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 /// Class of foreign exceptions based on unrecognized SEH exceptions. 50 static const uint64_t kSEHExceptionClass = 0x434C4E4753454800; // CLNGSEH\0 51 52 /// Exception cleanup routine used by \c _GCC_specific_handler to 53 /// free foreign exceptions. 54 static void seh_exc_cleanup(_Unwind_Reason_Code urc, _Unwind_Exception *exc) { 55 (void)urc; 56 if (exc->exception_class != kSEHExceptionClass) 57 _LIBUNWIND_ABORT("SEH cleanup called on non-SEH exception"); 58 free(exc); 59 } 60 61 static int _unw_init_seh(unw_cursor_t *cursor, CONTEXT *ctx); 62 static DISPATCHER_CONTEXT *_unw_seh_get_disp_ctx(unw_cursor_t *cursor); 63 static void _unw_seh_set_disp_ctx(unw_cursor_t *cursor, DISPATCHER_CONTEXT *disp); 64 65 /// Common implementation of SEH-style handler functions used by Itanium- 66 /// style frames. Depending on how and why it was called, it may do one of: 67 /// a) Delegate to the given Itanium-style personality function; or 68 /// b) Initiate a collided unwind to halt unwinding. 69 _LIBUNWIND_EXPORT EXCEPTION_DISPOSITION 70 _GCC_specific_handler(PEXCEPTION_RECORD ms_exc, PVOID frame, PCONTEXT ms_ctx, 71 DISPATCHER_CONTEXT *disp, __personality_routine pers) { 72 unw_cursor_t cursor; 73 _Unwind_Exception *exc; 74 _Unwind_Action action; 75 struct _Unwind_Context *ctx = nullptr; 76 _Unwind_Reason_Code urc; 77 uintptr_t retval, target; 78 bool ours = false; 79 80 _LIBUNWIND_TRACE_UNWINDING("_GCC_specific_handler(%#010lx(%lx), %p)", 81 ms_exc->ExceptionCode, ms_exc->ExceptionFlags, 82 (void *)frame); 83 if (ms_exc->ExceptionCode == STATUS_GCC_UNWIND) { 84 if (IS_TARGET_UNWIND(ms_exc->ExceptionFlags)) { 85 // Set up the upper return value (the lower one and the target PC 86 // were set in the call to RtlUnwindEx()) for the landing pad. 87 #ifdef __x86_64__ 88 disp->ContextRecord->Rdx = ms_exc->ExceptionInformation[3]; 89 #elif defined(__arm__) 90 disp->ContextRecord->R1 = ms_exc->ExceptionInformation[3]; 91 #elif defined(__aarch64__) 92 disp->ContextRecord->X1 = ms_exc->ExceptionInformation[3]; 93 #endif 94 } 95 // This is the collided unwind to the landing pad. Nothing to do. 96 return ExceptionContinueSearch; 97 } 98 99 if (ms_exc->ExceptionCode == STATUS_GCC_THROW) { 100 // This is (probably) a libunwind-controlled exception/unwind. Recover the 101 // parameters which we set below, and pass them to the personality function. 102 ours = true; 103 exc = (_Unwind_Exception *)ms_exc->ExceptionInformation[0]; 104 if (!IS_UNWINDING(ms_exc->ExceptionFlags) && ms_exc->NumberParameters > 1) { 105 ctx = (struct _Unwind_Context *)ms_exc->ExceptionInformation[1]; 106 action = (_Unwind_Action)ms_exc->ExceptionInformation[2]; 107 } 108 } else { 109 // Foreign exception. 