1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
|
//go:build ignore
// +build ignore
// types_generate.go is meant to run with go generate. It will use
// go/{importer,types} to track down all the RR struct types. Then for each type
// it will generate conversion tables (TypeToRR and TypeToString) and banal
// methods (len, Header, copy) based on the struct tags. The generated source is
// written to ztypes.go, and is meant to be checked into git.
package main
import (
"bytes"
"fmt"
"go/format"
"go/types"
"log"
"os"
"golang.org/x/tools/go/packages"
)
var packageHdr = `
// Code generated by "go run duplicate_generate.go"; DO NOT EDIT.
package dns
`
func getTypeStruct(t types.Type, scope *types.Scope) (*types.Struct, bool) {
st, ok := t.Underlying().(*types.Struct)
if !ok {
return nil, false
}
if st.NumFields() == 0 {
return nil, false
}
if st.Field(0).Type() == scope.Lookup("RR_Header").Type() {
return st, false
}
if st.Field(0).Anonymous() {
st, _ := getTypeStruct(st.Field(0).Type(), scope)
return st, true
}
return nil, false
}
// loadModule retrieves package description for a given module.
func loadModule(name string) (*types.Package, error) {
conf := packages.Config{Mode: packages.NeedTypes | packages.NeedTypesInfo}
pkgs, err := packages.Load(&conf, name)
if err != nil {
return nil, err
}
return pkgs[0].Types, nil
}
func main() {
// Import and type-check the package
pkg, err := loadModule("github.com/miekg/dns")
fatalIfErr(err)
scope := pkg.Scope()
// Collect actual types (*X)
var namedTypes []string
for _, name := range scope.Names() {
o := scope.Lookup(name)
if o == nil || !o.Exported() {
continue
}
if st, _ := getTypeStruct(o.Type(), scope); st == nil {
continue
}
if name == "PrivateRR" || name == "OPT" {
continue
}
namedTypes = append(namedTypes, o.Name())
}
b := &bytes.Buffer{}
b.WriteString(packageHdr)
// Generate the duplicate check for each type.
fmt.Fprint(b, "// isDuplicate() functions\n\n")
for _, name := range namedTypes {
o := scope.Lookup(name)
st, _ := getTypeStruct(o.Type(), scope)
fmt.Fprintf(b, "func (r1 *%s) isDuplicate(_r2 RR) bool {\n", name)
fmt.Fprintf(b, "r2, ok := _r2.(*%s)\n", name)
fmt.Fprint(b, "if !ok { return false }\n")
fmt.Fprint(b, "_ = r2\n")
for i := 1; i < st.NumFields(); i++ {
field := st.Field(i).Name()
o2 := func(s string) { fmt.Fprintf(b, s+"\n", field, field) }
o3 := func(s string) { fmt.Fprintf(b, s+"\n", field, field, field) }
// For some reason, a and aaaa don't pop up as *types.Slice here (mostly like because the are
// *indirectly* defined as a slice in the net package).
if _, ok := st.Field(i).Type().(*types.Slice); ok {
o2("if len(r1.%s) != len(r2.%s) {\nreturn false\n}")
if st.Tag(i) == `dns:"cdomain-name"` || st.Tag(i) == `dns:"domain-name"` {
o3(`for i := 0; i < len(r1.%s); i++ {
if !isDuplicateName(r1.%s[i], r2.%s[i]) {
return false
}
}`)
continue
}
if st.Tag(i) == `dns:"apl"` {
o3(`for i := 0; i < len(r1.%s); i++ {
if !r1.%s[i].equals(&r2.%s[i]) {
return false
}
}`)
continue
}
if st.Tag(i) == `dns:"pairs"` {
o2(`if !areSVCBPairArraysEqual(r1.%s, r2.%s) {
return false
}`)
continue
}
o3(`for i := 0; i < len(r1.%s); i++ {
if r1.%s[i] != r2.%s[i] {
return false
}
}`)
continue
}
switch st.Tag(i) {
case `dns:"-"`:
// ignored
case `dns:"a"`, `dns:"aaaa"`:
o2("if !r1.%s.Equal(r2.%s) {\nreturn false\n}")
case `dns:"cdomain-name"`, `dns:"domain-name"`:
o2("if !isDuplicateName(r1.%s, r2.%s) {\nreturn false\n}")
case `dns:"ipsechost"`, `dns:"amtrelayhost"`:
o2(`switch r1.GatewayType {
case IPSECGatewayIPv4, IPSECGatewayIPv6:
if !r1.GatewayAddr.Equal(r2.GatewayAddr) {
return false
}
case IPSECGatewayHost:
if !isDuplicateName(r1.%s, r2.%s) {
return false
}
}
`)
default:
o2("if r1.%s != r2.%s {\nreturn false\n}")
}
}
fmt.Fprint(b, "return true\n}\n\n")
}
// gofmt
res, err := format.Source(b.Bytes())
if err != nil {
b.WriteTo(os.Stderr)
log.Fatal(err)
}
// write result
f, err := os.Create("zduplicate.go")
fatalIfErr(err)
defer f.Close()
f.Write(res)
}
func fatalIfErr(err error) {
if err != nil {
log.Fatal(err)
}
}
|
