Function RethrowGuestException

Source/Windows/ARM64EC/Module.cpp:528–559

}

static void RethrowGuestException(const EXCEPTION_RECORD& Rec, ARM64_NT_CONTEXT& Context) {
  const auto& Config = SignalDelegator->GetConfig();
  auto* Thread = GetCPUArea().ThreadState();
  auto& Fault = Thread->CurrentFrame->SynchronousFaultData;
  uint64_t GuestSp = Context.X[Config.SRAGPRMapping[static_cast<size_t>(FEXCore::X86State::REG_RSP)]];
  auto* Args = reinterpret_cast<KiUserExceptionDispatcherStackLayout*>(FEXCore::AlignDown(GuestSp, 64)) - 1;

  LogMan::Msg::DFmt("Reconstructing context");
  if (!IsDispatcherAddress(Context.Pc)) {
    ReconstructThreadState(Thread, Context);
  }
  Args->Context = StoreStateToPackedECContext(Thread, Context.Fpcr, Context.Fpsr);
  LogMan::Msg::DFmt("pc: {:X} rip: {:X}", Context.Pc, Args->Context.Pc);

  // X64 Windows always clears TF, DF and AF when handling an exception, restoring after.
  // Current ARM64EC windows can only restore NZCV+SS when returning from an exception and other flags are left untouched from the handler context.
  // TODO: Can extend wine to support this by mapping the remaining EFlags into reserved cpsr members.
  uint32_t EFlags = CTX->ReconstructCompactedEFLAGS(Thread, false, nullptr, 0);
  EFlags &= ~(1 << FEXCore::X86State::RFLAG_TF_RAW_LOC);
  CTX->SetFlagsFromCompactedEFLAGS(Thread, EFlags);

  Args->Rec = FEX::Windows::HandleGuestException(Fault, Rec, Args->Context.Pc, Args->Context.X8);
  if (Args->Rec.ExceptionCode == EXCEPTION_SINGLE_STEP) {
    Args->Context.Cpsr &= ~(1 << 21); // PSTATE.SS
  } else if (Args->Rec.ExceptionCode == EXCEPTION_BREAKPOINT) {
    // INT3 will set RIP to the instruction following it, undo this (any edge cases with multibyte instructions that trigger breakpoints are bugs present in Windows also)
    Args->Context.Pc -= 1;
  }

  Context.Sp = reinterpret_cast<uint64_t>(Args);
  Context.Pc = KiUserExceptionDispatcher;
}

class ECSyscallHandler : public FEXCore::HLE::SyscallHandler, public FEXCore::Allocator::FEXAllocOperators {
public: