cmd/cloner,util/codegen: refactor cloner internals to allow reuse

Also run go generate again for Copyright updates.

Signed-off-by: Maisem Ali <maisem@tailscale.com>
bradfitz/dot
Maisem Ali 2 years ago committed by Maisem Ali
parent 025867fd07
commit e409e59a54

@ -22,13 +22,11 @@ import (
"os"
"strings"
"golang.org/x/tools/go/packages"
"tailscale.com/util/codegen"
)
var (
flagTypes = flag.String("type", "", "comma-separated list of types; required")
flagOutput = flag.String("output", "", "output file; required")
flagBuildTags = flag.String("tags", "", "compiler build tags to apply")
flagCloneFunc = flag.Bool("clonefunc", false, "add a top-level Clone func")
)
@ -43,30 +41,18 @@ func main() {
}
typeNames := strings.Split(*flagTypes, ",")
cfg := &packages.Config{
Mode: packages.NeedTypes | packages.NeedTypesInfo | packages.NeedSyntax | packages.NeedName,
Tests: false,
}
if *flagBuildTags != "" {
cfg.BuildFlags = []string{"-tags=" + *flagBuildTags}
}
pkgs, err := packages.Load(cfg, ".")
pkg, namedTypes, err := codegen.LoadTypes(*flagBuildTags, ".")
if err != nil {
log.Fatal(err)
}
if len(pkgs) != 1 {
log.Fatalf("wrong number of packages: %d", len(pkgs))
}
pkg := pkgs[0]
it := codegen.NewImportTracker(pkg.Types)
buf := new(bytes.Buffer)
imports := make(map[string]struct{})
namedTypes := codegen.NamedTypes(pkg)
for _, typeName := range typeNames {
typ, ok := namedTypes[typeName]
if !ok {
log.Fatalf("could not find type %s", typeName)
}
gen(buf, imports, typ, pkg.Types)
gen(buf, it, typ)
}
w := func(format string, args ...any) {
@ -93,62 +79,13 @@ func main() {
w(" return false")
w("}")
}
contents := new(bytes.Buffer)
var flagArgs []string
if *flagTypes != "" {
flagArgs = append(flagArgs, "-type="+*flagTypes)
}
if *flagOutput != "" {
flagArgs = append(flagArgs, "-output="+*flagOutput)
}
if *flagBuildTags != "" {
flagArgs = append(flagArgs, "-tags="+*flagBuildTags)
}
if *flagCloneFunc {
flagArgs = append(flagArgs, "-clonefunc")
}
fmt.Fprintf(contents, header, strings.Join(flagArgs, " "), pkg.Name)
fmt.Fprintf(contents, "import (\n")
for s := range imports {
fmt.Fprintf(contents, "\t%q\n", s)
}
fmt.Fprintf(contents, ")\n\n")
contents.Write(buf.Bytes())
output := *flagOutput
if output == "" {
flag.Usage()
os.Exit(2)
}
if err := codegen.WriteFormatted(contents.Bytes(), output); err != nil {
cloneOutput := pkg.Name + "_clone.go"
if err := codegen.WritePackageFile("tailscale.com/cmd/cloner", pkg, cloneOutput, it, buf); err != nil {
log.Fatal(err)
}
}
const header = `// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Code generated by tailscale.com/cmd/cloner; DO NOT EDIT.
//` + `go:generate` + ` go run tailscale.com/cmd/cloner %s
package %s
`
func gen(buf *bytes.Buffer, imports map[string]struct{}, typ *types.Named, thisPkg *types.Package) {
pkgQual := func(pkg *types.Package) string {
if thisPkg == pkg {
return ""
}
imports[pkg.Path()] = struct{}{}
return pkg.Name()
}
importedName := func(t types.Type) string {
return types.TypeString(t, pkgQual)
}
func gen(buf *bytes.Buffer, it *codegen.ImportTracker, typ *types.Named) {
t, ok := typ.Underlying().(*types.Struct)
if !ok {
return
@ -169,11 +106,11 @@ func gen(buf *bytes.Buffer, imports map[string]struct{}, typ *types.Named, thisP
for i := 0; i < t.NumFields(); i++ {
fname := t.Field(i).Name()
ft := t.Field(i).Type()
if !codegen.ContainsPointers(ft) {
if !codegen.ContainsPointers(ft) || codegen.HasNoClone(t.Tag(i)) {
continue
}
if named, _ := ft.(*types.Named); named != nil {
if isViewType(ft) {
if codegen.IsViewType(ft) {
writef("dst.%s = src.%s", fname, fname)
continue
}
@ -185,7 +122,7 @@ func gen(buf *bytes.Buffer, imports map[string]struct{}, typ *types.Named, thisP
switch ft := ft.Underlying().(type) {
case *types.Slice:
if codegen.ContainsPointers(ft.Elem()) {
n := importedName(ft.Elem())
n := it.QualifiedName(ft.Elem())
writef("dst.%s = make([]%s, len(src.%s))", fname, n, fname)
writef("for i := range dst.%s {", fname)
if _, isPtr := ft.Elem().(*types.Pointer); isPtr {
@ -202,7 +139,7 @@ func gen(buf *bytes.Buffer, imports map[string]struct{}, typ *types.Named, thisP
writef("dst.%s = src.%s.Clone()", fname, fname)
continue
}
n := importedName(ft.Elem())
n := it.QualifiedName(ft.Elem())
writef("if dst.%s != nil {", fname)
writef("\tdst.%s = new(%s)", fname, n)
writef("\t*dst.%s = *src.%s", fname, fname)
@ -212,9 +149,9 @@ func gen(buf *bytes.Buffer, imports map[string]struct{}, typ *types.Named, thisP
writef("}")
case *types.Map:
writef("if dst.%s != nil {", fname)
writef("\tdst.%s = map[%s]%s{}", fname, importedName(ft.Key()), importedName(ft.Elem()))
writef("\tdst.%s = map[%s]%s{}", fname, it.QualifiedName(ft.Key()), it.QualifiedName(ft.Elem()))
if sliceType, isSlice := ft.Elem().(*types.Slice); isSlice {
n := importedName(sliceType.Elem())
n := it.QualifiedName(sliceType.Elem())
writef("\tfor k := range src.%s {", fname)
// use zero-length slice instead of nil to ensure
// the key is always copied.
@ -237,20 +174,10 @@ func gen(buf *bytes.Buffer, imports map[string]struct{}, typ *types.Named, thisP
writef("return dst")
fmt.Fprintf(buf, "}\n\n")
buf.Write(codegen.AssertStructUnchanged(t, thisPkg, name, "Clone", imports))
}
func isViewType(typ types.Type) bool {
t, ok := typ.Underlying().(*types.Struct)
if !ok {
return false
}
if t.NumFields() != 1 {
return false
}
return t.Field(0).Name() == "ж"
buf.Write(codegen.AssertStructUnchanged(t, name, "Clone", it))
}
// hasBasicUnderlying reports true when typ.Underlying() is a slice or a map.
func hasBasicUnderlying(typ types.Type) bool {
switch typ.Underlying().(type) {
case *types.Slice, *types.Map:

