cmd/viewer: add codegen tool for Views

Signed-off-by: Maisem Ali <maisem@tailscale.com>

cmd/viewer/tests/tests.go

@@ -0,0 +1,48 @@
+// 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.
+
+// Package tests serves a list of tests for tailscale.com/cmd/viewer.
+package tests
+
+import (
+	"fmt"
+
+	"inet.af/netaddr"
+)
+
+//go:generate go run tailscale.com/cmd/viewer --type=StructWithPtrs,StructWithoutPtrs,Map,StructWithSlices
+
+type StructWithoutPtrs struct {
+	Int int
+	Pfx netaddr.IPPrefix
+}
+
+type Map struct {
+	M map[string]int
+}
+
+type StructWithPtrs struct {
+	Value *StructWithoutPtrs
+	Int   *int
+
+	NoCloneValue *StructWithoutPtrs `codegen:"noclone"`
+}
+
+func (v *StructWithPtrs) String() string { return fmt.Sprintf("%v", v.Int) }
+
+func (v *StructWithPtrs) Equal(v2 *StructWithPtrs) bool {
+	return v.Value == v2.Value
+}
+
+type StructWithSlices struct {
+	Values         []StructWithoutPtrs
+	ValuePointers  []*StructWithoutPtrs
+	StructPointers []*StructWithPtrs
+	Structs        []StructWithPtrs
+	Ints           []*int
+
+	Slice    []string
+	Prefixes []netaddr.IPPrefix
+	Data     []byte
+}

cmd/viewer/tests/tests_clone.go

@@ -0,0 +1,120 @@
+// 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.
+
+package tests
+
+import (
+	"inet.af/netaddr"
+)
+
+// Clone makes a deep copy of StructWithPtrs.
+// The result aliases no memory with the original.
+func (src *StructWithPtrs) Clone() *StructWithPtrs {
+	if src == nil {
+		return nil
+	}
+	dst := new(StructWithPtrs)
+	*dst = *src
+	if dst.Value != nil {
+		dst.Value = new(StructWithoutPtrs)
+		*dst.Value = *src.Value
+	}
+	if dst.Int != nil {
+		dst.Int = new(int)
+		*dst.Int = *src.Int
+	}
+	return dst
+}
+
+// A compilation failure here means this code must be regenerated, with the command at the top of this file.
+var _StructWithPtrsCloneNeedsRegeneration = StructWithPtrs(struct {
+	Value        *StructWithoutPtrs
+	Int          *int
+	NoCloneValue *StructWithoutPtrs
+}{})
+
+// Clone makes a deep copy of StructWithoutPtrs.
+// The result aliases no memory with the original.
+func (src *StructWithoutPtrs) Clone() *StructWithoutPtrs {
+	if src == nil {
+		return nil
+	}
+	dst := new(StructWithoutPtrs)
+	*dst = *src
+	return dst
+}
+
+// A compilation failure here means this code must be regenerated, with the command at the top of this file.
+var _StructWithoutPtrsCloneNeedsRegeneration = StructWithoutPtrs(struct {
+	Int int
+	Pfx netaddr.IPPrefix
+}{})
+
+// Clone makes a deep copy of Map.
+// The result aliases no memory with the original.
+func (src *Map) Clone() *Map {
+	if src == nil {
+		return nil
+	}
+	dst := new(Map)
+	*dst = *src
+	if dst.M != nil {
+		dst.M = map[string]int{}
+		for k, v := range src.M {
+			dst.M[k] = v
+		}
+	}
+	return dst
+}
+
+// A compilation failure here means this code must be regenerated, with the command at the top of this file.
+var _MapCloneNeedsRegeneration = Map(struct {
+	M map[string]int
+}{})
+
+// Clone makes a deep copy of StructWithSlices.
+// The result aliases no memory with the original.
+func (src *StructWithSlices) Clone() *StructWithSlices {
+	if src == nil {
+		return nil
+	}
+	dst := new(StructWithSlices)
+	*dst = *src
+	dst.Values = append(src.Values[:0:0], src.Values...)
+	dst.ValuePointers = make([]*StructWithoutPtrs, len(src.ValuePointers))
+	for i := range dst.ValuePointers {
+		dst.ValuePointers[i] = src.ValuePointers[i].Clone()
+	}
+	dst.StructPointers = make([]*StructWithPtrs, len(src.StructPointers))
+	for i := range dst.StructPointers {
+		dst.StructPointers[i] = src.StructPointers[i].Clone()
+	}
+	dst.Structs = make([]StructWithPtrs, len(src.Structs))
+	for i := range dst.Structs {
+		dst.Structs[i] = *src.Structs[i].Clone()
+	}
+	dst.Ints = make([]*int, len(src.Ints))
+	for i := range dst.Ints {
+		x := *src.Ints[i]
+		dst.Ints[i] = &x
+	}
+	dst.Slice = append(src.Slice[:0:0], src.Slice...)
+	dst.Prefixes = append(src.Prefixes[:0:0], src.Prefixes...)
+	dst.Data = append(src.Data[:0:0], src.Data...)
+	return dst
+}
+
+// A compilation failure here means this code must be regenerated, with the command at the top of this file.
+var _StructWithSlicesCloneNeedsRegeneration = StructWithSlices(struct {
+	Values         []StructWithoutPtrs
+	ValuePointers  []*StructWithoutPtrs
+	StructPointers []*StructWithPtrs
+	Structs        []StructWithPtrs
+	Ints           []*int
+	Slice          []string
+	Prefixes       []netaddr.IPPrefix
+	Data           []byte
+}{})

