static _Unwind_Reason_Code
unwind_phase1(struct _Unwind_Exception *exception_object) {
_Unwind_FunctionContext_t c = __Unwind_SjLj_GetTopOfFunctionStack();
_LIBUNWIND_TRACE_UNWINDING("unwind_phase1: initial function-context=%p\n", c);
// walk each frame looking for a place to stop
for (bool handlerNotFound = true; handlerNotFound; c = c->prev) {
// check for no more frames
if (c == NULL) {
_LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): reached "
"bottom => _URC_END_OF_STACK\n",
exception_object);
return _URC_END_OF_STACK;
}
_LIBUNWIND_TRACE_UNWINDING("unwind_phase1: function-context=%p\n", c);
// if there is a personality routine, ask it if it will want to stop at this
// frame
if (c->personality != NULL) {
_LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): calling "
"personality function %p\n",
exception_object, c->personality);
_Unwind_Reason_Code personalityResult = (*c->personality)(
1, _UA_SEARCH_PHASE, exception_object->exception_class,
exception_object, (struct _Unwind_Context *)c);
switch (personalityResult) {
case _URC_HANDLER_FOUND:
// found a catch clause or locals that need destructing in this frame
// stop search and remember function context
handlerNotFound = false;
exception_object->private_2 = (uintptr_t) c;
_LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): "
"_URC_HANDLER_FOUND\n", exception_object);
return _URC_NO_REASON;
case _URC_CONTINUE_UNWIND:
_LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): "
"_URC_CONTINUE_UNWIND\n", exception_object);
// continue unwinding
break;
default:
// something went wrong
_LIBUNWIND_TRACE_UNWINDING(
"unwind_phase1(ex_ojb=%p): _URC_FATAL_PHASE1_ERROR\n",
exception_object);
return _URC_FATAL_PHASE1_ERROR;
}
}
}
return _URC_NO_REASON;
}
static _Unwind_Reason_Code
unwind_phase2_forced(struct _Unwind_Exception *exception_object,
_Unwind_Stop_Fn stop, void *stop_parameter) {
// walk each frame until we reach where search phase said to stop
_Unwind_FunctionContext_t c = __Unwind_SjLj_GetTopOfFunctionStack();
while (true) {
// get next frame (skip over first which is _Unwind_RaiseException)
if (c == NULL) {
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): unw_step() reached "
"bottom => _URC_END_OF_STACK\n",
exception_object);
return _URC_END_OF_STACK;
}
// call stop function at each frame
_Unwind_Action action =
(_Unwind_Action)(_UA_FORCE_UNWIND | _UA_CLEANUP_PHASE);
_Unwind_Reason_Code stopResult =
(*stop)(1, action, exception_object->exception_class, exception_object,
(struct _Unwind_Context *)c, stop_parameter);
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): "
"stop function returned %d\n",
exception_object, stopResult);
if (stopResult != _URC_NO_REASON) {
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): "
"stopped by stop function\n",
exception_object);
return _URC_FATAL_PHASE2_ERROR;
}
// if there is a personality routine, tell it we are unwinding
if (c->personality != NULL) {
__personality_routine p = (__personality_routine) c->personality;
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): "
"calling personality function %p\n",
exception_object, p);
_Unwind_Reason_Code personalityResult =
(*p)(1, action, exception_object->exception_class, exception_object,
(struct _Unwind_Context *)c);
switch (personalityResult) {
case _URC_CONTINUE_UNWIND:
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): "
"personality returned _URC_CONTINUE_UNWIND\n",
exception_object);
// destructors called, continue unwinding
break;
case _URC_INSTALL_CONTEXT:
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): "
"personality returned _URC_INSTALL_CONTEXT\n",
exception_object);
// we may get control back if landing pad calls _Unwind_Resume()
__Unwind_SjLj_SetTopOfFunctionStack(c);
__builtin_longjmp(c->jbuf, 1);
break;
default:
// something went wrong
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): "
"personality returned %d, "
"_URC_FATAL_PHASE2_ERROR\n",
exception_object, personalityResult);
return _URC_FATAL_PHASE2_ERROR;
}
}
c = c->prev;
}
// call stop function one last time and tell it we've reached the end of the
// stack
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): calling stop "
"function with _UA_END_OF_STACK\n",
exception_object);
_Unwind_Action lastAction =
(_Unwind_Action)(_UA_FORCE_UNWIND | _UA_CLEANUP_PHASE | _UA_END_OF_STACK);
