public void PeekWriteArrayType(int n, TypeRef expType)
{
var type = PeekType(n);
var s = type.Style(RootEnv);
if (s is NullTypeStyle)
{
// No-op.
// If stack entry is generalized it must become an array type
}
else if (s is ArrayTypeStyle)
{
// If stack entry is generalized it must remain an array type
expType = expType.ToRunTimeType(RootEnv, false);
type = type.Arguments[0];
if (!expType.IsAssignableTo(RootEnv, type))
{
throw new InvalidOperationException("array element type is not assignable from expected type");
}
}
else
{
// Parameter types not allowed
throw new InvalidOperationException("stack entry is not an array type");
}
}
public void SetUpperBound(RootEnvironment rootEnv, TypeRef type, BoolRef changed)
{
var s = type.Style(rootEnv);
if (s is ValueTypeStyle || s is PointerTypeStyle || s is CodePointerTypeStyle)
{
// These types are only assignable to themselves, so no need to remember
// the upper bound, just check it
if (!Type.IsAssignableTo(rootEnv, type))
{
if (s is UnmanagedPointerTypeStyle)
{
throw new InvalidOperationException("unmanaged pointer");
}
else
{
throw new InvalidOperationException("stack entry cannot be generalized");
}
}
}
else
{
var upperBound = UpperBound == null ? type : UpperBound.Glb(rootEnv, type, changed);
if (!Type.IsAssignableTo(rootEnv, upperBound))
{
throw new InvalidOperationException("stack entry cannot be generalized");
}
if (!upperBound.IsEquivalentTo(rootEnv, rootEnv.Global.ObjectRef))
{
if (UpperBound == null)
{
changed.Set();
}
UpperBound = upperBound;
}
}
}