110 exc = (_Unwind_Exception *)malloc(sizeof(_Unwind_Exception)); 111 exc->exception_class = kSEHExceptionClass; 112 exc->exception_cleanup = seh_exc_cleanup; 113 memset(exc->private_, 0, sizeof(exc->private_)); 114 } 115 if (!ctx) { 116 _unw_init_seh(&cursor, disp->ContextRecord); 117 _unw_seh_set_disp_ctx(&cursor, disp); 118 unw_set_reg(&cursor, UNW_REG_IP, disp->ControlPc-1); 119 ctx = (struct _Unwind_Context *)&cursor; 120 121 if (!IS_UNWINDING(ms_exc->ExceptionFlags)) { 122 if (ours && ms_exc->NumberParameters > 1) 123 action = (_Unwind_Action)(_UA_CLEANUP_PHASE | _UA_FORCE_UNWIND); 124 else 125 action = _UA_SEARCH_PHASE; 126 } else { 127 if (ours && ms_exc->ExceptionInformation[1] == (ULONG_PTR)frame) 128 action = (_Unwind_Action)(_UA_CLEANUP_PHASE | _UA_HANDLER_FRAME); 129 else 130 action = _UA_CLEANUP_PHASE; 131 } 132 } 133 134 _LIBUNWIND_TRACE_UNWINDING("_GCC_specific_handler() calling personality " 135 "function %p(1, %d, %llx, %p, %p)", 136 (void *)pers, action, exc->exception_class, 137 (void *)exc, (void *)ctx); 138 urc = pers(1, action, exc->exception_class, exc, ctx); 139 _LIBUNWIND_TRACE_UNWINDING("_GCC_specific_handler() personality returned %d", urc); 140 switch (urc) { 141 case _URC_CONTINUE_UNWIND: 142 // If we're in phase 2, and the personality routine said to continue 143 // at the target frame, we're in real trouble. 144 if (action & _UA_HANDLER_FRAME) 145 _LIBUNWIND_ABORT("Personality continued unwind at the target frame!"); 146 return ExceptionContinueSearch; 147 case _URC_HANDLER_FOUND: 148 // If we were called by __libunwind_seh_personality(), indicate that 149 // a handler was found; otherwise, initiate phase 2 by unwinding. 150 if (ours && ms_exc->NumberParameters > 1) 151 return 4 /* ExecptionExecuteHandler in mingw */; 152 // This should never happen in phase 2. 153 if (IS_UNWINDING(ms_exc->ExceptionFlags)) 154 _LIBUNWIND_ABORT("Personality indicated exception handler in phase 2!"); 155 exc->private_[1] = (ULONG_PTR)frame; 156 if (ours) { 157 ms_exc->NumberParameters = 4; 158 ms_exc->ExceptionInformation[1] = (ULONG_PTR)frame; 159 } 160 // FIXME: Indicate target frame in foreign case! 161 // phase 2: the clean up phase 162 RtlUnwindEx(frame, (PVOID)disp->ControlPc, ms_exc, exc, ms_ctx, disp->HistoryTable); 163 _LIBUNWIND_ABORT("RtlUnwindEx() failed"); 164 case _URC_INSTALL_CONTEXT: { 165 // If we were called by __libunwind_seh_personality(), indicate that 166 // a handler was found; otherwise, it's time to initiate a collided 167 // unwind to the target. 168 if (ours && !IS_UNWINDING(ms_exc->ExceptionFlags) && ms_exc->NumberParameters > 1) 169 return 4 /* ExecptionExecuteHandler in mingw */; 170 // This should never happen in phase 1. 171 if (!IS_UNWINDING(ms_exc->ExceptionFlags)) 172 _LIBUNWIND_ABORT("Personality installed context during phase 1!"); 173 #ifdef __x86_64__ 174 exc->private_[2] = disp->TargetIp; 175 unw_get_reg(&cursor, UNW_X86_64_RAX, &retval); 176 unw_get_reg(&cursor, UNW_X86_64_RDX, &exc->private_[3]); 177 #elif defined(__arm__) 178 exc->private_[2] = disp->TargetPc; 179 unw_get_reg(&cursor, UNW_ARM_R0, &retval); 180 unw_get_reg(&cursor, UNW_ARM_R1, &exc->private_[3]); 181 #elif defined(__aarch64__) 182 exc->private_[2] = disp->TargetPc; 183 unw_get_reg(&cursor, UNW_ARM64_X0, &retval); 184 unw_get_reg(&cursor, UNW_ARM64_X1, &exc->private_[3]); 185 #endif 186 unw_get_reg(&cursor, UNW_REG_IP, &target); 187 ms_exc->ExceptionCode = STATUS_GCC_UNWIND; 188 #ifdef __x86_64__ 189 ms_exc->ExceptionInformation[2] = disp->TargetIp; 190 #elif defined(__arm__) || defined(__aarch64__) 191 ms_exc->ExceptionInformation[2] = disp->TargetPc; 192 #endif 193 ms_exc->ExceptionInformation[3] = exc->private_[3]; 194 // Give NTRTL some scratch space to keep track of the collided unwind. 