(*stop)(1, lastAction, exception_object->exception_class, exception_object,
(struct _Unwind_Context *)c, stop_parameter);
// clean up phase did not resume at the frame that the search phase said it
// would
return _URC_FATAL_PHASE2_ERROR;
}
void __Unwind_SjLj_SetTopOfFunctionStack(struct _Unwind_FunctionContext *fc) {
_LIBUNWIND_TRACE_UNWINDING("__Unwind_SjLj_GetTopOfFunctionStack: %p\n", fc);
pthread_setspecific(PTHREAD_KEY_LIBCXX_SJLJ, fc);
}
static _Unwind_Reason_Code
unwind_phase2(struct _Unwind_Exception *exception_object) {
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p)\n", exception_object);
// walk each frame until we reach where search phase said to stop
_Unwind_FunctionContext_t c = __Unwind_SjLj_GetTopOfFunctionStack();
while (true) {
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2s(ex_ojb=%p): context=%p\n",
exception_object, c);
// check for no more frames
if (c == NULL) {
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): unw_step() reached "
"bottom => _URC_END_OF_STACK\n",
exception_object);
return _URC_END_OF_STACK;
}
// if there is a personality routine, tell it we are unwinding
if (c->personality != NULL) {
_Unwind_Action action = _UA_CLEANUP_PHASE;
if ((uintptr_t) c == exception_object->private_2)
action = (_Unwind_Action)(
_UA_CLEANUP_PHASE |
_UA_HANDLER_FRAME); // tell personality this was the frame it marked
// in phase 1
_Unwind_Reason_Code personalityResult =
(*c->personality)(1, action, exception_object->exception_class,
exception_object, (struct _Unwind_Context *)c);
switch (personalityResult) {
case _URC_CONTINUE_UNWIND:
// continue unwinding
_LIBUNWIND_TRACE_UNWINDING(
"unwind_phase2(ex_ojb=%p): _URC_CONTINUE_UNWIND\n",
exception_object);
if ((uintptr_t) c == exception_object->private_2) {
// phase 1 said we would stop at this frame, but we did not...
_LIBUNWIND_ABORT("during phase1 personality function said it would "
"stop here, but now if phase2 it did not stop here");
}
break;
case _URC_INSTALL_CONTEXT:
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): "
"_URC_INSTALL_CONTEXT, will resume at "
"landing pad %p\n",
exception_object, c->jbuf[1]);
// personality routine says to transfer control to landing pad
// we may get control back if landing pad calls _Unwind_Resume()
__Unwind_SjLj_SetTopOfFunctionStack(c);
__builtin_longjmp(c->jbuf, 1);
// unw_resume() only returns if there was an error
return _URC_FATAL_PHASE2_ERROR;
default:
// something went wrong
_LIBUNWIND_DEBUG_LOG("personality function returned unknown result %d",
personalityResult);
return _URC_FATAL_PHASE2_ERROR;
}
}
c = c->prev;
}
// clean up phase did not resume at the frame that the search phase said it
// would
return _URC_FATAL_PHASE2_ERROR;
}
static _Unwind_Reason_Code
unwind_phase1(unw_context_t *uc, struct _Unwind_Exception *exception_object) {
// EHABI #7.3 discusses preserving the VRS in a "temporary VRS" during
// phase 1 and then restoring it to the "primary VRS" for phase 2. The
// effect is phase 2 doesn't see any of the VRS manipulations from phase 1.
// In this implementation, the phases don't share the VRS backing store.
// Instead, they are passed the original |uc| and they create a new VRS
// from scratch thus achieving the same effect.
unw_cursor_t cursor1;
unw_init_local(&cursor1, uc);
// Walk each frame looking for a place to stop.
for (bool handlerNotFound = true; handlerNotFound;) {
// Ask libuwind to get next frame (skip over first which is
// _Unwind_RaiseException).
int stepResult = unw_step(&cursor1);
if (stepResult == 0) {
_LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): unw_step() reached "
"bottom => _URC_END_OF_STACK\n",
exception_object);
return _URC_END_OF_STACK;
} else if (stepResult < 0) {
_LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): unw_step failed => "
"_URC_FATAL_PHASE1_ERROR\n",
exception_object);
return _URC_FATAL_PHASE1_ERROR;
}
// See if frame has code to run (has personality routine).
unw_proc_info_t frameInfo;
unw_word_t sp;
if (unw_get_proc_info(&cursor1, &frameInfo) != UNW_ESUCCESS) {
_LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): unw_get_proc_info "
"failed => _URC_FATAL_PHASE1_ERROR\n",
exception_object);
return _URC_FATAL_PHASE1_ERROR;
}
// When tracing, print state information.
