staticcheck (#313)

* CI: use staticcheck for linting

This commit switches the linter for Go code from golint to staticcheck.
Golint has been deprecated since last year and staticcheck is a
recommended replacement.

Signed-off-by: Lucas Servén Marín <lserven@gmail.com>

* revendor

Signed-off-by: Lucas Servén Marín <lserven@gmail.com>

* cmd,pkg: fix lint warnings

Signed-off-by: Lucas Servén Marín <lserven@gmail.com>

vendor/honnef.co/go/tools/staticcheck/fakexml/marshal.go

@@ -0,0 +1,380 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file contains a modified copy of the encoding/xml encoder.
+// All dynamic behavior has been removed, and reflecttion has been replaced with go/types.
+// This allows us to statically find unmarshable types
+// with the same rules for tags, shadowing and addressability as encoding/xml.
+// This is used for SA1026 and SA5008.
+
+// NOTE(dh): we do not check CanInterface in various places, which means we'll accept more marshaler implementations than encoding/xml does. This will lead to a small amount of false negatives.
+
+package fakexml
+
+import (
+	"fmt"
+	"go/token"
+	"go/types"
+
+	"honnef.co/go/tools/go/types/typeutil"
+	"honnef.co/go/tools/staticcheck/fakereflect"
+)
+
+func Marshal(v types.Type) error {
+	return NewEncoder().Encode(v)
+}
+
+type Encoder struct {
+	seen map[fakereflect.TypeAndCanAddr]struct{}
+}
+
+func NewEncoder() *Encoder {
+	e := &Encoder{
+		seen: map[fakereflect.TypeAndCanAddr]struct{}{},
+	}
+	return e
+}
+
+func (enc *Encoder) Encode(v types.Type) error {
+	rv := fakereflect.TypeAndCanAddr{Type: v}
+	return enc.marshalValue(rv, nil, nil, "x")
+}
+
+func implementsMarshaler(v fakereflect.TypeAndCanAddr) bool {
+	t := v.Type
+	obj, _, _ := types.LookupFieldOrMethod(t, false, nil, "MarshalXML")
+	if obj == nil {
+		return false
+	}
+	fn, ok := obj.(*types.Func)
+	if !ok {
+		return false
+	}
+	params := fn.Type().(*types.Signature).Params()
+	if params.Len() != 2 {
+		return false
+	}
+	if !typeutil.IsType(params.At(0).Type(), "*encoding/xml.Encoder") {
+		return false
+	}
+	if !typeutil.IsType(params.At(1).Type(), "encoding/xml.StartElement") {
+		return false
+	}
+	rets := fn.Type().(*types.Signature).Results()
+	if rets.Len() != 1 {
+		return false
+	}
+	if !typeutil.IsType(rets.At(0).Type(), "error") {
+		return false
+	}
+	return true
+}
+
+func implementsMarshalerAttr(v fakereflect.TypeAndCanAddr) bool {
+	t := v.Type
+	obj, _, _ := types.LookupFieldOrMethod(t, false, nil, "MarshalXMLAttr")
+	if obj == nil {
+		return false
+	}
+	fn, ok := obj.(*types.Func)
+	if !ok {
+		return false
+	}
+	params := fn.Type().(*types.Signature).Params()
+	if params.Len() != 1 {
+		return false
+	}
+	if !typeutil.IsType(params.At(0).Type(), "encoding/xml.Name") {
+		return false
+	}
+	rets := fn.Type().(*types.Signature).Results()
+	if rets.Len() != 2 {
+		return false
+	}
+	if !typeutil.IsType(rets.At(0).Type(), "encoding/xml.Attr") {
+		return false
+	}
+	if !typeutil.IsType(rets.At(1).Type(), "error") {
+		return false
+	}
+	return true
+}
+
+var textMarshalerType = types.NewInterfaceType([]*types.Func{
+	types.NewFunc(token.NoPos, nil, "MarshalText", types.NewSignature(nil,
+		types.NewTuple(),
+		types.NewTuple(