195 // Don't use the one that was passed in; we don't want to overwrite the 196 // context in the DISPATCHER_CONTEXT. 197 CONTEXT new_ctx; 198 RtlUnwindEx(frame, (PVOID)target, ms_exc, (PVOID)retval, &new_ctx, disp->HistoryTable); 199 _LIBUNWIND_ABORT("RtlUnwindEx() failed"); 200 } 201 // Anything else indicates a serious problem. 202 default: return ExceptionContinueExecution; 203 } 204 } 205 206 /// Personality function returned by \c unw_get_proc_info() in SEH contexts. 207 /// This is a wrapper that calls the real SEH handler function, which in 208 /// turn (at least, for Itanium-style frames) calls the real Itanium 209 /// personality function (see \c _GCC_specific_handler()). 210 extern "C" _Unwind_Reason_Code 211 __libunwind_seh_personality(int version, _Unwind_Action state, 212 uint64_t klass, _Unwind_Exception *exc, 213 struct _Unwind_Context *context) { 214 (void)version; 215 (void)klass; 216 EXCEPTION_RECORD ms_exc; 217 bool phase2 = (state & (_UA_SEARCH_PHASE|_UA_CLEANUP_PHASE)) == _UA_CLEANUP_PHASE; 218 ms_exc.ExceptionCode = STATUS_GCC_THROW; 219 ms_exc.ExceptionFlags = 0; 220 ms_exc.NumberParameters = 3; 221 ms_exc.ExceptionInformation[0] = (ULONG_PTR)exc; 222 ms_exc.ExceptionInformation[1] = (ULONG_PTR)context; 223 ms_exc.ExceptionInformation[2] = state; 224 DISPATCHER_CONTEXT *disp_ctx = _unw_seh_get_disp_ctx((unw_cursor_t *)context); 225 EXCEPTION_DISPOSITION ms_act = disp_ctx->LanguageHandler(&ms_exc, 226 (PVOID)disp_ctx->EstablisherFrame, 227 disp_ctx->ContextRecord, 228 disp_ctx); 229 switch (ms_act) { 230 case ExceptionContinueSearch: return _URC_CONTINUE_UNWIND; 231 case 4 /*ExceptionExecuteHandler*/: 232 return phase2 ? _URC_INSTALL_CONTEXT : _URC_HANDLER_FOUND; 233 default: 234 return phase2 ? _URC_FATAL_PHASE2_ERROR : _URC_FATAL_PHASE1_ERROR; 235 } 236 } 237 238 static _Unwind_Reason_Code 239 unwind_phase2_forced(unw_context_t *uc, 240 _Unwind_Exception *exception_object, 241 _Unwind_Stop_Fn stop, void *stop_parameter) { 242 unw_cursor_t cursor2; 243 unw_init_local(&cursor2, uc); 244 245 // Walk each frame until we reach where search phase said to stop 246 while (unw_step(&cursor2) > 0) { 247 248 // Update info about this frame. 249 unw_proc_info_t frameInfo; 250 if (unw_get_proc_info(&cursor2, &frameInfo) != UNW_ESUCCESS) { 251 _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): unw_step " 252 "failed => _URC_END_OF_STACK", 253 (void *)exception_object); 254 return _URC_FATAL_PHASE2_ERROR; 255 } 256 257 // When tracing, print state information. 258 if (_LIBUNWIND_TRACING_UNWINDING) { 259 char functionBuf[512]; 260 const char *functionName = functionBuf; 261 unw_word_t offset; 262 if ((unw_get_proc_name(&cursor2, functionBuf, sizeof(functionBuf), 263 &offset) != UNW_ESUCCESS) || 264 (frameInfo.start_ip + offset > frameInfo.end_ip)) 265 functionName = ".anonymous."; 266 _LIBUNWIND_TRACE_UNWINDING( 267 "unwind_phase2_forced(ex_ojb=%p): start_ip=0x%" PRIx64 268 ", func=%s, lsda=0x%" PRIx64 ", personality=0x%" PRIx64, 269 (void *)exception_object, frameInfo.start_ip, functionName, 270 frameInfo.lsda, frameInfo.handler); 271 } 272 273 // Call stop function at each frame. 