if (_LIBUNWIND_TRACING_UNWINDING) {
char functionName[512];
unw_word_t offset;
if ((unw_get_proc_name(&cursor1, functionName, 512, &offset) !=
UNW_ESUCCESS) || (frameInfo.start_ip + offset > frameInfo.end_ip))
strcpy(functionName, ".anonymous.");
unw_word_t pc;
unw_get_reg(&cursor1, UNW_REG_IP, &pc);
_LIBUNWIND_TRACE_UNWINDING(
"unwind_phase1(ex_ojb=%p): pc=0x%llX, start_ip=0x%lX, func=%s, "
"lsda=0x%llX, personality=0x%llX\n",
exception_object, pc, frameInfo.start_ip, functionName,
frameInfo.lsda, frameInfo.handler);
}
// If there is a personality routine, ask it if it will want to stop at
// this frame.
if (frameInfo.handler != 0) {
__personality_routine p =
(__personality_routine)(long)(frameInfo.handler);
_LIBUNWIND_TRACE_UNWINDING(
"unwind_phase1(ex_ojb=%p): calling personality function %p\n",
exception_object, p);
struct _Unwind_Context *context = (struct _Unwind_Context *)(&cursor1);
#ifdef __arm__
exception_object->pr_cache.fnstart = frameInfo.start_ip;
exception_object->pr_cache.ehtp = (_Unwind_EHT_Header *)frameInfo.unwind_info;
exception_object->pr_cache.additional = frameInfo.flags;
_Unwind_Reason_Code personalityResult =
(*p)(_US_VIRTUAL_UNWIND_FRAME, exception_object, context);
#else
_Unwind_Reason_Code personalityResult =
(*p)(1, _UA_SEARCH_PHASE, exception_object->exception_class,
exception_object, context);
#endif
switch (personalityResult) {
case _URC_HANDLER_FOUND:
// found a catch clause or locals that need destructing in this frame
// stop search and remember stack pointer at the frame
handlerNotFound = false;
#ifndef __arm__
unw_get_reg(&cursor1, UNW_REG_SP, &sp);
exception_object->private_2 = (uintptr_t)sp;
#else
// p should have initialized barrier_cache. #7.3.5
#endif
_LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): "
"_URC_HANDLER_FOUND \n",
exception_object);
return _URC_NO_REASON;
case _URC_CONTINUE_UNWIND:
_LIBUNWIND_TRACE_UNWINDING(
"unwind_phase1(ex_ojb=%p): _URC_CONTINUE_UNWIND\n",
exception_object);
// continue unwinding
break;
#ifdef __arm__
// # 7.3.3
case _URC_FAILURE:
return _URC_FAILURE;
#endif
default:
// something went wrong
_LIBUNWIND_TRACE_UNWINDING(
"unwind_phase1(ex_ojb=%p): _URC_FATAL_PHASE1_ERROR\n",
exception_object);
return _URC_FATAL_PHASE1_ERROR;
}
}
}
return _URC_NO_REASON;
}
struct _Unwind_FunctionContext *__Unwind_SjLj_GetTopOfFunctionStack(void) {
_LIBUNWIND_TRACE_UNWINDING("__Unwind_SjLj_GetTopOfFunctionStack\n");
return (struct _Unwind_FunctionContext *) pthread_getspecific(PTHREAD_KEY_LIBCXX_SJLJ);
}
static _Unwind_Reason_Code
unwind_phase2(unw_context_t *uc, struct _Unwind_Exception *exception_object, bool resume) {
// See comment at the start of unwind_phase1 regarding VRS integrity.
unw_cursor_t cursor2;
unw_init_local(&cursor2, uc);
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p)\n", exception_object);
int frame_count = 0;
// Walk each frame until we reach where search phase said to stop.
while (true) {
// Ask libuwind to get next frame (skip over first which is
// _Unwind_RaiseException or _Unwind_Resume).
//
// Resume only ever makes sense for 1 frame.
_Unwind_State state =
resume ? _US_UNWIND_FRAME_RESUME : _US_UNWIND_FRAME_STARTING;
if (resume && frame_count == 1) {
// On a resume, first unwind the _Unwind_Resume() frame. The next frame
// is now the landing pad for the cleanup from a previous execution of
// phase2. To continue unwindingly correctly, replace VRS[15] with the
// IP of the frame that the previous run of phase2 installed the context
// for. After this, continue unwinding as if normal.
