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|
//+build ignore
package main
import (
"fmt"
"go/types"
"log"
"os"
"text/template"
"golang.org/x/tools/go/packages"
)
type Field struct {
Name string
Type string
}
var tpl = template.Must(template.New("").Parse(`package dns
// GENERATED FILE, DO NOT MODIFY
// See generate_dns_types.go in the repo root.
import (
"encoding/json"
"fmt"
"net"
"github.com/miekg/dns"
"code.crute.me/mcrute/go_ddns_manager/bind"
)
{{ range $name, $fields := . -}}
type {{ $name }} struct {
Name string
Ttl int
{{ range $fields -}}
{{ .Name }} {{ .Type }}
{{ end -}}
}
func (r *{{ $name }}) ToDNS(zone *bind.Zone) dns.RR {
return &dns.{{ $name }}{
Hdr: makeHeader(r.Name, zone, dns.Type{{ $name }}, r.Ttl),
{{ range $fields -}}
{{ .Name }}: r.{{ .Name }},
{{ end }}
}
}
func (r *{{ $name }}) FromDNS(rr dns.RR) error {
rt, ok := rr.(*dns.{{ $name }})
if !ok {
return fmt.Errorf("Invalid type %T for '{{ $name }}'", rr)
}
r.Name = rr.Header().Name
r.Ttl = int(rr.Header().Ttl)
{{ range $fields -}}
r.{{ .Name }} = rt.{{ .Name }}
{{ end }}
return nil
}
func (r *{{ $name }}) MarshalJSON() ([]byte, error) {
type Alias {{ $name }}
return json.Marshal(&struct {
Type string
*Alias
}{"{{ $name }}", (*Alias)(r)})
}
func (r *{{ $name }}) UnmarshalJSON(data []byte) error {
type Alias {{ $name }}
if err := json.Unmarshal(data, &struct{
Type string
*Alias
}{Alias: (*Alias)(r)}); err != nil {
return err
}
return nil
}
var _ RR = (*{{ $name }})(nil)
{{ end }}
func FromDNS(rr dns.RR) interface{} {
switch v := rr.(type) {
{{ range $name, $fields := . -}}
case *dns.{{ $name }}:
rv := &{{ $name }}{}
rv.FromDNS(v)
return rv
{{ end }}
}
return nil
}
`))
var disallowedTypes = map[string]bool{
"CDNSKEY": true,
"CDS": true,
"DLV": true,
"KEY": true,
"OPT": true,
"SIG": true,
"PrivateRR": true,
"RFC3597": true,
"ANY": true,
}
var allowedPackages = map[string]bool{
"net": true,
}
func main() {
conf := packages.Config{Mode: packages.NeedTypes | packages.NeedTypesInfo | packages.NeedDeps}
pkgs, err := packages.Load(&conf, "github.com/miekg/dns")
if err != nil {
panic(err)
}
scope := pkgs[0].Types.Scope()
localTypes := map[string][]Field{}
for _, name := range scope.Names() {
o := scope.Lookup(name)
if o == nil || !o.Exported() {
continue
}
// Only consider structs
st, ok := o.Type().Underlying().(*types.Struct)
if !ok {
continue
}
name := o.Name()
// Explicitly disallow some types that have complex embedded types
if _, skip := disallowedTypes[name]; skip {
continue
}
// There must be a type constant for this
if scope.Lookup(fmt.Sprintf("Type%s", name)) == nil {
continue
}
fields := []Field{}
for i := 0; i < st.NumFields(); i++ {
f := st.Field(i)
// Exclude header field
if f.Name() == "Hdr" {
continue
}
// Fail if there are complex types embedded
if tp, ok := f.Type().(*types.Named); ok {
if _, ok := allowedPackages[tp.Obj().Pkg().Path()]; !ok {
log.Fatalf("Invalid embedded complex type: %s", tp)
}
}
// Also fail if there are complex types embedded in a slice
if tp, ok := f.Type().(*types.Slice); ok {
if ut, ok := tp.Elem().(*types.Named); ok {
if _, ok := allowedPackages[ut.Obj().Pkg().Path()]; !ok {
log.Fatalf("Invalid embedded complex type: %s", tp)
}
}
}
fields = append(fields, Field{f.Name(), f.Type().String()})
}
localTypes[name] = fields
}
fp, err := os.Create("zzz_types.go")
if err != nil {
panic(err)
}
defer fp.Close()
tpl.Execute(fp, localTypes)
}
|