274 _Unwind_Action action = 275 (_Unwind_Action)(_UA_FORCE_UNWIND | _UA_CLEANUP_PHASE); 276 _Unwind_Reason_Code stopResult = 277 (*stop)(1, action, exception_object->exception_class, exception_object, 278 (struct _Unwind_Context *)(&cursor2), stop_parameter); 279 _LIBUNWIND_TRACE_UNWINDING( 280 "unwind_phase2_forced(ex_ojb=%p): stop function returned %d", 281 (void *)exception_object, stopResult); 282 if (stopResult != _URC_NO_REASON) { 283 _LIBUNWIND_TRACE_UNWINDING( 284 "unwind_phase2_forced(ex_ojb=%p): stopped by stop function", 285 (void *)exception_object); 286 return _URC_FATAL_PHASE2_ERROR; 287 } 288 289 // If there is a personality routine, tell it we are unwinding. 290 if (frameInfo.handler != 0) { 291 __personality_routine p = 292 (__personality_routine)(intptr_t)(frameInfo.handler); 293 _LIBUNWIND_TRACE_UNWINDING( 294 "unwind_phase2_forced(ex_ojb=%p): calling personality function %p", 295 (void *)exception_object, (void *)(uintptr_t)p); 296 _Unwind_Reason_Code personalityResult = 297 (*p)(1, action, exception_object->exception_class, exception_object, 298 (struct _Unwind_Context *)(&cursor2)); 299 switch (personalityResult) { 300 case _URC_CONTINUE_UNWIND: 301 _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): " 302 "personality returned " 303 "_URC_CONTINUE_UNWIND", 304 (void *)exception_object); 305 // Destructors called, continue unwinding 306 break; 307 case _URC_INSTALL_CONTEXT: 308 _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): " 309 "personality returned " 310 "_URC_INSTALL_CONTEXT", 311 (void *)exception_object); 312 // We may get control back if landing pad calls _Unwind_Resume(). 313 unw_resume(&cursor2); 314 break; 315 default: 316 // Personality routine returned an unknown result code. 317 _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): " 318 "personality returned %d, " 319 "_URC_FATAL_PHASE2_ERROR", 320 (void *)exception_object, personalityResult); 321 return _URC_FATAL_PHASE2_ERROR; 322 } 323 } 324 } 325 326 // Call stop function one last time and tell it we've reached the end 327 // of the stack. 328 _LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): calling stop " 329 "function with _UA_END_OF_STACK", 330 (void *)exception_object); 331 _Unwind_Action lastAction = 332 (_Unwind_Action)(_UA_FORCE_UNWIND | _UA_CLEANUP_PHASE | _UA_END_OF_STACK); 333 (*stop)(1, lastAction, exception_object->exception_class, exception_object, 334 (struct _Unwind_Context *)(&cursor2), stop_parameter); 335 336 // Clean up phase did not resume at the frame that the search phase said it 337 // would. 338 return _URC_FATAL_PHASE2_ERROR; 339 } 340 341 /// Called by \c __cxa_throw(). Only returns if there is a fatal error. 342 _LIBUNWIND_EXPORT _Unwind_Reason_Code 343 _Unwind_RaiseException(_Unwind_Exception *exception_object) { 344 _LIBUNWIND_TRACE_API("_Unwind_RaiseException(ex_obj=%p)", 345 (void *)exception_object); 346 347 // Mark that this is a non-forced unwind, so _Unwind_Resume() 348 // can do the right thing. 349 memset(exception_object->private_, 0, sizeof(exception_object->private_)); 350 351 // phase 1: the search phase 352 // We'll let the system do that for us. 353 RaiseException(STATUS_GCC_THROW, 0, 1, (ULONG_PTR *)&exception_object); 354 355 // If we get here, either something went horribly wrong or we reached the 356 // top of the stack. Either way, let libc++abi call std::terminate(). 