@ -1,9 +1,8 @@
// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
// Copyright (c) 2022 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Code generated by tailscale.com/cmd/cloner; DO NOT EDIT.
//go:generate go run tailscale.com/cmd/cloner -type=Prefs -output=prefs_clone.go
package ipn

@ -27,7 +27,7 @@ import (
"tailscale.com/util/dnsname"
)
//go:generate go run tailscale.com/cmd/cloner -type=Prefs -output=prefs_clone.go
//go:generate go run tailscale.com/cmd/cloner -type=Prefs
// DefaultControlURL is the URL base of the control plane
// ("coordination server") for use when no explicit one is configured.

@ -4,7 +4,7 @@
package tailcfg
//go:generate go run tailscale.com/cmd/cloner --type=User,Node,Hostinfo,NetInfo,Login,DNSConfig,RegisterResponse,DERPRegion,DERPMap,DERPNode --clonefunc=true --output=tailcfg_clone.go
//go:generate go run tailscale.com/cmd/cloner --type=User,Node,Hostinfo,NetInfo,Login,DNSConfig,RegisterResponse,DERPRegion,DERPMap,DERPNode --clonefunc
import (
"encoding/hex"

@ -1,9 +1,8 @@
// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
// Copyright (c) 2022 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Code generated by tailscale.com/cmd/cloner; DO NOT EDIT.
//go:generate go run tailscale.com/cmd/cloner -type=User,Node,Hostinfo,NetInfo,Login,DNSConfig,RegisterResponse,DERPRegion,DERPMap,DERPNode -output=tailcfg_clone.go -clonefunc
// Code generated by tailscale.com/util/codegen (cloner); DO NOT EDIT.
package tailcfg

@ -5,7 +5,7 @@
// Package dnstype defines types for working with DNS.
package dnstype
//go:generate go run tailscale.com/cmd/cloner --type=Resolver --clonefunc=true --output=dnstype_clone.go
//go:generate go run tailscale.com/cmd/cloner --type=Resolver --clonefunc=true
import "inet.af/netaddr"