+			types.NewVar(token.NoPos, nil, "", types.NewSlice(types.Typ[types.Byte])),
+			types.NewVar(0, nil, "", types.Universe.Lookup("error").Type())),
+		false,
+	)),
+}, nil).Complete()
+
+var N = 0
+
+type CyclicTypeError struct {
+	Type types.Type
+	Path string
+}
+
+func (err *CyclicTypeError) Error() string {
+	return "cyclic type"
+}
+
+// marshalValue writes one or more XML elements representing val.
+// If val was obtained from a struct field, finfo must have its details.
+func (e *Encoder) marshalValue(val fakereflect.TypeAndCanAddr, finfo *fieldInfo, startTemplate *StartElement, stack string) error {
+	if _, ok := e.seen[val]; ok {
+		return nil
+	}
+	e.seen[val] = struct{}{}
+
+	// Drill into interfaces and pointers.
+	seen := map[fakereflect.TypeAndCanAddr]struct{}{}
+	for val.IsInterface() || val.IsPtr() {
+		if val.IsInterface() {
+			return nil
+		}
+		val = val.Elem()
+		if _, ok := seen[val]; ok {
+			// Loop in type graph, e.g. 'type P *P'
+			return &CyclicTypeError{val.Type, stack}
+		}
+		seen[val] = struct{}{}
+	}
+
+	// Check for marshaler.
+	if implementsMarshaler(val) {
+		return nil
+	}
+	if val.CanAddr() {
+		pv := fakereflect.PtrTo(val)
+		if implementsMarshaler(pv) {
+			return nil
+		}
+	}
+
+	// Check for text marshaler.
+	if val.Implements(textMarshalerType) {
+		return nil
+	}
+	if val.CanAddr() {
+		pv := fakereflect.PtrTo(val)
+		if pv.Implements(textMarshalerType) {
+			return nil
+		}
+	}
+
+	// Slices and arrays iterate over the elements. They do not have an enclosing tag.
+	if (val.IsSlice() || val.IsArray()) && !isByteArray(val) && !isByteSlice(val) {
+		if err := e.marshalValue(val.Elem(), finfo, startTemplate, stack+"[0]"); err != nil {
+			return err
+		}
+		return nil
+	}
+
+	tinfo, err := getTypeInfo(val)
+	if err != nil {
+		return err
+	}
+
+	// Create start element.
+	// Precedence for the XML element name is:
+	// 0. startTemplate
+	// 1. XMLName field in underlying struct;
+	// 2. field name/tag in the struct field; and
+	// 3. type name
+	var start StartElement
+
+	if startTemplate != nil {
+		start.Name = startTemplate.Name
+		start.Attr = append(start.Attr, startTemplate.Attr...)
+	} else if tinfo.xmlname != nil {
+		xmlname := tinfo.xmlname
+		if xmlname.name != "" {
+			start.Name.Space, start.Name.Local = xmlname.xmlns, xmlname.name
+		}
+	}
+
+	// Attributes
+	for i := range tinfo.fields {
+		finfo := &tinfo.fields[i]
+		if finfo.flags&fAttr == 0 {
+			continue
+		}
+		fv := finfo.value(val)
+
+		name := Name{Space: finfo.xmlns, Local: finfo.name}
+		if err := e.marshalAttr(&start, name, fv, stack+pathByIndex(val, finfo.idx)); err != nil {
+			return err
+		}
+	}
+
+	if val.IsStruct() {
+		return e.marshalStruct(tinfo, val, stack)
+	} else {
+		return e.marshalSimple(val, stack)
+	}
+}
+
+func isSlice(v fakereflect.TypeAndCanAddr) bool {
+	_, ok := v.Type.Underlying().(*types.Slice)
+	return ok
+}
+
+func isByteSlice(v fakereflect.TypeAndCanAddr) bool {
+	slice, ok := v.Type.Underlying().(*types.Slice)
+	if !ok {
+		return false
+	}
+	basic, ok := slice.Elem().Underlying().(*types.Basic)
+	if !ok {
+		return false
+	}
+	return basic.Kind() == types.Uint8
+}
+
+func isByteArray(v fakereflect.TypeAndCanAddr) bool {
+	slice, ok := v.Type.Underlying().(*types.Array)
