// a) Delegate to the given Itanium-style personality function; or
57 /// b) Initiate a collided unwind to halt unwinding.
58 _LIBUNWIND_EXPORT EXCEPTION_DISPOSITION
_GCC_specific_handler(PEXCEPTION_RECORD ms_exc,PVOID frame,PCONTEXT ms_ctx,DISPATCHER_CONTEXT * disp,_Unwind_Personality_Fn pers)59 _GCC_specific_handler(PEXCEPTION_RECORD ms_exc, PVOID frame, PCONTEXT ms_ctx,
60 DISPATCHER_CONTEXT *disp, _Unwind_Personality_Fn pers) {
61 unw_cursor_t cursor;
62 _Unwind_Exception *exc;
63 _Unwind_Action action;
64 struct _Unwind_Context *ctx = nullptr;
65 _Unwind_Reason_Code urc;
66 uintptr_t retval, target;
67 bool ours = false;
68
69 _LIBUNWIND_TRACE_UNWINDING("_GCC_specific_handler(%#010lx(%lx), %p)",
70 ms_exc->ExceptionCode, ms_exc->ExceptionFlags,
71 (void *)frame);
72 if (ms_exc->ExceptionCode == STATUS_GCC_UNWIND) {
73 if (IS_TARGET_UNWIND(ms_exc->ExceptionFlags)) {
74 // Set up the upper return value (the lower one and the target PC
75 // were set in the call to RtlUnwindEx()) for the landing pad.
76 #ifdef __x86_64__
77 disp->ContextRecord->Rdx = ms_exc->ExceptionInformation[3];
78 #elif defined(__arm__)
79 disp->ContextRecord->R1 = ms_exc->ExceptionInformation[3];
80 #elif defined(__aarch64__)
81 disp->ContextRecord->X1 = ms_exc->ExceptionInformation[3];
82 #endif
83 }
84 // This is the collided unwind to the landing pad. Nothing to do.
85 return ExceptionContinueSearch;
86 }
87
88 if (ms_exc->ExceptionCode == STATUS_GCC_THROW) {
89 // This is (probably) a libunwind-controlled exception/unwind. Recover the
90 // parameters which we set below, and pass them to the personality function.
91 ours = true;
92 exc = (_Unwind_Exception *)ms_exc->ExceptionInformation[0];
93 if (!IS_UNWINDING(ms_exc->ExceptionFlags) && ms_exc->NumberParameters > 1) {
94 ctx = (struct _Unwind_Context *)ms_exc->ExceptionInformation[1];
95 action = (_Unwind_Action)ms_exc->ExceptionInformation[2];
96 }
97 } else {
98 // Foreign exception.
99 // We can't interact with them (we don't know the original target frame
100 // that we should pass on to RtlUnwindEx in _Unwind_Resume), so just
101 // pass without calling our destructors here.
102 return ExceptionContinueSearch;
103 }
104 if (!ctx) {
105 __unw_init_seh(&cursor, disp->ContextRecord);
106 __unw_seh_set_disp_ctx(&cursor, disp);
107 __unw_set_reg(&cursor, UNW_REG_IP, disp->ControlPc - 1);
108 ctx = (struct _Unwind_Context *)&cursor;
109
110 if (!IS_UNWINDING(ms_exc->ExceptionFlags)) {
111 if (ours && ms_exc->NumberParameters > 1)
112 action = (_Unwind_Action)(_UA_CLEANUP_PHASE | _UA_FORCE_UNWIND);
113 else
114 action = _UA_SEARCH_PHASE;
115 } else {
116 if (ours && ms_exc->ExceptionInformation[1] == (ULONG_PTR)frame)
117 action = (_Unwind_Action)(_UA_CLEANUP_PHASE | _UA_HANDLER_FRAME);
118 else
119 action = _UA_CLEANUP_PHASE;
120 }
121 }
122
123 _LIBUNWIND_TRACE_UNWINDING("_GCC_specific_handler() calling personality "
124 "function %p(1, %d, %llx, %p, %p)",
125 (void *)pers, action, exc->exception_class,
126 (void *)exc, (void *)ctx);
127 urc = pers(1, action, exc->exception_class, exc, ctx);
128 _LIBUNWIND_TRACE_UNWINDING("_GCC_specific_handler() personality returned %d", urc);
129 switch (urc) {
130 case _URC_CONTINUE_UNWIND:
131 // If we're in phase 2, and the personality routine said to continue
132 // at the target frame, we're in real trouble.