@ -1,9 +1,8 @@
// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
// Copyright (c) 2022 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Code generated by tailscale.com/cmd/cloner; DO NOT EDIT.
//go:generate go run tailscale.com/cmd/cloner -type=Resolver -output=dnstype_clone.go -clonefunc
package dnstype

@ -12,7 +12,7 @@ import (
"tailscale.com/types/structs"
)
//go:generate go run tailscale.com/cmd/cloner -type=Persist -output=persist_clone.go
//go:generate go run tailscale.com/cmd/cloner -type=Persist
// Persist is the JSON type stored on disk on nodes to remember their
// settings between runs.

@ -1,9 +1,8 @@
// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
// Copyright (c) 2022 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Code generated by tailscale.com/cmd/cloner; DO NOT EDIT.
//go:generate go run tailscale.com/cmd/cloner -type=Persist -output=persist_clone.go
package persist

@ -11,13 +11,116 @@ import (
"go/ast"
"go/token"
"go/types"
"io"
"os"
"reflect"
"strings"
"time"
"golang.org/x/tools/go/packages"
"golang.org/x/tools/imports"
"tailscale.com/util/mak"
)
// WriteFormatted writes code to path.
// LoadTypes returns all named types in pkgName, keyed by their type name.
func LoadTypes(buildTags string, pkgName string) (*packages.Package, map[string]*types.Named, error) {
cfg := &packages.Config{
Mode: packages.NeedTypes | packages.NeedTypesInfo | packages.NeedSyntax | packages.NeedName,
Tests: false,
}
if buildTags != "" {
cfg.BuildFlags = []string{"-tags=" + buildTags}
}
pkgs, err := packages.Load(cfg, pkgName)
if err != nil {
return nil, nil, err
}
if len(pkgs) != 1 {
return nil, nil, fmt.Errorf("wrong number of packages: %d", len(pkgs))
}
pkg := pkgs[0]
return pkg, namedTypes(pkg), nil
}
// HasNoClone reports whether the provided tag has `codegen:noclone`.
func HasNoClone(structTag string) bool {
val := reflect.StructTag(structTag).Get("codegen")
for _, v := range strings.Split(val, ",") {
if v == "noclone" {
return true
}
}
return false
}
const header = `// Copyright (c) %d Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Code generated by %v; DO NOT EDIT.
package %s
`
func NewImportTracker(thisPkg *types.Package) *ImportTracker {
return &ImportTracker{
thisPkg: thisPkg,
}
}
// ImportTracker provides a mechanism to track and build import paths.
type ImportTracker struct {
thisPkg *types.Package
packages map[string]bool
}
func (it *ImportTracker) Import(pkg string) {
if pkg != "" && !it.packages[pkg] {
mak.Set(&it.packages, pkg, true)
}
}
func (it *ImportTracker) qualifier(pkg *types.Package) string {
if it.thisPkg == pkg {
return ""
}
it.Import(pkg.Path())
// TODO(maisem): handle conflicts?
return pkg.Name()
}
// QualifiedName returns the string representation of t in the package.
func (it *ImportTracker) QualifiedName(t types.Type) string {
return types.TypeString(t, it.qualifier)
}
// Write prints all the tracked imports in a single import block to w.
func (it *ImportTracker) Write(w io.Writer) {
fmt.Fprintf(w, "import (\n")
for s := range it.packages {
fmt.Fprintf(w, "\t%q\n", s)
}
fmt.Fprintf(w, ")\n\n")
}
func writeHeader(w io.Writer, tool, pkg string) {
fmt.Fprintf(w, header, time.Now().Year(), tool, pkg)
}
// WritePackageFile adds a file with the provided imports and contents to package.
// The tool param is used to identify the tool that generated package file.
func WritePackageFile(tool string, pkg *packages.Package, path string, it *ImportTracker, contents *bytes.Buffer) error {
buf := new(bytes.Buffer)
writeHeader(buf, tool, pkg.Name)
it.Write(buf)
if _, err := buf.Write(contents.Bytes()); err != nil {
return err
}
return writeFormatted(buf.Bytes(), path)
}
// writeFormatted writes code to path.
// It runs gofmt on it before writing;
// if gofmt fails, it writes code unchanged.
// Errors can include I/O errors and gofmt errors.
@ -28,7 +131,7 @@ import (
// It is nicer to work with it in a file than a terminal.
// It is also easier to interpret gofmt errors
// with an editor providing file and line numbers.
func WriteFormatted(code []byte, path string) error {