357 return _URC_END_OF_STACK; 358 } 359 360 /// When \c _Unwind_RaiseException() is in phase2, it hands control 361 /// to the personality function at each frame. The personality 362 /// may force a jump to a landing pad in that function; the landing 363 /// pad code may then call \c _Unwind_Resume() to continue with the 364 /// unwinding. Note: the call to \c _Unwind_Resume() is from compiler 365 /// geneated user code. All other \c _Unwind_* routines are called 366 /// by the C++ runtime \c __cxa_* routines. 367 /// 368 /// Note: re-throwing an exception (as opposed to continuing the unwind) 369 /// is implemented by having the code call \c __cxa_rethrow() which 370 /// in turn calls \c _Unwind_Resume_or_Rethrow(). 371 _LIBUNWIND_EXPORT void 372 _Unwind_Resume(_Unwind_Exception *exception_object) { 373 _LIBUNWIND_TRACE_API("_Unwind_Resume(ex_obj=%p)", (void *)exception_object); 374 375 if (exception_object->private_[0] != 0) { 376 unw_context_t uc; 377 378 unw_getcontext(&uc); 379 unwind_phase2_forced(&uc, exception_object, 380 (_Unwind_Stop_Fn) exception_object->private_[0], 381 (void *)exception_object->private_[4]); 382 } else { 383 // Recover the parameters for the unwind from the exception object 384 // so we can start unwinding again. 385 EXCEPTION_RECORD ms_exc; 386 CONTEXT ms_ctx; 387 UNWIND_HISTORY_TABLE hist; 388 389 memset(&ms_exc, 0, sizeof(ms_exc)); 390 memset(&hist, 0, sizeof(hist)); 391 ms_exc.ExceptionCode = STATUS_GCC_THROW; 392 ms_exc.ExceptionFlags = EXCEPTION_NONCONTINUABLE; 393 ms_exc.NumberParameters = 4; 394 ms_exc.ExceptionInformation[0] = (ULONG_PTR)exception_object; 395 ms_exc.ExceptionInformation[1] = exception_object->private_[1]; 396 ms_exc.ExceptionInformation[2] = exception_object->private_[2]; 397 ms_exc.ExceptionInformation[3] = exception_object->private_[3]; 398 RtlUnwindEx((PVOID)exception_object->private_[1], 399 (PVOID)exception_object->private_[2], &ms_exc, 400 exception_object, &ms_ctx, &hist); 401 } 402 403 // Clients assume _Unwind_Resume() does not return, so all we can do is abort. 404 _LIBUNWIND_ABORT("_Unwind_Resume() can't return"); 405 } 406 407 /// Not used by C++. 408 /// Unwinds stack, calling "stop" function at each frame. 409 /// Could be used to implement \c longjmp(). 410 _LIBUNWIND_EXPORT _Unwind_Reason_Code 411 _Unwind_ForcedUnwind(_Unwind_Exception *exception_object, 412 _Unwind_Stop_Fn stop, void *stop_parameter) { 413 _LIBUNWIND_TRACE_API("_Unwind_ForcedUnwind(ex_obj=%p, stop=%p)", 414 (void *)exception_object, (void *)(uintptr_t)stop); 415 unw_context_t uc; 416 unw_getcontext(&uc); 417 418 // Mark that this is a forced unwind, so _Unwind_Resume() can do 419 // the right thing. 420 exception_object->private_[0] = (uintptr_t) stop; 421 exception_object->private_[4] = (uintptr_t) stop_parameter; 422 423 // do it 424 return unwind_phase2_forced(&uc, exception_object, stop, stop_parameter); 425 } 426 427 /// Called by personality handler during phase 2 to get LSDA for current frame. 