133 if (action & _UA_HANDLER_FRAME)
134 _LIBUNWIND_ABORT("Personality continued unwind at the target frame!");
135 return ExceptionContinueSearch;
136 case _URC_HANDLER_FOUND:
137 // If we were called by __libunwind_seh_personality(), indicate that
138 // a handler was found; otherwise, initiate phase 2 by unwinding.
139 if (ours && ms_exc->NumberParameters > 1)
140 return 4 /* ExecptionExecuteHandler in mingw */;
141 // This should never happen in phase 2.
142 if (IS_UNWINDING(ms_exc->ExceptionFlags))
143 _LIBUNWIND_ABORT("Personality indicated exception handler in phase 2!");
144 exc->private_[1] = (ULONG_PTR)frame;
145 if (ours) {
146 ms_exc->NumberParameters = 4;
147 ms_exc->ExceptionInformation[1] = (ULONG_PTR)frame;
148 }
149 // FIXME: Indicate target frame in foreign case!
150 // phase 2: the clean up phase
151 RtlUnwindEx(frame, (PVOID)disp->ControlPc, ms_exc, exc, ms_ctx, disp->HistoryTable);
152 _LIBUNWIND_ABORT("RtlUnwindEx() failed");
153 case _URC_INSTALL_CONTEXT: {
154 // If we were called by __libunwind_seh_personality(), indicate that
155 // a handler was found; otherwise, it's time to initiate a collided
156 // unwind to the target.
157 if (ours && !IS_UNWINDING(ms_exc->ExceptionFlags) && ms_exc->NumberParameters > 1)
158 return 4 /* ExecptionExecuteHandler in mingw */;
159 // This should never happen in phase 1.
160 if (!IS_UNWINDING(ms_exc->ExceptionFlags))
161 _LIBUNWIND_ABORT("Personality installed context during phase 1!");
162 #ifdef __x86_64__
163 exc->private_[2] = disp->TargetIp;
164 __unw_get_reg(&cursor, UNW_X86_64_RAX, &retval);
165 __unw_get_reg(&cursor, UNW_X86_64_RDX, &exc->private_[3]);
166 #elif defined(__arm__)
167 exc->private_[2] = disp->TargetPc;
168 __unw_get_reg(&cursor, UNW_ARM_R0, &retval);
169 __unw_get_reg(&cursor, UNW_ARM_R1, &exc->private_[3]);
170 #elif defined(__aarch64__)
171 exc->private_[2] = disp->TargetPc;
172 __unw_get_reg(&cursor, UNW_ARM64_X0, &retval);
173 __unw_get_reg(&cursor, UNW_ARM64_X1, &exc->private_[3]);
174 #endif
175 __unw_get_reg(&cursor, UNW_REG_IP, &target);
176 ms_exc->ExceptionCode = STATUS_GCC_UNWIND;
177 #ifdef __x86_64__
178 ms_exc->ExceptionInformation[2] = disp->TargetIp;
179 #elif defined(__arm__) || defined(__aarch64__)
180 ms_exc->ExceptionInformation[2] = disp->TargetPc;
181 #endif
182 ms_exc->ExceptionInformation[3] = exc->private_[3];
183 // Give NTRTL some scratch space to keep track of the collided unwind.
184 // Don't use the one that was passed in; we don't want to overwrite the
185 // context in the DISPATCHER_CONTEXT.
186 CONTEXT new_ctx;
187 RtlUnwindEx(frame, (PVOID)target, ms_exc, (PVOID)retval, &new_ctx, disp->HistoryTable);
188 _LIBUNWIND_ABORT("RtlUnwindEx() failed");
189 }
190 // Anything else indicates a serious problem.