//
// See #7.4.6 for details.
unw_set_reg(&cursor2, UNW_REG_IP, exception_object->unwinder_cache.reserved2);
resume = false;
}
int stepResult = unw_step(&cursor2);
if (stepResult == 0) {
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): unw_step() reached "
"bottom => _URC_END_OF_STACK\n",
exception_object);
return _URC_END_OF_STACK;
} else if (stepResult < 0) {
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): unw_step failed => "
"_URC_FATAL_PHASE1_ERROR\n",
exception_object);
return _URC_FATAL_PHASE2_ERROR;
}
// Get info about this frame.
unw_word_t sp;
unw_proc_info_t frameInfo;
unw_get_reg(&cursor2, UNW_REG_SP, &sp);
if (unw_get_proc_info(&cursor2, &frameInfo) != UNW_ESUCCESS) {
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): unw_get_proc_info "
"failed => _URC_FATAL_PHASE1_ERROR\n",
exception_object);
return _URC_FATAL_PHASE2_ERROR;
}
// When tracing, print state information.
if (_LIBUNWIND_TRACING_UNWINDING) {
char functionName[512];
unw_word_t offset;
if ((unw_get_proc_name(&cursor2, functionName, 512, &offset) !=
UNW_ESUCCESS) || (frameInfo.start_ip + offset > frameInfo.end_ip))
strcpy(functionName, ".anonymous.");
_LIBUNWIND_TRACE_UNWINDING(
"unwind_phase2(ex_ojb=%p): start_ip=0x%llX, func=%s, sp=0x%llX, "
"lsda=0x%llX, personality=0x%llX\n",
exception_object, frameInfo.start_ip, functionName, sp,
frameInfo.lsda, frameInfo.handler);
}
// If there is a personality routine, tell it we are unwinding.
if (frameInfo.handler != 0) {
__personality_routine p =
(__personality_routine)(long)(frameInfo.handler);
struct _Unwind_Context *context = (struct _Unwind_Context *)(&cursor2);
#ifdef __arm__
exception_object->pr_cache.fnstart = frameInfo.start_ip;
exception_object->pr_cache.ehtp = (_Unwind_EHT_Header *)frameInfo.unwind_info;
exception_object->pr_cache.additional = frameInfo.flags;
_Unwind_Reason_Code personalityResult =
(*p)(state, exception_object, context);
#else
_Unwind_Action action = _UA_CLEANUP_PHASE;
if (sp == exception_object->private_2) {
// Tell personality this was the frame it marked in phase 1.
action = (_Unwind_Action)(_UA_CLEANUP_PHASE | _UA_HANDLER_FRAME);
}
_Unwind_Reason_Code personalityResult =
(*p)(1, action, exception_object->exception_class, exception_object,
context);
#endif
switch (personalityResult) {
case _URC_CONTINUE_UNWIND:
// Continue unwinding
_LIBUNWIND_TRACE_UNWINDING(
"unwind_phase2(ex_ojb=%p): _URC_CONTINUE_UNWIND\n",
exception_object);
#ifdef __arm__
if (sp == exception_object->barrier_cache.sp) {
#else
if (sp == exception_object->private_2) {
#endif
// Phase 1 said we would stop at this frame, but we did not...
_LIBUNWIND_ABORT("during phase1 personality function said it would "
"stop here, but now in phase2 it did not stop here");
}
break;
case _URC_INSTALL_CONTEXT:
_LIBUNWIND_TRACE_UNWINDING(
"unwind_phase2(ex_ojb=%p): _URC_INSTALL_CONTEXT\n",
exception_object);
// Personality routine says to transfer control to landing pad.
// We may get control back if landing pad calls _Unwind_Resume().
if (_LIBUNWIND_TRACING_UNWINDING) {
unw_word_t pc;
unw_get_reg(&cursor2, UNW_REG_IP, &pc);
unw_get_reg(&cursor2, UNW_REG_SP, &sp);
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): re-entering "
"user code with ip=0x%llX, sp=0x%llX\n",
exception_object, pc, sp);
}
#ifdef __arm__
// #7.4.1 says we need to preserve pc for when _Unwind_Resume is called
// back, to find this same frame.
unw_word_t pc;
unw_get_reg(&cursor2, UNW_REG_IP, &pc);
exception_object->unwinder_cache.reserved2 = (uint32_t)pc;
#endif
unw_resume(&cursor2);
// unw_resume() only returns if there was an error.
return _URC_FATAL_PHASE2_ERROR;
#ifdef __arm__
// # 7.4.3
case _URC_FAILURE:
abort();
#endif
default:
// Personality routine returned an unknown result code.
_LIBUNWIND_DEBUG_LOG("personality function returned unknown result %d",
personalityResult);
return _URC_FATAL_PHASE2_ERROR;
}
}
frame_count++;
}
// Clean up phase did not resume at the frame that the search phase
// said it would...
return _URC_FATAL_PHASE2_ERROR;
}
#ifndef __arm__
static _Unwind_Reason_Code
unwind_phase2_forced(unw_context_t *uc,
struct _Unwind_Exception *exception_object,
_Unwind_Stop_Fn stop, void *stop_parameter) {
unw_cursor_t cursor2;
unw_init_local(&cursor2, uc);
// Walk each frame until we reach where search phase said to stop
while (unw_step(&cursor2) > 0) {
// Update info about this frame.