func writeFormatted(code []byte, path string) error {
out, fmterr := imports.Process(path, code, &imports.Options{
Comments: true,
TabIndent: true,
@ -50,8 +153,8 @@ func WriteFormatted(code []byte, path string) error {
return nil
}
// NamedTypes returns all named types in pkg, keyed by their type name.
func NamedTypes(pkg *packages.Package) map[string]*types.Named {
// namedTypes returns all named types in pkg, keyed by their type name.
func namedTypes(pkg *packages.Package) map[string]*types.Named {
nt := make(map[string]*types.Named)
for _, file := range pkg.Syntax {
for _, d := range file.Decls {
@ -64,7 +167,10 @@ func NamedTypes(pkg *packages.Package) map[string]*types.Named {
if !ok {
continue
}
typeNameObj := pkg.TypesInfo.Defs[spec.Name]
typeNameObj, ok := pkg.TypesInfo.Defs[spec.Name]
if !ok {
continue
}
typ, ok := typeNameObj.Type().(*types.Named)
if !ok {
continue
@ -82,7 +188,7 @@ func NamedTypes(pkg *packages.Package) map[string]*types.Named {
// ctx is a single-word context for this assertion, such as "Clone".
// If non-nil, AssertStructUnchanged will add elements to imports
// for each package path that the caller must import for the returned code to compile.
func AssertStructUnchanged(t *types.Struct, thisPkg *types.Package, tname, ctx string, imports map[string]struct{}) []byte {
func AssertStructUnchanged(t *types.Struct, tname, ctx string, it *ImportTracker) []byte {
buf := new(bytes.Buffer)
w := func(format string, args ...any) {
fmt.Fprintf(buf, format+"\n", args...)
@ -93,10 +199,10 @@ func AssertStructUnchanged(t *types.Struct, thisPkg *types.Package, tname, ctx s
for i := 0; i < t.NumFields(); i++ {
fname := t.Field(i).Name()
ft := t.Field(i).Type()
qname, imppath := importedName(ft, thisPkg)
if imppath != "" && imports != nil {
imports[imppath] = struct{}{}
if IsInvalid(ft) {
continue
}
qname := it.QualifiedName(ft)
w("\t%s %s", fname, qname)
}
@ -104,15 +210,11 @@ func AssertStructUnchanged(t *types.Struct, thisPkg *types.Package, tname, ctx s
return buf.Bytes()
}
func importedName(t types.Type, thisPkg *types.Package) (qualifiedName, importPkg string) {
qual := func(pkg *types.Package) string {
if thisPkg == pkg {
return ""
}
importPkg = pkg.Path()
return pkg.Name()
}
return types.TypeString(t, qual), importPkg
// IsInvalid reports whether the provided type is invalid. It is used to allow
// codegeneration to run even when the target files have build errors or are
// missing views.
func IsInvalid(t types.Type) bool {
return t.String() == "invalid type"
}
// ContainsPointers reports whether typ contains any pointers,
@ -149,3 +251,15 @@ func ContainsPointers(typ types.Type) bool {
}
return false
}
// IsViewType reports whether the provided typ is a View.
func IsViewType(typ types.Type) bool {
t, ok := typ.Underlying().(*types.Struct)
if !ok {
return false
}
if t.NumFields() != 1 {
return false
}
return t.Field(0).Name() == "ж"
}

@ -1,9 +1,8 @@
// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
// Copyright (c) 2022 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Code generated by tailscale.com/cmd/cloner; DO NOT EDIT.
//go:generate go run tailscale.com/cmd/cloner -type=Match -output=match_clone.go
package filter

@ -13,7 +13,7 @@ import (
"tailscale.com/types/ipproto"
)
//go:generate go run tailscale.com/cmd/cloner --type=Match --output=match_clone.go
//go:generate go run tailscale.com/cmd/cloner --type=Match
// PortRange is a range of TCP and UDP ports.
type PortRange struct {

@ -10,7 +10,7 @@ import (
"tailscale.com/types/key"
)
//go:generate go run tailscale.com/cmd/cloner -type=Config,Peer -output=clone.go
//go:generate go run tailscale.com/cmd/cloner -type=Config,Peer
// Config is a WireGuard configuration.
// It only supports the set of things Tailscale uses.

@ -1,9 +1,8 @@
// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
// Copyright (c) 2022 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Code generated by tailscale.com/cmd/cloner; DO NOT EDIT.
//go:generate go run tailscale.com/cmd/cloner -type=Config,Peer -output=clone.go
package wgcfg
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