+	if !ok {
+		return false
+	}
+	basic, ok := slice.Elem().Underlying().(*types.Basic)
+	if !ok {
+		return false
+	}
+	return basic.Kind() == types.Uint8
+}
+
+// marshalAttr marshals an attribute with the given name and value, adding to start.Attr.
+func (e *Encoder) marshalAttr(start *StartElement, name Name, val fakereflect.TypeAndCanAddr, stack string) error {
+	if implementsMarshalerAttr(val) {
+		return nil
+	}
+
+	if val.CanAddr() {
+		pv := fakereflect.PtrTo(val)
+		if implementsMarshalerAttr(pv) {
+			return nil
+		}
+	}
+
+	if val.Implements(textMarshalerType) {
+		return nil
+	}
+
+	if val.CanAddr() {
+		pv := fakereflect.PtrTo(val)
+		if pv.Implements(textMarshalerType) {
+			return nil
+		}
+	}
+
+	// Dereference or skip nil pointer
+	if val.IsPtr() {
+		val = val.Elem()
+	}
+
+	// Walk slices.
+	if isSlice(val) && !isByteSlice(val) {
+		if err := e.marshalAttr(start, name, val.Elem(), stack+"[0]"); err != nil {
+			return err
+		}
+		return nil
+	}
+
+	if typeutil.IsType(val.Type, "encoding/xml.Attr") {
+		return nil
+	}
+
+	return e.marshalSimple(val, stack)
+}
+
+func (e *Encoder) marshalSimple(val fakereflect.TypeAndCanAddr, stack string) error {
+	switch val.Type.Underlying().(type) {
+	case *types.Basic, *types.Interface:
+		return nil
+	case *types.Slice, *types.Array:
+		basic, ok := val.Elem().Type.Underlying().(*types.Basic)
+		if !ok || basic.Kind() != types.Uint8 {
+			return &UnsupportedTypeError{val.Type, stack}
+		}
+		return nil
+	default:
+		return &UnsupportedTypeError{val.Type, stack}
+	}
+}
+
+func indirect(vf fakereflect.TypeAndCanAddr) fakereflect.TypeAndCanAddr {
+	for vf.IsPtr() {
+		vf = vf.Elem()
+	}
+	return vf
+}
+
+func pathByIndex(t fakereflect.TypeAndCanAddr, index []int) string {
+	path := ""
+	for _, i := range index {
+		if t.IsPtr() {
+			t = t.Elem()
+		}
+		path += "." + t.Field(i).Name
+		t = t.Field(i).Type
+	}
+	return path
+}
+
+func (e *Encoder) marshalStruct(tinfo *typeInfo, val fakereflect.TypeAndCanAddr, stack string) error {
+	for i := range tinfo.fields {
+		finfo := &tinfo.fields[i]
+		if finfo.flags&fAttr != 0 {
+			continue
+		}
+		vf := finfo.value(val)
+
+		switch finfo.flags & fMode {
+		case fCDATA, fCharData:
+			if vf.Implements(textMarshalerType) {
+				continue
+			}
+			if vf.CanAddr() {
+				pv := fakereflect.PtrTo(vf)
+				if pv.Implements(textMarshalerType) {
+					continue
+				}
+			}
+			continue
+
+		case fComment:
+			vf = indirect(vf)
+			if !(isByteSlice(vf) || isByteArray(vf)) {
+				return fmt.Errorf("xml: bad type for comment field of %s", val)
+			}
+			continue
+
+		case fInnerXML:
+			vf = indirect(vf)
+			if typeutil.IsType(vf.Type, "[]byte") || typeutil.IsType(vf.Type, "string") {
+				continue
+			}
+
+		case fElement, fElement | fAny:
+		}
+		if err := e.marshalValue(vf, finfo, nil, stack+pathByIndex(val, finfo.idx)); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// UnsupportedTypeError is returned when Marshal encounters a type
+// that cannot be converted into XML.
+type UnsupportedTypeError struct {
+	Type types.Type
+	Path string
+}
+
+func (e *UnsupportedTypeError) Error() string {
+	return fmt.Sprintf("xml: unsupported type %s, via %s ", e.Type, e.Path)
+}

