Update Lego

vendor/github.com/miekg/dns/duplicate_generate.go

@@ -0,0 +1,158 @@
+//+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/importer"
+	"go/types"
+	"log"
+	"os"
+)
+
+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.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
+}
+
+func main() {
+	// Import and type-check the package
+	pkg, err := importer.Default().Import("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 == "RFC3597" {
+			continue
+		}
+		if name == "OPT" || name == "ANY" || name == "IXFR" || name == "AXFR" {
+			continue
+		}
+
+		namedTypes = append(namedTypes, o.Name())
+	}
+
+	b := &bytes.Buffer{}
+	b.WriteString(packageHdr)
+
+	// Generate the giant switch that calls the correct function for each type.
+	fmt.Fprint(b, "// isDuplicateRdata calls the rdata specific functions\n")
+	fmt.Fprint(b, "func isDuplicateRdata(r1, r2 RR) bool {\n")
+	fmt.Fprint(b, "switch r1.Header().Rrtype {\n")
+
+	for _, name := range namedTypes {
+
+		o := scope.Lookup(name)
+		_, isEmbedded := getTypeStruct(o.Type(), scope)
+		if isEmbedded {
+			continue
+		}
+		fmt.Fprintf(b, "case Type%s:\nreturn isDuplicate%s(r1.(*%s), r2.(*%s))\n", name, name, name, name)
+	}
+	fmt.Fprintf(b, "}\nreturn false\n}\n")
+
+	// Generate the duplicate check for each type.
+	fmt.Fprint(b, "// isDuplicate() functions\n\n")
+	for _, name := range namedTypes {
+
+		o := scope.Lookup(name)
+		st, isEmbedded := getTypeStruct(o.Type(), scope)
+		if isEmbedded {
+			continue
+		}
+		fmt.Fprintf(b, "func isDuplicate%s(r1, r2 *%s) bool {\n", name, name)
+		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 || st.Tag(i) == `dns:"a"` || st.Tag(i) == `dns:"aaaa"` {
+				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 !isDulicateName(r1.%s[i], r2.%s[i]) {
+							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:"cdomain-name"`, `dns:"domain-name"`:
+				o2("if !isDulicateName(r1.%s, r2.%s) {\nreturn false\n}")
+			default:
+				o2("if r1.%s != r2.%s {\nreturn false\n}")
+			}
+		}
+		fmt.Fprintf(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)
+	}
+}