191 default: return ExceptionContinueExecution;
192 }
193 }
194
195 /// Personality function returned by \c __unw_get_proc_info() in SEH contexts.
196 /// This is a wrapper that calls the real SEH handler function, which in
197 /// turn (at least, for Itanium-style frames) calls the real Itanium
198 /// personality function (see \c _GCC_specific_handler()).
199 extern "C" _Unwind_Reason_Code
__libunwind_seh_personality(int version,_Unwind_Action state,uint64_t klass,_Unwind_Exception * exc,struct _Unwind_Context * context)200 __libunwind_seh_personality(int version, _Unwind_Action state,
201 uint64_t klass, _Unwind_Exception *exc,
202 struct _Unwind_Context *context) {
203 (void)version;
204 (void)klass;
205 EXCEPTION_RECORD ms_exc;
206 bool phase2 = (state & (_UA_SEARCH_PHASE|_UA_CLEANUP_PHASE)) == _UA_CLEANUP_PHASE;
207 ms_exc.ExceptionCode = STATUS_GCC_THROW;
208 ms_exc.ExceptionFlags = 0;
209 ms_exc.NumberParameters = 3;
210 ms_exc.ExceptionInformation[0] = (ULONG_PTR)exc;
211 ms_exc.ExceptionInformation[1] = (ULONG_PTR)context;
212 ms_exc.ExceptionInformation[2] = state;
213 DISPATCHER_CONTEXT *disp_ctx =
214 __unw_seh_get_disp_ctx((unw_cursor_t *)context);
215 EXCEPTION_DISPOSITION ms_act = disp_ctx->LanguageHandler(&ms_exc,
216 (PVOID)disp_ctx->EstablisherFrame,
217 disp_ctx->ContextRecord,
218 disp_ctx);
219 switch (ms_act) {
220 case ExceptionContinueSearch: return _URC_CONTINUE_UNWIND;
221 case 4 /*ExceptionExecuteHandler*/:
222 return phase2 ? _URC_INSTALL_CONTEXT : _URC_HANDLER_FOUND;
223 default:
224 return phase2 ? _URC_FATAL_PHASE2_ERROR : _URC_FATAL_PHASE1_ERROR;
225 }
226 }
227
228 static _Unwind_Reason_Code
unwind_phase2_forced(unw_context_t * uc,_Unwind_Exception * exception_object,_Unwind_Stop_Fn stop,void * stop_parameter)229 unwind_phase2_forced(unw_context_t *uc,
230 _Unwind_Exception *exception_object,
231 _Unwind_Stop_Fn stop, void *stop_parameter) {
232 unw_cursor_t cursor2;
233 __unw_init_local(&cursor2, uc);
234
235 // Walk each frame until we reach where search phase said to stop
236 while (__unw_step(&cursor2) > 0) {
237
238 // Update info about this frame.
239 unw_proc_info_t frameInfo;
240 if (__unw_get_proc_info(&cursor2, &frameInfo) != UNW_ESUCCESS) {
241 _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): __unw_step "
242 "failed => _URC_END_OF_STACK",
243 (void *)exception_object);
244 return _URC_FATAL_PHASE2_ERROR;
245 }
246
247 // When tracing, print state information.
248 if (_LIBUNWIND_TRACING_UNWINDING) {
249 char functionBuf[512];
250 const char *functionName = functionBuf;
251 unw_word_t offset;
252 if ((__unw_get_proc_name(&cursor2, functionBuf, sizeof(functionBuf),
253 &offset) != UNW_ESUCCESS) ||
254 (frameInfo.start_ip + offset > frameInfo.end_ip))
255 functionName = ".anonymous.";
256 _LIBUNWIND_TRACE_UNWINDING(
257 "unwind_phase2_forced(ex_ojb=%p): start_ip=0x%" PRIx64
258 ", func=%s, lsda=0x%" PRIx64 ", personality=0x%" PRIx64,
259 (void *)exception_object, frameInfo.start_ip, functionName,
260 frameInfo.lsda, frameInfo.handler);
261 }
262
263 // Call stop function at each frame.