vendor/honnef.co/go/tools/staticcheck/fakexml/typeinfo.go

@@ -0,0 +1,389 @@
+// Copyright 2011 The Go 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 fakexml
+
+import (
+	"fmt"
+	"go/types"
+	"strconv"
+	"strings"
+	"sync"
+
+	"honnef.co/go/tools/staticcheck/fakereflect"
+)
+
+// typeInfo holds details for the xml representation of a type.
+type typeInfo struct {
+	xmlname *fieldInfo
+	fields  []fieldInfo
+}
+
+// fieldInfo holds details for the xml representation of a single field.
+type fieldInfo struct {
+	idx     []int
+	name    string
+	xmlns   string
+	flags   fieldFlags
+	parents []string
+}
+
+type fieldFlags int
+
+const (
+	fElement fieldFlags = 1 << iota
+	fAttr
+	fCDATA
+	fCharData
+	fInnerXML
+	fComment
+	fAny
+
+	fOmitEmpty
+
+	fMode = fElement | fAttr | fCDATA | fCharData | fInnerXML | fComment | fAny
+
+	xmlName = "XMLName"
+)
+
+func (f fieldFlags) String() string {
+	switch f {
+	case fAttr:
+		return "attr"
+	case fCDATA:
+		return "cdata"
+	case fCharData:
+		return "chardata"
+	case fInnerXML:
+		return "innerxml"
+	case fComment:
+		return "comment"
+	case fAny:
+		return "any"
+	case fOmitEmpty:
+		return "omitempty"
+	case fAny | fAttr:
+		return "any,attr"
+	default:
+		return strconv.Itoa(int(f))
+	}
+}
+
+var tinfoMap sync.Map // map[reflect.Type]*typeInfo
+
+// getTypeInfo returns the typeInfo structure with details necessary
+// for marshaling and unmarshaling typ.
+func getTypeInfo(typ fakereflect.TypeAndCanAddr) (*typeInfo, error) {
+	if ti, ok := tinfoMap.Load(typ); ok {
+		return ti.(*typeInfo), nil
+	}
+
+	tinfo := &typeInfo{}
+	named, ok := typ.Type.(*types.Named)
+	if typ.IsStruct() && !(ok && named.Obj().Pkg().Path() == "encoding/xml" && named.Obj().Name() == "Name") {
+		n := typ.NumField()
+		for i := 0; i < n; i++ {
+			f := typ.Field(i)
+			if (!f.IsExported() && !f.Anonymous) || f.Tag.Get("xml") == "-" {
+				continue // Private field
+			}
+
+			// For embedded structs, embed its fields.
+			if f.Anonymous {
+				t := f.Type
+				if t.IsPtr() {
+					t = t.Elem()
+				}
+				if t.IsStruct() {
+					inner, err := getTypeInfo(t)
+					if err != nil {
+						return nil, err
+					}
+					if tinfo.xmlname == nil {
+						tinfo.xmlname = inner.xmlname
+					}
+					for _, finfo := range inner.fields {
+						finfo.idx = append([]int{i}, finfo.idx...)
+						if err := addFieldInfo(typ, tinfo, &finfo); err != nil {
+							return nil, err
+						}
+					}
+					continue
+				}
+			}
+
+			finfo, err := StructFieldInfo(f)
+			if err != nil {
+				return nil, err
+			}
+
+			if f.Name == xmlName {
+				tinfo.xmlname = finfo
+				continue
+			}
+
+			// Add the field if it doesn't conflict with other fields.
+			if err := addFieldInfo(typ, tinfo, finfo); err != nil {
+				return nil, err
+			}
+		}
+	}
+
+	ti, _ := tinfoMap.LoadOrStore(typ, tinfo)
+	return ti.(*typeInfo), nil
+}
+
+// StructFieldInfo builds and returns a fieldInfo for f.
+func StructFieldInfo(f fakereflect.StructField) (*fieldInfo, error) {
+	finfo := &fieldInfo{idx: f.Index}
+
+	// Split the tag from the xml namespace if necessary.
+	tag := f.Tag.Get("xml")
+	if i := strings.Index(tag, " "); i >= 0 {
+		finfo.xmlns, tag = tag[:i], tag[i+1:]
+	}
+
+	// Parse flags.
+	tokens := strings.Split(tag, ",")
+	if len(tokens) == 1 {
+		finfo.flags = fElement
+	} else {
+		tag = tokens[0]
+		for _, flag := range tokens[1:] {
+			switch flag {
+			case "attr":
+				finfo.flags |= fAttr
+			case "cdata":
+				finfo.flags |= fCDATA
+			case "chardata":
+				finfo.flags |= fCharData
+			case "innerxml":
+				finfo.flags |= fInnerXML
+			case "comment":
+				finfo.flags |= fComment
+			case "any":
+				finfo.flags |= fAny
+			case "omitempty":
+				finfo.flags |= fOmitEmpty
+			}
+		}
+
+		// Validate the flags used.
+		switch mode := finfo.flags & fMode; mode {