unw_proc_info_t frameInfo;
if (unw_get_proc_info(&cursor2, &frameInfo) != UNW_ESUCCESS) {
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): unw_step "
"failed => _URC_END_OF_STACK\n",
exception_object);
return _URC_FATAL_PHASE2_ERROR;
}
// When tracing, print state information.
if (_LIBUNWIND_TRACING_UNWINDING) {
char functionName[512];
unw_word_t offset;
if ((unw_get_proc_name(&cursor2, functionName, 512, &offset) !=
UNW_ESUCCESS) || (frameInfo.start_ip + offset > frameInfo.end_ip))
strcpy(functionName, ".anonymous.");
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): "
"start_ip=0x%llX, func=%s, lsda=0x%llX, "
" personality=0x%llX\n",
exception_object, frameInfo.start_ip,
functionName, frameInfo.lsda,
frameInfo.handler);
}
// Call stop function at each frame.
_Unwind_Action action =
(_Unwind_Action)(_UA_FORCE_UNWIND | _UA_CLEANUP_PHASE);
_Unwind_Reason_Code stopResult =
(*stop)(1, action, exception_object->exception_class, exception_object,
(struct _Unwind_Context *)(&cursor2), stop_parameter);
_LIBUNWIND_TRACE_UNWINDING(
"unwind_phase2_forced(ex_ojb=%p): stop function returned %d\n",
exception_object, stopResult);
if (stopResult != _URC_NO_REASON) {
_LIBUNWIND_TRACE_UNWINDING(
"unwind_phase2_forced(ex_ojb=%p): stopped by stop function\n",
exception_object);
return _URC_FATAL_PHASE2_ERROR;
}
// If there is a personality routine, tell it we are unwinding.
if (frameInfo.handler != 0) {
__personality_routine p =
(__personality_routine)(long)(frameInfo.handler);
_LIBUNWIND_TRACE_UNWINDING(
"unwind_phase2_forced(ex_ojb=%p): calling personality function %p\n",
exception_object, p);
_Unwind_Reason_Code personalityResult =
(*p)(1, action, exception_object->exception_class, exception_object,
(struct _Unwind_Context *)(&cursor2));
switch (personalityResult) {
case _URC_CONTINUE_UNWIND:
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): "
"personality returned _URC_CONTINUE_UNWIND\n",
exception_object);
// Destructors called, continue unwinding
break;
case _URC_INSTALL_CONTEXT:
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): "
"personality returned _URC_INSTALL_CONTEXT\n",
exception_object);
// We may get control back if landing pad calls _Unwind_Resume().
unw_resume(&cursor2);
break;
default:
// Personality routine returned an unknown result code.
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): "
"personality returned %d, "
"_URC_FATAL_PHASE2_ERROR\n",
exception_object, personalityResult);
return _URC_FATAL_PHASE2_ERROR;
}
}
}
// Call stop function one last time and tell it we've reached the end
// of the stack.
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): calling stop "
"function with _UA_END_OF_STACK\n",
exception_object);
_Unwind_Action lastAction =
(_Unwind_Action)(_UA_FORCE_UNWIND | _UA_CLEANUP_PHASE | _UA_END_OF_STACK);
(*stop)(1, lastAction, exception_object->exception_class, exception_object,
(struct _Unwind_Context *)(&cursor2), stop_parameter);
// Clean up phase did not resume at the frame that the search phase said it
// would.
return _URC_FATAL_PHASE2_ERROR;
}
static _Unwind_Reason_Code
unwind_phase1(unw_context_t *uc, _Unwind_Exception *exception_object) {
unw_cursor_t cursor1;
unw_init_local(&cursor1, uc);
// Walk each frame looking for a place to stop.
for (bool handlerNotFound = true; handlerNotFound;) {
// Ask libuwind to get next frame (skip over first which is
// _Unwind_RaiseException).
int stepResult = unw_step(&cursor1);
if (stepResult == 0) {
_LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): unw_step() reached "
"bottom => _URC_END_OF_STACK\n",
exception_object);
return _URC_END_OF_STACK;
} else if (stepResult < 0) {
_LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): unw_step failed => "
"_URC_FATAL_PHASE1_ERROR\n",
exception_object);
return _URC_FATAL_PHASE1_ERROR;
}
// See if frame has code to run (has personality routine).
unw_proc_info_t frameInfo;
unw_word_t sp;
if (unw_get_proc_info(&cursor1, &frameInfo) != UNW_ESUCCESS) {
_LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): unw_get_proc_info "
"failed => _URC_FATAL_PHASE1_ERROR\n",
exception_object);
return _URC_FATAL_PHASE1_ERROR;
}
// When tracing, print state information.