428 _LIBUNWIND_EXPORT uintptr_t 429 _Unwind_GetLanguageSpecificData(struct _Unwind_Context *context) { 430 uintptr_t result = (uintptr_t)_unw_seh_get_disp_ctx((unw_cursor_t *)context)->HandlerData; 431 _LIBUNWIND_TRACE_API( 432 "_Unwind_GetLanguageSpecificData(context=%p) => 0x%" PRIxPTR, 433 (void *)context, result); 434 return result; 435 } 436 437 /// Called by personality handler during phase 2 to find the start of the 438 /// function. 439 _LIBUNWIND_EXPORT uintptr_t 440 _Unwind_GetRegionStart(struct _Unwind_Context *context) { 441 DISPATCHER_CONTEXT *disp = _unw_seh_get_disp_ctx((unw_cursor_t *)context); 442 uintptr_t result = (uintptr_t)disp->FunctionEntry->BeginAddress + disp->ImageBase; 443 _LIBUNWIND_TRACE_API("_Unwind_GetRegionStart(context=%p) => 0x%" PRIxPTR, 444 (void *)context, result); 445 return result; 446 } 447 448 static int 449 _unw_init_seh(unw_cursor_t *cursor, CONTEXT *context) { 450 #ifdef _LIBUNWIND_TARGET_X86_64 451 new (reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_x86_64> *>(cursor)) 452 UnwindCursor<LocalAddressSpace, Registers_x86_64>( 453 context, LocalAddressSpace::sThisAddressSpace); 454 auto *co = reinterpret_cast<AbstractUnwindCursor *>(cursor); 455 co->setInfoBasedOnIPRegister(); 456 return UNW_ESUCCESS; 457 #elif defined(_LIBUNWIND_TARGET_ARM) 458 new (reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_arm> *>(cursor)) 459 UnwindCursor<LocalAddressSpace, Registers_arm>( 460 context, LocalAddressSpace::sThisAddressSpace); 461 auto *co = reinterpret_cast<AbstractUnwindCursor *>(cursor); 462 co->setInfoBasedOnIPRegister(); 463 return UNW_ESUCCESS; 464 #elif defined(_LIBUNWIND_TARGET_AARCH64) 465 new (reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_arm64> *>(cursor)) 466 UnwindCursor<LocalAddressSpace, Registers_arm64>( 467 context, LocalAddressSpace::sThisAddressSpace); 468 auto *co = reinterpret_cast<AbstractUnwindCursor *>(cursor); 469 co->setInfoBasedOnIPRegister(); 470 return UNW_ESUCCESS; 471 #else 472 return UNW_EINVAL; 473 #endif 474 } 475 476 static DISPATCHER_CONTEXT * 477 _unw_seh_get_disp_ctx(unw_cursor_t *cursor) { 478 #ifdef _LIBUNWIND_TARGET_X86_64 479 return reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_x86_64> *>(cursor)->getDispatcherContext(); 480 #elif defined(_LIBUNWIND_TARGET_ARM) 481 return reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_arm> *>(cursor)->getDispatcherContext(); 482 #elif defined(_LIBUNWIND_TARGET_AARCH64) 483 return reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_arm64> *>(cursor)->getDispatcherContext(); 484 #else 485 return nullptr; 486 #endif 487 } 488 489 static void 490 _unw_seh_set_disp_ctx(unw_cursor_t *cursor, DISPATCHER_CONTEXT *disp) { 491 #ifdef _LIBUNWIND_TARGET_X86_64 492 reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_x86_64> *>(cursor)->setDispatcherContext(disp); 493 #elif defined(_LIBUNWIND_TARGET_ARM) 494 reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_arm> *>(cursor)->setDispatcherContext(disp); 495 #elif defined(_LIBUNWIND_TARGET_AARCH64) 496 reinterpret_cast<UnwindCursor<LocalAddressSpace, Registers_arm64> *>(cursor)->setDispatcherContext(disp); 497 #endif 498 } 499 500 #endif // defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) 501