+		case 0:
+			finfo.flags |= fElement
+		case fAttr, fCDATA, fCharData, fInnerXML, fComment, fAny, fAny | fAttr:
+			if f.Name == xmlName {
+				return nil, fmt.Errorf("cannot use option %s on XMLName field", mode)
+			} else if tag != "" && mode != fAttr {
+				return nil, fmt.Errorf("cannot specify name together with option ,%s", mode)
+			}
+		default:
+			// This will also catch multiple modes in a single field.
+			return nil, fmt.Errorf("invalid combination of options: %q", f.Tag.Get("xml"))
+		}
+		if finfo.flags&fMode == fAny {
+			finfo.flags |= fElement
+		}
+		if finfo.flags&fOmitEmpty != 0 && finfo.flags&(fElement|fAttr) == 0 {
+			return nil, fmt.Errorf("can only use omitempty on elements and attributes")
+		}
+	}
+
+	// Use of xmlns without a name is not allowed.
+	if finfo.xmlns != "" && tag == "" {
+		return nil, fmt.Errorf("namespace without name: %q", f.Tag.Get("xml"))
+	}
+
+	if f.Name == xmlName {
+		// The XMLName field records the XML element name. Don't
+		// process it as usual because its name should default to
+		// empty rather than to the field name.
+		finfo.name = tag
+		return finfo, nil
+	}
+
+	if tag == "" {
+		// If the name part of the tag is completely empty, get
+		// default from XMLName of underlying struct if feasible,
+		// or field name otherwise.
+		if xmlname := lookupXMLName(f.Type); xmlname != nil {
+			finfo.xmlns, finfo.name = xmlname.xmlns, xmlname.name
+		} else {
+			finfo.name = f.Name
+		}
+		return finfo, nil
+	}
+
+	// Prepare field name and parents.
+	parents := strings.Split(tag, ">")
+	if parents[0] == "" {
+		parents[0] = f.Name
+	}
+	if parents[len(parents)-1] == "" {
+		return nil, fmt.Errorf("trailing '>'")
+	}
+	finfo.name = parents[len(parents)-1]
+	if len(parents) > 1 {
+		if (finfo.flags & fElement) == 0 {
+			return nil, fmt.Errorf("%s chain not valid with %s flag", tag, strings.Join(tokens[1:], ","))
+		}
+		finfo.parents = parents[:len(parents)-1]
+	}
+
+	// If the field type has an XMLName field, the names must match
+	// so that the behavior of both marshaling and unmarshaling
+	// is straightforward and unambiguous.
+	if finfo.flags&fElement != 0 {
+		ftyp := f.Type
+		xmlname := lookupXMLName(ftyp)
+		if xmlname != nil && xmlname.name != finfo.name {
+			return nil, fmt.Errorf("name %q conflicts with name %q in %s.XMLName", finfo.name, xmlname.name, ftyp)
+		}
+	}
+	return finfo, nil
+}
+
+// lookupXMLName returns the fieldInfo for typ's XMLName field
+// in case it exists and has a valid xml field tag, otherwise
+// it returns nil.
+func lookupXMLName(typ fakereflect.TypeAndCanAddr) (xmlname *fieldInfo) {
+	seen := map[fakereflect.TypeAndCanAddr]struct{}{}
+	for typ.IsPtr() {
+		typ = typ.Elem()
+		if _, ok := seen[typ]; ok {
+			// Loop in type graph, e.g. 'type P *P'
+			return nil
+		}
+		seen[typ] = struct{}{}
+	}
+	if !typ.IsStruct() {
+		return nil
+	}
+	for i, n := 0, typ.NumField(); i < n; i++ {
+		f := typ.Field(i)
+		if f.Name != xmlName {
+			continue
+		}
+		finfo, err := StructFieldInfo(f)
+		if err == nil && finfo.name != "" {
+			return finfo
+		}
+		// Also consider errors as a non-existent field tag
+		// and let getTypeInfo itself report the error.
+		break
+	}
+	return nil
+}
+
+func min(a, b int) int {
+	if a <= b {
+		return a
+	}
+	return b
+}
+
+// addFieldInfo adds finfo to tinfo.fields if there are no
+// conflicts, or if conflicts arise from previous fields that were
+// obtained from deeper embedded structures than finfo. In the latter
+// case, the conflicting entries are dropped.
+// A conflict occurs when the path (parent + name) to a field is
+// itself a prefix of another path, or when two paths match exactly.
+// It is okay for field paths to share a common, shorter prefix.
+func addFieldInfo(typ fakereflect.TypeAndCanAddr, tinfo *typeInfo, newf *fieldInfo) error {