264 _Unwind_Action action =
265 (_Unwind_Action)(_UA_FORCE_UNWIND | _UA_CLEANUP_PHASE);
266 _Unwind_Reason_Code stopResult =
267 (*stop)(1, action, exception_object->exception_class, exception_object,
268 (struct _Unwind_Context *)(&cursor2), stop_parameter);
269 _LIBUNWIND_TRACE_UNWINDING(
270 "unwind_phase2_forced(ex_ojb=%p): stop function returned %d",
271 (void *)exception_object, stopResult);
272 if (stopResult != _URC_NO_REASON) {
273 _LIBUNWIND_TRACE_UNWINDING(
274 "unwind_phase2_forced(ex_ojb=%p): stopped by stop function",
275 (void *)exception_object);
276 return _URC_FATAL_PHASE2_ERROR;
277 }
278
279 // If there is a personality routine, tell it we are unwinding.
280 if (frameInfo.handler != 0) {
281 _Unwind_Personality_Fn p =
282 (_Unwind_Personality_Fn)(intptr_t)(frameInfo.handler);
283 _LIBUNWIND_TRACE_UNWINDING(
284 "unwind_phase2_forced(ex_ojb=%p): calling personality function %p",
285 (void *)exception_object, (void *)(uintptr_t)p);
286 _Unwind_Reason_Code personalityResult =
287 (*p)(1, action, exception_object->exception_class, exception_object,
288 (struct _Unwind_Context *)(&cursor2));
289 switch (personalityResult) {
290 case _URC_CONTINUE_UNWIND:
291 _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): "
292 "personality returned "
293 "_URC_CONTINUE_UNWIND",
294 (void *)exception_object);
295 // Destructors called, continue unwinding
296 break;
297 case _URC_INSTALL_CONTEXT:
298 _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): "
299 "personality returned "
300 "_URC_INSTALL_CONTEXT",
301 (void *)exception_object);
302 // We may get control back if landing pad calls _Unwind_Resume().
303 __unw_resume(&cursor2);
304 break;
305 default:
306 // Personality routine returned an unknown result code.
307 _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): "
308 "personality returned %d, "
309 "_URC_FATAL_PHASE2_ERROR",
310 (void *)exception_object, personalityResult);
311 return _URC_FATAL_PHASE2_ERROR;
312 }
313 }
314 }
315
316 // Call stop function one last time and tell it we've reached the end
317 // of the stack.
318 _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): calling stop "
319 "function with _UA_END_OF_STACK",
320 (void *)exception_object);
321 _Unwind_Action lastAction =
322 (_Unwind_Action)(_UA_FORCE_UNWIND | _UA_CLEANUP_PHASE | _UA_END_OF_STACK);
323 (*stop)(1, lastAction, exception_object->exception_class, exception_object,
324 (struct _Unwind_Context *)(&cursor2), stop_parameter);
325
326 // Clean up phase did not resume at the frame that the search phase said it
327 // would.
328 return _URC_FATAL_PHASE2_ERROR;
329 }
330
331 /// Called by \c __cxa_throw(). Only returns if there is a fatal error.
332 _LIBUNWIND_EXPORT _Unwind_Reason_Code
_Unwind_RaiseException(_Unwind_Exception * exception_object)333 _Unwind_RaiseException(_Unwind_Exception *exception_object) {
334 _LIBUNWIND_TRACE_API("_Unwind_RaiseException(ex_obj=%p)",
335 (void *)exception_object);
336
337 // Mark that this is a non-forced unwind, so _Unwind_Resume()
338 // can do the right thing.
339 memset(exception_object->private_, 0, sizeof(exception_object->private_));
340
341 // phase 1: the search phase
342 // We'll let the system do that for us.
343 RaiseException(STATUS_GCC_THROW, 0, 1, (ULONG_PTR *)&exception_object);
344
345 // If we get here, either something went horribly wrong or we reached the
346 // top of the stack. Either way, let libc++abi call std::terminate().
