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 ) {
DEBUG_PRINT_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);
DEBUG_PRINT_UNWINDING("unwind_phase2_forced(ex_ojb=%p): stop function returned %d\n", exception_object, stopResult);
if ( stopResult != _URC_NO_REASON ) {
DEBUG_PRINT_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;
DEBUG_PRINT_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:
DEBUG_PRINT_UNWINDING("unwind_phase2_forced(ex_ojb=%p): personality returned _URC_CONTINUE_UNWIND\n", exception_object);
// destructors called, continue unwinding
break;
case _URC_INSTALL_CONTEXT:
DEBUG_PRINT_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
DEBUG_PRINT_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
DEBUG_PRINT_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;
}
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(struct _Unwind_Exception* exception_object)
{
DEBUG_PRINT_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 ) {
DEBUG_PRINT_UNWINDING("unwind_phase2s(ex_ojb=%p): function-context=%p\n", exception_object, c);
// check for no more frames
if ( c == NULL ) {
DEBUG_PRINT_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
DEBUG_PRINT_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...
ABORT("during phase1 personality function said it would stop here, but now if phase2 it did not stop here");
}
break;
case _URC_INSTALL_CONTEXT:
DEBUG_PRINT_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
DEBUG_MESSAGE("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;
}
/// Called at start of each function that catches exceptions
_LIBUNWIND_EXPORT void
_Unwind_SjLj_Register(struct _Unwind_FunctionContext *fc) {
fc->prev = __Unwind_SjLj_GetTopOfFunctionStack();
__Unwind_SjLj_SetTopOfFunctionStack(fc);
}