if (_LIBUNWIND_TRACING_UNWINDING) {
char functionName[512];
unw_word_t offset;
if ((unw_get_proc_name(&cursor1, functionName, 512, &offset) !=
UNW_ESUCCESS) || (frameInfo.start_ip + offset > frameInfo.end_ip))
strcpy(functionName, ".anonymous.");
unw_word_t pc;
unw_get_reg(&cursor1, UNW_REG_IP, &pc);
_LIBUNWIND_TRACE_UNWINDING(
"unwind_phase1(ex_ojb=%p): pc=0x%llX, start_ip=0x%llX, func=%s, "
"lsda=0x%llX, personality=0x%llX\n",
exception_object, pc, frameInfo.start_ip, functionName,
frameInfo.lsda, frameInfo.handler);
}
// If there is a personality routine, ask it if it will want to stop at
// this frame.
if (frameInfo.handler != 0) {
__personality_routine p =
(__personality_routine)(long)(frameInfo.handler);
_LIBUNWIND_TRACE_UNWINDING(
"unwind_phase1(ex_ojb=%p): calling personality function %p\n",
exception_object, p);
_Unwind_Reason_Code personalityResult =
(*p)(1, _UA_SEARCH_PHASE, exception_object->exception_class,
exception_object, (struct _Unwind_Context *)(&cursor1));
switch (personalityResult) {
case _URC_HANDLER_FOUND:
// found a catch clause or locals that need destructing in this frame
// stop search and remember stack pointer at the frame
handlerNotFound = false;
unw_get_reg(&cursor1, UNW_REG_SP, &sp);
exception_object->private_2 = (uintptr_t)sp;
_LIBUNWIND_TRACE_UNWINDING("unwind_phase1(ex_ojb=%p): "
"_URC_HANDLER_FOUND \n",
exception_object);
return _URC_NO_REASON;
case _URC_CONTINUE_UNWIND:
_LIBUNWIND_TRACE_UNWINDING(
"unwind_phase1(ex_ojb=%p): _URC_CONTINUE_UNWIND\n",
exception_object);
// continue unwinding
break;
default:
// something went wrong
_LIBUNWIND_TRACE_UNWINDING(
"unwind_phase1(ex_ojb=%p): _URC_FATAL_PHASE1_ERROR\n",
exception_object);
return _URC_FATAL_PHASE1_ERROR;
}
}
}
return _URC_NO_REASON;
}
static _Unwind_Reason_Code
unwind_phase2_forced(unw_context_t *uc,
_Unwind_Exception *exception_object,
_Unwind_Stop_Fn stop, void *stop_parameter) {
unw_cursor_t cursor2;
unw_init_local(&cursor2, uc);
// Walk each frame until we reach where search phase said to stop
while (unw_step(&cursor2) > 0) {
// Update info about this frame.
unw_proc_info_t frameInfo;
if (unw_get_proc_info(&cursor2, &frameInfo) != UNW_ESUCCESS) {
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): unw_step "
"failed => _URC_END_OF_STACK\n",
exception_object);
return _URC_FATAL_PHASE2_ERROR;
}
// When tracing, print state information.
if (_LIBUNWIND_TRACING_UNWINDING) {
char functionName[512];
unw_word_t offset;
if ((unw_get_proc_name(&cursor2, functionName, 512, &offset) !=
UNW_ESUCCESS) || (frameInfo.start_ip + offset > frameInfo.end_ip))
strcpy(functionName, ".anonymous.");
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): "
"start_ip=0x%llX, func=%s, lsda=0x%llX, "
" personality=0x%llX\n",
exception_object, frameInfo.start_ip,
functionName, frameInfo.lsda,
frameInfo.handler);
}
// Call stop function at each frame.
_Unwind_Action action =
(_Unwind_Action)(_UA_FORCE_UNWIND | _UA_CLEANUP_PHASE);
_Unwind_Reason_Code stopResult =
(*stop)(1, action, exception_object->exception_class, exception_object,
(struct _Unwind_Context *)(&cursor2), stop_parameter);
_LIBUNWIND_TRACE_UNWINDING(
"unwind_phase2_forced(ex_ojb=%p): stop function returned %d\n",
exception_object, stopResult);
if (stopResult != _URC_NO_REASON) {
_LIBUNWIND_TRACE_UNWINDING(
"unwind_phase2_forced(ex_ojb=%p): stopped by stop function\n",
exception_object);
return _URC_FATAL_PHASE2_ERROR;
}
// If there is a personality routine, tell it we are unwinding.
if (frameInfo.handler != 0) {
__personality_routine p =
(__personality_routine)(long)(frameInfo.handler);
_LIBUNWIND_TRACE_UNWINDING(
"unwind_phase2_forced(ex_ojb=%p): calling personality function %p\n",
exception_object, p);
_Unwind_Reason_Code personalityResult =
(*p)(1, action, exception_object->exception_class, exception_object,
(struct _Unwind_Context *)(&cursor2));
switch (personalityResult) {
case _URC_CONTINUE_UNWIND:
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): "
"personality returned _URC_CONTINUE_UNWIND\n",
exception_object);
// Destructors called, continue unwinding
break;
case _URC_INSTALL_CONTEXT:
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): "
"personality returned _URC_INSTALL_CONTEXT\n",
exception_object);
// We may get control back if landing pad calls _Unwind_Resume().
unw_resume(&cursor2);
break;
default:
// Personality routine returned an unknown result code.