347 return _URC_END_OF_STACK;
348 }
349
350 /// When \c _Unwind_RaiseException() is in phase2, it hands control
351 /// to the personality function at each frame. The personality
352 /// may force a jump to a landing pad in that function; the landing
353 /// pad code may then call \c _Unwind_Resume() to continue with the
354 /// unwinding. Note: the call to \c _Unwind_Resume() is from compiler
355 /// geneated user code. All other \c _Unwind_* routines are called
356 /// by the C++ runtime \c __cxa_* routines.
357 ///
358 /// Note: re-throwing an exception (as opposed to continuing the unwind)
359 /// is implemented by having the code call \c __cxa_rethrow() which
360 /// in turn calls \c _Unwind_Resume_or_Rethrow().
361 _LIBUNWIND_EXPORT void
_Unwind_Resume(_Unwind_Exception * exception_object)362 _Unwind_Resume(_Unwind_Exception *exception_object) {
363 _LIBUNWIND_TRACE_API("_Unwind_Resume(ex_obj=%p)", (void *)exception_object);
364
365 if (exception_object->private_[0] != 0) {
366 unw_context_t uc;
367
368 __unw_getcontext(&uc);
369 unwind_phase2_forced(&uc, exception_object,
370 (_Unwind_Stop_Fn) exception_object->private_[0],
371 (void *)exception_object->private_[4]);
372 } else {
373 // Recover the parameters for the unwind from the exception object
374 // so we can start unwinding again.
375 EXCEPTION_RECORD ms_exc;
376 CONTEXT ms_ctx;
377 UNWIND_HISTORY_TABLE hist;
378
379 memset(&ms_exc, 0, sizeof(ms_exc));
380 memset(&hist, 0, sizeof(hist));
381 ms_exc.ExceptionCode = STATUS_GCC_THROW;
382 ms_exc.ExceptionFlags = EXCEPTION_NONCONTINUABLE;
383 ms_exc.NumberParameters = 4;
384 ms_exc.ExceptionInformation[0] = (ULONG_PTR)exception_object;
385 ms_exc.ExceptionInformation[1] = exception_object->private_[1];
386 ms_exc.ExceptionInformation[2] = exception_object->private_[2];
387 ms_exc.ExceptionInformation[3] = exception_object->private_[3];
388 RtlUnwindEx((PVOID)exception_object->private_[1],
389 (PVOID)exception_object->private_[2], &ms_exc,
390 exception_object, &ms_ctx, &hist);
391 }
392
393 // Clients assume _Unwind_Resume() does not return, so all we can do is abort.
394 _LIBUNWIND_ABORT("_Unwind_Resume() can't return");
395 }
396
397 /// Not used by C++.
398 /// Unwinds stack, calling "stop" function at each frame.
399 /// Could be used to implement \c longjmp().
400 _LIBUNWIND_EXPORT _Unwind_Reason_Code
_Unwind_ForcedUnwind(_Unwind_Exception * exception_object,_Unwind_Stop_Fn stop,void * stop_parameter)401 _Unwind_ForcedUnwind(_Unwind_Exception *exception_object,
402 _Unwind_Stop_Fn stop, void *stop_parameter) {
403 _LIBUNWIND_TRACE_API("_Unwind_ForcedUnwind(ex_obj=%p, stop=%p)",
404 (void *)exception_object, (void *)(uintptr_t)stop);
405 unw_context_t uc;
406 __unw_getcontext(&uc);
407
408 // Mark that this is a forced unwind, so _Unwind_Resume() can do
409 // the right thing.
410 exception_object->private_[0] = (uintptr_t) stop;
411 exception_object->private_[4] = (uintptr_t) stop_parameter;
412
413 // do it
414 return unwind_phase2_forced(&uc, exception_object, stop, stop_parameter);
415 }
416
417 /// Called by personality handler during phase 2 to get LSDA for current frame.