cmd/viewer/tests/tests_view.go

@@ -0,0 +1,268 @@
+// 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/cmd/viewer; DO NOT EDIT.
+
+package tests
+
+import (
+	"encoding/json"
+	"errors"
+
+	"go4.org/mem"
+	"inet.af/netaddr"
+	"tailscale.com/types/views"
+)
+
+//go:generate go run tailscale.com/cmd/cloner  -clonefunc=false -type=StructWithPtrs,StructWithoutPtrs,Map,StructWithSlices
+
+// View returns a readonly view of StructWithPtrs.
+func (p *StructWithPtrs) View() StructWithPtrsView {
+	return StructWithPtrsView{ж: p}
+}
+
+// StructWithPtrsView provides a read-only view over StructWithPtrs.
+//
+// Its methods should only be called if `Valid()` returns true.
+type StructWithPtrsView struct {
+	// ж is the underlying mutable value, named with a hard-to-type
+	// character that looks pointy like a pointer.
+	// It is named distinctively to make you think of how dangerous it is to escape
+	// to callers. You must not let callers be able to mutate it.
+	ж *StructWithPtrs
+}
+
+// Valid reports whether underlying value is non-nil.
+func (v StructWithPtrsView) Valid() bool { return v.ж != nil }
+
+// AsStruct returns a clone of the underlying value which aliases no memory with
+// the original.
+func (v StructWithPtrsView) AsStruct() *StructWithPtrs {
+	if v.ж == nil {
+		return nil
+	}
+	return v.ж.Clone()
+}
+
+func (v StructWithPtrsView) MarshalJSON() ([]byte, error) { return json.Marshal(v.ж) }
+
+func (v *StructWithPtrsView) UnmarshalJSON(b []byte) error {
+	if v.ж != nil {
+		return errors.New("already initialized")
+	}
+	if len(b) == 0 {
+		return nil
+	}
+	var x StructWithPtrs
+	if err := json.Unmarshal(b, &x); err != nil {
+		return err
+	}
+	v.ж = &x
+	return nil
+}
+
+func (v StructWithPtrsView) Value() *StructWithoutPtrs {
+	if v.ж.Value == nil {
+		return nil
+	}
+	x := *v.ж.Value
+	return &x
+}
+
+func (v StructWithPtrsView) Int() *int {
+	if v.ж.Int == nil {
+		return nil
+	}
+	x := *v.ж.Int
+	return &x
+}
+
+func (v StructWithPtrsView) NoCloneValue() *StructWithoutPtrs { return v.ж.NoCloneValue }
+func (v StructWithPtrsView) String() string                   { return v.ж.String() }
+func (v StructWithPtrsView) Equal(v2 StructWithPtrsView) bool { return v.ж.Equal(v2.ж) }
+
+// A compilation failure here means this code must be regenerated, with the command at the top of this file.
+var _StructWithPtrsViewNeedsRegeneration = StructWithPtrs(struct {
+	Value        *StructWithoutPtrs
+	Int          *int
+	NoCloneValue *StructWithoutPtrs
+}{})
+
+// View returns a readonly view of StructWithoutPtrs.
+func (p *StructWithoutPtrs) View() StructWithoutPtrsView {
+	return StructWithoutPtrsView{ж: p}
+}
+
+// StructWithoutPtrsView provides a read-only view over StructWithoutPtrs.
+//
+// Its methods should only be called if `Valid()` returns true.
+type StructWithoutPtrsView struct {
+	// ж is the underlying mutable value, named with a hard-to-type
+	// character that looks pointy like a pointer.
+	// It is named distinctively to make you think of how dangerous it is to escape
+	// to callers. You must not let callers be able to mutate it.
+	ж *StructWithoutPtrs
+}
+
+// Valid reports whether underlying value is non-nil.
+func (v StructWithoutPtrsView) Valid() bool { return v.ж != nil }
+
+// AsStruct returns a clone of the underlying value which aliases no memory with
+// the original.
+func (v StructWithoutPtrsView) AsStruct() *StructWithoutPtrs {
+	if v.ж == nil {
+		return nil
+	}
+	return v.ж.Clone()
+}
+
+func (v StructWithoutPtrsView) MarshalJSON() ([]byte, error) { return json.Marshal(v.ж) }
+
+func (v *StructWithoutPtrsView) UnmarshalJSON(b []byte) error {
+	if v.ж != nil {
+		return errors.New("already initialized")
+	}
+	if len(b) == 0 {
+		return nil
+	}
+	var x StructWithoutPtrs
+	if err := json.Unmarshal(b, &x); err != nil {
+		return err
+	}
+	v.ж = &x
+	return nil
+}
+
+func (v StructWithoutPtrsView) Int() int              { return v.ж.Int }
+func (v StructWithoutPtrsView) Pfx() netaddr.IPPrefix { return v.ж.Pfx }
+
+// A compilation failure here means this code must be regenerated, with the command at the top of this file.
+var _StructWithoutPtrsViewNeedsRegeneration = StructWithoutPtrs(struct {
