// Put file and line information on head of message.
		format = "%s:%d: " + format + "\n"
		args = append([]interface{}{p.lex.File(), p.lineNum}, args...)
	}
	fmt.Fprintf(p.errorWriter, format, args...)
	p.errorCount++
	if p.errorCount > 10 && !*flags.AllErrors {
		log.Fatal("too many errors")
	}
}

func (p *Parser) pos() src.XPos {
	return p.ctxt.PosTable.XPos(src.MakePos(p.lex.Base(), uint(p.lineNum), 0))
}