vm: fix tests failing, follow-up to #426

Deal with input and transitional VM states properly.
This commit is contained in:
Roman Khimov 2019-10-22 15:16:29 +03:00
parent 3cbb699eb7
commit a9a2a3c711

View file

@ -258,6 +258,12 @@ func (v *VM) Run() error {
return errors.New("no program loaded")
}
if v.state.HasFlag(faultState) {
// VM already ran something and failed, in general its state is
// undefined in this case so we can't run anything.
return errors.New("VM has failed")
}
// haltState (the default) or breakState are safe to continue.
v.state = noneState
for {
// check for breakpoint before executing the next instruction
@ -266,8 +272,13 @@ func (v *VM) Run() error {
v.state |= breakState
}
switch {
case v.state.HasFlag(faultState), v.state.HasFlag(haltState), v.state.HasFlag(breakState):
return errors.New("VM stopped")
case v.state.HasFlag(faultState):
// Should be caught and reported already by the v.Step(),
// but we're checking here anyway just in case.
return errors.New("VM has failed")
case v.state.HasFlag(haltState), v.state.HasFlag(breakState):
// Normal exit from this loop.
return nil
case v.state == noneState:
if err := v.Step(); err != nil {
return err