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): "
"personality returned %d, "
"_URC_FATAL_PHASE2_ERROR\n",
exception_object, personalityResult);
return _URC_FATAL_PHASE2_ERROR;
}
}
}
// Call stop function one last time and tell it we've reached the end
// of the stack.
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2_forced(ex_ojb=%p): calling stop "
"function with _UA_END_OF_STACK\n",
exception_object);
_Unwind_Action lastAction =
(_Unwind_Action)(_UA_FORCE_UNWIND | _UA_CLEANUP_PHASE | _UA_END_OF_STACK);
(*stop)(1, lastAction, exception_object->exception_class, exception_object,
(struct _Unwind_Context *)(&cursor2), stop_parameter);
// Clean up phase did not resume at the frame that the search phase said it
// would.
return _URC_FATAL_PHASE2_ERROR;
}
static _Unwind_Reason_Code
unwind_phase2(unw_context_t *uc, _Unwind_Exception *exception_object) {
unw_cursor_t cursor2;
unw_init_local(&cursor2, uc);
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p)\n", exception_object);
// Walk each frame until we reach where search phase said to stop.
while (true) {
// Ask libuwind to get next frame (skip over first which is
// _Unwind_RaiseException).
int stepResult = unw_step(&cursor2);
if (stepResult == 0) {
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): unw_step() reached "
"bottom => _URC_END_OF_STACK\n",
exception_object);
return _URC_END_OF_STACK;
} else if (stepResult < 0) {
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): unw_step failed => "
"_URC_FATAL_PHASE1_ERROR\n",
exception_object);
return _URC_FATAL_PHASE2_ERROR;
}
// Get info about this frame.
unw_word_t sp;
unw_proc_info_t frameInfo;
unw_get_reg(&cursor2, UNW_REG_SP, &sp);
if (unw_get_proc_info(&cursor2, &frameInfo) != UNW_ESUCCESS) {
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): unw_get_proc_info "
"failed => _URC_FATAL_PHASE1_ERROR\n",
exception_object);
return _URC_FATAL_PHASE2_ERROR;
}
// When tracing, print state information.
if (_LIBUNWIND_TRACING_UNWINDING) {
char functionName[512];
unw_word_t offset;
if ((unw_get_proc_name(&cursor2, functionName, 512, &offset) !=
UNW_ESUCCESS) || (frameInfo.start_ip + offset > frameInfo.end_ip))
strcpy(functionName, ".anonymous.");
_LIBUNWIND_TRACE_UNWINDING(
"unwind_phase2(ex_ojb=%p): start_ip=0x%llX, func=%s, sp=0x%llX, "
"lsda=0x%llX, personality=0x%llX\n",
exception_object, frameInfo.start_ip, functionName, sp,
frameInfo.lsda, frameInfo.handler);
}
// If there is a personality routine, tell it we are unwinding.
if (frameInfo.handler != 0) {
__personality_routine p =
(__personality_routine)(long)(frameInfo.handler);
_Unwind_Action action = _UA_CLEANUP_PHASE;
if (sp == exception_object->private_2) {
// Tell personality this was the frame it marked in phase 1.
action = (_Unwind_Action)(_UA_CLEANUP_PHASE | _UA_HANDLER_FRAME);
}
_Unwind_Reason_Code personalityResult =
(*p)(1, action, exception_object->exception_class, exception_object,
(struct _Unwind_Context *)(&cursor2));
switch (personalityResult) {
case _URC_CONTINUE_UNWIND:
// Continue unwinding
_LIBUNWIND_TRACE_UNWINDING(
"unwind_phase2(ex_ojb=%p): _URC_CONTINUE_UNWIND\n",
exception_object);
if (sp == exception_object->private_2) {
// Phase 1 said we would stop at this frame, but we did not...
_LIBUNWIND_ABORT("during phase1 personality function said it would "
"stop here, but now in phase2 it did not stop here");
}
break;
case _URC_INSTALL_CONTEXT:
_LIBUNWIND_TRACE_UNWINDING(
"unwind_phase2(ex_ojb=%p): _URC_INSTALL_CONTEXT\n",
exception_object);
// Personality routine says to transfer control to landing pad.
