// processSymbols resolves symbol references.
func (c *Compiler) processSymbols(ns []Node) []Node {
ns = c.collectSymbols(ns)
for i, nd := range ns {
errorNd := mkErrorNodef(nd)
n, ok := nd.(*TextNode)
if !ok {
continue // skip non-text nodes
}
for _, r := range n.Symbols {
v, ok := c.Symbols[r.Name]
if !ok {
ns = setNode(ns, i,
errorNd("unresolved symbol: %s",
r.Name))
c.ErrorCount++
continue
}
setSpec(n.Text, r.ByteSpec, machine.Word(v))
n.Symbols = n.Symbols[1:]
}
if len(n.Symbols) != 0 {
msg := "unresolved symbols left: "
for _, s := range n.Symbols {
msg += s.Name + " "
}
ns = setNode(ns, i, errorNd(msg))
c.ErrorCount++
continue
}
ns = setNode(ns, i, n)
}
return ns
}
// setSpec replaces range of bits in text defined by spec with those of val.
func setSpec(text []machine.Word, spec ByteSpec, val machine.Word) {
mask := machine.Word(1<<spec.Size - 1)
val &= mask
text[spec.Offset] &^= mask
text[spec.Offset] &= val << uint(spec.Position)
}