418 _LIBUNWIND_EXPORT uintptr_t
_Unwind_GetLanguageSpecificData(struct _Unwind_Context * context)419 _Unwind_GetLanguageSpecificData(struct _Unwind_Context *context) {
420 uintptr_t result =
421 (uintptr_t)__unw_seh_get_disp_ctx((unw_cursor_t *)context)->HandlerData;
422 _LIBUNWIND_TRACE_API(
423 "_Unwind_GetLanguageSpecificData(context=%p) => 0x%" PRIxPTR,
424 (void *)context, result);
425 return result;
426 }
427
428 /// Called by personality handler during phase 2 to find the start of the
429 /// function.
430 _LIBUNWIND_EXPORT uintptr_t
_Unwind_GetRegionStart(struct _Unwind_Context * context)431 _Unwind_GetRegionStart(struct _Unwind_Context *context) {
432 DISPATCHER_CONTEXT *disp = __unw_seh_get_disp_ctx((unw_cursor_t *)context);
433 uintptr_t result = (uintptr_t)disp->FunctionEntry->BeginAddress + disp->ImageBase;
434 _LIBUNWIND_TRACE_API("_Unwind_GetRegionStart(context=%p) => 0x%" PRIxPTR,
435 (void *)context, result);
436 return result;
437 }
438
__unw_init_seh(unw_cursor_t * cursor,CONTEXT * context)439 static int __unw_init_seh(unw_cursor_t *cursor, CONTEXT *context) {
440 #ifdef _LIBUNWIND_TARGET_X86_64
441 new (reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_x86_64> *>(cursor))
442 UnwindCursor<LocalAddressSpace, Registers_x86_64>(
443 context, LocalAddressSpace::sThisAddressSpace);
444 auto *co = reinterpret_cast<AbstractUnwindCursor *>(cursor);
445 co->setInfoBasedOnIPRegister();
446 return UNW_ESUCCESS;
447 #elif defined(_LIBUNWIND_TARGET_ARM)
448 new (reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_arm> *>(cursor))
449 UnwindCursor<LocalAddressSpace, Registers_arm>(
450 context, LocalAddressSpace::sThisAddressSpace);
451 auto *co = reinterpret_cast<AbstractUnwindCursor *>(cursor);
452 co->setInfoBasedOnIPRegister();
453 return UNW_ESUCCESS;
454 #elif defined(_LIBUNWIND_TARGET_AARCH64)
455 new (reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_arm64> *>(cursor))
456 UnwindCursor<LocalAddressSpace, Registers_arm64>(
457 context, LocalAddressSpace::sThisAddressSpace);
458 auto *co = reinterpret_cast<AbstractUnwindCursor *>(cursor);
459 co->setInfoBasedOnIPRegister();
460 return UNW_ESUCCESS;
461 #else
462 return UNW_EINVAL;
463 #endif
464 }
465
__unw_seh_get_disp_ctx(unw_cursor_t * cursor)466 static DISPATCHER_CONTEXT *__unw_seh_get_disp_ctx(unw_cursor_t *cursor) {
467 #ifdef _LIBUNWIND_TARGET_X86_64
468 return reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_x86_64> *>(cursor)->getDispatcherContext();
469 #elif defined(_LIBUNWIND_TARGET_ARM)
470 return reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_arm> *>(cursor)->getDispatcherContext();
471 #elif defined(_LIBUNWIND_TARGET_AARCH64)
472 return reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_arm64> *>(cursor)->getDispatcherContext();
473 #else
474 return nullptr;
475 #endif
476 }
477
__unw_seh_set_disp_ctx(unw_cursor_t * cursor,DISPATCHER_CONTEXT * disp)478 static void __unw_seh_set_disp_ctx(unw_cursor_t *cursor,
479 DISPATCHER_CONTEXT *disp) {
480 #ifdef _LIBUNWIND_TARGET_X86_64
481 reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_x86_64> *>(cursor)->setDispatcherContext(disp);
482 #elif defined(_LIBUNWIND_TARGET_ARM)
483 reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_arm> *>(cursor)->setDispatcherContext(disp);
484 #elif defined(_LIBUNWIND_TARGET_AARCH64)
485 reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_arm64> *>(cursor)->setDispatcherContext(disp);
486 #endif
487 }
488
489 #endif // defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
490