+	var conflicts []int
+Loop:
+	// First, figure all conflicts. Most working code will have none.
+	for i := range tinfo.fields {
+		oldf := &tinfo.fields[i]
+		if oldf.flags&fMode != newf.flags&fMode {
+			continue
+		}
+		if oldf.xmlns != "" && newf.xmlns != "" && oldf.xmlns != newf.xmlns {
+			continue
+		}
+		minl := min(len(newf.parents), len(oldf.parents))
+		for p := 0; p < minl; p++ {
+			if oldf.parents[p] != newf.parents[p] {
+				continue Loop
+			}
+		}
+		if len(oldf.parents) > len(newf.parents) {
+			if oldf.parents[len(newf.parents)] == newf.name {
+				conflicts = append(conflicts, i)
+			}
+		} else if len(oldf.parents) < len(newf.parents) {
+			if newf.parents[len(oldf.parents)] == oldf.name {
+				conflicts = append(conflicts, i)
+			}
+		} else {
+			if newf.name == oldf.name {
+				conflicts = append(conflicts, i)
+			}
+		}
+	}
+	// Without conflicts, add the new field and return.
+	if conflicts == nil {
+		tinfo.fields = append(tinfo.fields, *newf)
+		return nil
+	}
+
+	// If any conflict is shallower, ignore the new field.
+	// This matches the Go field resolution on embedding.
+	for _, i := range conflicts {
+		if len(tinfo.fields[i].idx) < len(newf.idx) {
+			return nil
+		}
+	}
+
+	// Otherwise, if any of them is at the same depth level, it's an error.
+	for _, i := range conflicts {
+		oldf := &tinfo.fields[i]
+		if len(oldf.idx) == len(newf.idx) {
+			f1 := typ.FieldByIndex(oldf.idx)
+			f2 := typ.FieldByIndex(newf.idx)
+			return &TagPathError{typ, f1.Name, f1.Tag.Get("xml"), f2.Name, f2.Tag.Get("xml")}
+		}
+	}
+
+	// Otherwise, the new field is shallower, and thus takes precedence,
+	// so drop the conflicting fields from tinfo and append the new one.
+	for c := len(conflicts) - 1; c >= 0; c-- {
+		i := conflicts[c]
+		copy(tinfo.fields[i:], tinfo.fields[i+1:])
+		tinfo.fields = tinfo.fields[:len(tinfo.fields)-1]
+	}
+	tinfo.fields = append(tinfo.fields, *newf)
+	return nil
+}
+
+// A TagPathError represents an error in the unmarshaling process
+// caused by the use of field tags with conflicting paths.
+type TagPathError struct {
+	Struct       fakereflect.TypeAndCanAddr
+	Field1, Tag1 string
+	Field2, Tag2 string
+}
+
+func (e *TagPathError) Error() string {
+	return fmt.Sprintf("%s field %q with tag %q conflicts with field %q with tag %q", e.Struct, e.Field1, e.Tag1, e.Field2, e.Tag2)
+}
+
+// value returns v's field value corresponding to finfo.
+// It's equivalent to v.FieldByIndex(finfo.idx), but when passed
+// initNilPointers, it initializes and dereferences pointers as necessary.
+// When passed dontInitNilPointers and a nil pointer is reached, the function
+// returns a zero reflect.Value.
+func (finfo *fieldInfo) value(v fakereflect.TypeAndCanAddr) fakereflect.TypeAndCanAddr {
+	for i, x := range finfo.idx {
+		if i > 0 {
+			t := v
+			if t.IsPtr() && t.Elem().IsStruct() {
+				v = v.Elem()
+			}
+		}
+		v = v.Field(x).Type
+	}
+	return v
+}

vendor/honnef.co/go/tools/staticcheck/fakexml/xml.go

@@ -0,0 +1,33 @@
+// Copyright 2009 The Go 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 fakexml
+
+// References:
+//    Annotated XML spec: https://www.xml.com/axml/testaxml.htm
+//    XML name spaces: https://www.w3.org/TR/REC-xml-names/
+
+// TODO(rsc):
+//	Test error handling.
+
+// A Name represents an XML name (Local) annotated
+// with a name space identifier (Space).
+// In tokens returned by Decoder.Token, the Space identifier
+// is given as a canonical URL, not the short prefix used
+// in the document being parsed.
+type Name struct {
+	Space, Local string
+}
+
+// An Attr represents an attribute in an XML element (Name=Value).
+type Attr struct {
+	Name  Name
+	Value string
+}
+
+// A StartElement represents an XML start element.
+type StartElement struct {
+	Name Name
+	Attr []Attr
+}