// ident type checks an identifier.
func (c *checker) ident(x *operand, e *ast.Ident, silent bool) {
x.mode = invalid
x.expr = e
_, obj := c.scope.LookupParent(Ord, e.Name, scan.NoPos)
if obj == nil {
_, obj = c.scope.LookupParent(Fwd, e.Name, scan.NoPos)
}
if obj == nil {
if !silent {
c.errorf(e.Span().Start, "undeclared name: %s", e.Name)
}
return
}
c.recordUse(e, obj)
typ := obj.Type()
switch obj := obj.(type) {
case *Const:
if typ == Typ[Invalid] {
return
}
x.val = obj.val
x.mode = constant_
case *Var:
if typ == Typ[Invalid] {
return
}
array, isArray := typ.(*Array)
if isArray {
typ = NewPointer(array.Elem(), array)
}
x.mode = variable
case *Fwrd:
if typ == Typ[Invalid] {
return
}
x.mode = variable
case *Func:
if typ == Typ[Invalid] {
return
}
x.mode = value
default:
panic(fmt.Sprintf("unknown ident type: %T", obj))
}
x.typ = typ
}
// variable looks up a variable given its identifier.
func (c *compiler) variable(d *ast.Ident, m map[*ast.Ident]types.Object) (*types.Var, bool) {
pos := d.Span().Start
obj, found := m[d]
if !found {
c.errorf(pos, "no type information for %s", d.Name)
return nil, false
}
v, ok := obj.(*types.Var)
if !ok {
c.errorf(pos, "not a valid variable")
}
switch v.Type() {
case types.Typ[types.Short], types.Typ[types.Long],
types.Typ[types.Float], types.Typ[types.Double],
types.Typ[types.Bool], types.Typ[types.Complex]:
c.errorf(pos, "unsupported type %s for variable", v.Type())
}
return v, true
}