// We may get control back if landing pad calls _Unwind_Resume().
if (_LIBUNWIND_TRACING_UNWINDING) {
unw_word_t pc;
unw_get_reg(&cursor2, UNW_REG_IP, &pc);
unw_get_reg(&cursor2, UNW_REG_SP, &sp);
_LIBUNWIND_TRACE_UNWINDING("unwind_phase2(ex_ojb=%p): re-entering "
"user code with ip=0x%llX, sp=0x%llX\n",
exception_object, pc, sp);
}
unw_resume(&cursor2);
// unw_resume() only returns if there was an error.
return _URC_FATAL_PHASE2_ERROR;
default:
// Personality routine returned an unknown result code.
_LIBUNWIND_DEBUG_LOG("personality function returned unknown result %d",
personalityResult);
return _URC_FATAL_PHASE2_ERROR;
}
}
}
// Clean up phase did not resume at the frame that the search phase
// said it would...
return _URC_FATAL_PHASE2_ERROR;
}
/// Walk every frame and call trace function at each one. If trace function
/// returns anything other than _URC_NO_REASON, then walk is terminated.
_LIBUNWIND_EXPORT _Unwind_Reason_Code
_Unwind_Backtrace(_Unwind_Trace_Fn callback, void *ref) {
unw_cursor_t cursor;
unw_context_t uc;
unw_getcontext(&uc);
unw_init_local(&cursor, &uc);
_LIBUNWIND_TRACE_API("_Unwind_Backtrace(callback=%p)\n", callback);
// walk each frame
while (true) {
_Unwind_Reason_Code result;
// ask libuwind to get next frame (skip over first frame which is
// _Unwind_Backtrace())
if (unw_step(&cursor) <= 0) {
_LIBUNWIND_TRACE_UNWINDING(" _backtrace: ended because cursor reached "
"bottom of stack, returning %d\n",
_URC_END_OF_STACK);
return _URC_END_OF_STACK;
}
#if LIBCXXABI_ARM_EHABI
// Get the information for this frame.
unw_proc_info_t frameInfo;
if (unw_get_proc_info(&cursor, &frameInfo) != UNW_ESUCCESS) {
return _URC_END_OF_STACK;
}
struct _Unwind_Context *context = (struct _Unwind_Context *)&cursor;
const uint32_t* unwindInfo = (uint32_t *) frameInfo.unwind_info;
if ((*unwindInfo & 0x80000000) == 0) {
// 6.2: Generic Model
// EHT entry is a prel31 pointing to the PR, followed by data understood
// only by the personality routine. Since EHABI doesn't guarantee the
// location or availability of the unwind opcodes in the generic model,
// we have to call personality functions with (_US_VIRTUAL_UNWIND_FRAME |
// _US_FORCE_UNWIND) state.
// Create a mock exception object for force unwinding.
_Unwind_Exception ex;
ex.exception_class = 0x434C4E47554E5700; // CLNGUNW\0
ex.pr_cache.fnstart = frameInfo.start_ip;
ex.pr_cache.ehtp = (_Unwind_EHT_Header *) unwindInfo;
ex.pr_cache.additional= frameInfo.flags;
// Get and call the personality function to unwind the frame.
__personality_routine pr = (__personality_routine) readPrel31(unwindInfo);
if (pr(_US_VIRTUAL_UNWIND_FRAME | _US_FORCE_UNWIND, &ex, context) !=
_URC_CONTINUE_UNWIND) {
return _URC_END_OF_STACK;
}
} else {
size_t off, len;
unwindInfo = decode_eht_entry(unwindInfo, &off, &len);
if (unwindInfo == NULL) {
return _URC_FAILURE;
}
result = _Unwind_VRS_Interpret(context, unwindInfo, off, len);
if (result != _URC_CONTINUE_UNWIND) {
return _URC_END_OF_STACK;
}
}
#endif // LIBCXXABI_ARM_EHABI
// debugging
if (_LIBUNWIND_TRACING_UNWINDING) {
char functionName[512];
unw_proc_info_t frame;
unw_word_t offset;
unw_get_proc_name(&cursor, functionName, 512, &offset);
unw_get_proc_info(&cursor, &frame);
_LIBUNWIND_TRACE_UNWINDING(
" _backtrace: start_ip=0x%llX, func=%s, lsda=0x%llX, context=%p\n",
(long long)frame.start_ip, functionName,
(long long)frame.lsda, &cursor);
}
// call trace function with this frame
result = (*callback)((struct _Unwind_Context *)(&cursor), ref);
if (result != _URC_NO_REASON) {
_LIBUNWIND_TRACE_UNWINDING(" _backtrace: ended because callback "
"returned %d\n",
result);
return result;
}
}
}