+	Int int
+	Pfx netaddr.IPPrefix
+}{})
+
+// View returns a readonly view of Map.
+func (p *Map) View() MapView {
+	return MapView{ж: p}
+}
+
+// MapView provides a read-only view over Map.
+//
+// Its methods should only be called if `Valid()` returns true.
+type MapView struct {
+	// ж is the underlying mutable value, named with a hard-to-type
+	// character that looks pointy like a pointer.
+	// It is named distinctively to make you think of how dangerous it is to escape
+	// to callers. You must not let callers be able to mutate it.
+	ж *Map
+}
+
+// Valid reports whether underlying value is non-nil.
+func (v MapView) Valid() bool { return v.ж != nil }
+
+// AsStruct returns a clone of the underlying value which aliases no memory with
+// the original.
+func (v MapView) AsStruct() *Map {
+	if v.ж == nil {
+		return nil
+	}
+	return v.ж.Clone()
+}
+
+func (v MapView) MarshalJSON() ([]byte, error) { return json.Marshal(v.ж) }
+
+func (v *MapView) UnmarshalJSON(b []byte) error {
+	if v.ж != nil {
+		return errors.New("already initialized")
+	}
+	if len(b) == 0 {
+		return nil
+	}
+	var x Map
+	if err := json.Unmarshal(b, &x); err != nil {
+		return err
+	}
+	v.ж = &x
+	return nil
+}
+
+// A compilation failure here means this code must be regenerated, with the command at the top of this file.
+var _MapViewNeedsRegeneration = Map(struct {
+	M map[string]int
+}{})
+
+// View returns a readonly view of StructWithSlices.
+func (p *StructWithSlices) View() StructWithSlicesView {
+	return StructWithSlicesView{ж: p}
+}
+
+// StructWithSlicesView provides a read-only view over StructWithSlices.
+//
+// Its methods should only be called if `Valid()` returns true.
+type StructWithSlicesView struct {
+	// ж is the underlying mutable value, named with a hard-to-type
+	// character that looks pointy like a pointer.
+	// It is named distinctively to make you think of how dangerous it is to escape
+	// to callers. You must not let callers be able to mutate it.
+	ж *StructWithSlices
+}
+
+// Valid reports whether underlying value is non-nil.
+func (v StructWithSlicesView) Valid() bool { return v.ж != nil }
+
+// AsStruct returns a clone of the underlying value which aliases no memory with
+// the original.
+func (v StructWithSlicesView) AsStruct() *StructWithSlices {
+	if v.ж == nil {
+		return nil
+	}
+	return v.ж.Clone()
+}
+
+func (v StructWithSlicesView) MarshalJSON() ([]byte, error) { return json.Marshal(v.ж) }
+
+func (v *StructWithSlicesView) UnmarshalJSON(b []byte) error {
+	if v.ж != nil {
+		return errors.New("already initialized")
+	}
+	if len(b) == 0 {
+		return nil
+	}
+	var x StructWithSlices
+	if err := json.Unmarshal(b, &x); err != nil {
+		return err
+	}
+	v.ж = &x
+	return nil
+}
+
+func (v StructWithSlicesView) Values() views.Slice[StructWithoutPtrs] {
+	return views.SliceOf(v.ж.Values)
+}
+func (v StructWithSlicesView) ValuePointers() views.SliceView[*StructWithoutPtrs, StructWithoutPtrsView] {
+	return views.SliceOfViews[*StructWithoutPtrs, StructWithoutPtrsView](v.ж.ValuePointers)
+}
+func (v StructWithSlicesView) StructPointers() views.SliceView[*StructWithPtrs, StructWithPtrsView] {
+	return views.SliceOfViews[*StructWithPtrs, StructWithPtrsView](v.ж.StructPointers)
+}
+func (v StructWithSlicesView) Structs() StructWithPtrs    { panic("unsupported") }
+func (v StructWithSlicesView) Ints() *int                 { panic("unsupported") }
+func (v StructWithSlicesView) Slice() views.Slice[string] { return views.SliceOf(v.ж.Slice) }
+func (v StructWithSlicesView) Prefixes() views.IPPrefixSlice {
+	return views.IPPrefixSliceOf(v.ж.Prefixes)
+}
+func (v StructWithSlicesView) Data() mem.RO { return mem.B(v.ж.Data) }
+
+// A compilation failure here means this code must be regenerated, with the command at the top of this file.
+var _StructWithSlicesViewNeedsRegeneration = StructWithSlices(struct {
+	Values         []StructWithoutPtrs
+	ValuePointers  []*StructWithoutPtrs
+	StructPointers []*StructWithPtrs
+	Structs        []StructWithPtrs
+	Ints           []*int
+	Slice          []string
+	Prefixes       []netaddr.IPPrefix
+	Data           []byte
+}{})