package toml import ( "encoding" "errors" "fmt" "io" "io/ioutil" "math" "reflect" "strings" "sync/atomic" "time" "github.com/pelletier/go-toml/v2/internal/ast" "github.com/pelletier/go-toml/v2/internal/danger" "github.com/pelletier/go-toml/v2/internal/tracker" ) // Unmarshal deserializes a TOML document into a Go value. // // It is a shortcut for Decoder.Decode() with the default options. func Unmarshal(data []byte, v interface{}) error { p := parser{} p.Reset(data) d := decoder{p: &p} return d.FromParser(v) } // Decoder reads and decode a TOML document from an input stream. type Decoder struct { // input r io.Reader // global settings strict bool } // NewDecoder creates a new Decoder that will read from r. func NewDecoder(r io.Reader) *Decoder { return &Decoder{r: r} } // DisallowUnknownFields causes the Decoder to return an error when the // destination is a struct and the input contains a key that does not match a // non-ignored field. // // In that case, the Decoder returns a StrictMissingError that can be used to // retrieve the individual errors as well as generate a human readable // description of the missing fields. func (d *Decoder) DisallowUnknownFields() *Decoder { d.strict = true return d } // Decode the whole content of r into v. // // By default, values in the document that don't exist in the target Go value // are ignored. See Decoder.DisallowUnknownFields() to change this behavior. // // When a TOML local date, time, or date-time is decoded into a time.Time, its // value is represented in time.Local timezone. Otherwise the approriate Local* // structure is used. For time values, precision up to the nanosecond is // supported by truncating extra digits. // // Empty tables decoded in an interface{} create an empty initialized // map[string]interface{}. // // Types implementing the encoding.TextUnmarshaler interface are decoded from a // TOML string. // // When decoding a number, go-toml will return an error if the number is out of // bounds for the target type (which includes negative numbers when decoding // into an unsigned int). // // If an error occurs while decoding the content of the document, this function // returns a toml.DecodeError, providing context about the issue. When using // strict mode and a field is missing, a `toml.StrictMissingError` is // returned. In any other case, this function returns a standard Go error. // // # Type mapping // // List of supported TOML types and their associated accepted Go types: // // String -> string // Integer -> uint*, int*, depending on size // Float -> float*, depending on size // Boolean -> bool // Offset Date-Time -> time.Time // Local Date-time -> LocalDateTime, time.Time // Local Date -> LocalDate, time.Time // Local Time -> LocalTime, time.Time // Array -> slice and array, depending on elements types // Table -> map and struct // Inline Table -> same as Table // Array of Tables -> same as Array and Table func (d *Decoder) Decode(v interface{}) error { b, err := ioutil.ReadAll(d.r) if err != nil { return fmt.Errorf("toml: %w", err) } p := parser{} p.Reset(b) dec := decoder{ p: &p, strict: strict{ Enabled: d.strict, }, } return dec.FromParser(v) } type decoder struct { // Which parser instance in use for this decoding session. p *parser // Flag indicating that the current expression is stashed. // If set to true, calling nextExpr will not actually pull a new expression // but turn off the flag instead. stashedExpr bool // Skip expressions until a table is found. This is set to true when a // table could not be created (missing field in map), so all KV expressions // need to be skipped. skipUntilTable bool // Tracks position in Go arrays. // This is used when decoding [[array tables]] into Go arrays. Given array // tables are separate TOML expression, we need to keep track of where we // are at in the Go array, as we can't just introspect its size. arrayIndexes map[reflect.Value]int // Tracks keys that have been seen, with which type. seen tracker.SeenTracker // Strict mode strict strict // Current context for the error. errorContext *errorContext } type errorContext struct { Struct reflect.Type Field []int } func (d *decoder) typeMismatchError(toml string, target reflect.Type) error { if d.errorContext != nil && d.errorContext.Struct != nil { ctx := d.errorContext f := ctx.Struct.FieldByIndex(ctx.Field) return fmt.Errorf("toml: cannot decode TOML %s into struct field %s.%s of type %s", toml, ctx.Struct, f.Name, f.Type) } return fmt.Errorf("toml: cannot decode TOML %s into a Go value of type %s", toml, target) } func (d *decoder) expr() *ast.Node { return d.p.Expression() } func (d *decoder) nextExpr() bool { if d.stashedExpr { d.stashedExpr = false return true } return d.p.NextExpression() } func (d *decoder) stashExpr() { d.stashedExpr = true } func (d *decoder) arrayIndex(shouldAppend bool, v reflect.Value) int { if d.arrayIndexes == nil { d.arrayIndexes = make(map[reflect.Value]int, 1) } idx, ok := d.arrayIndexes[v] if !ok { d.arrayIndexes[v] = 0 } else if shouldAppend { idx++ d.arrayIndexes[v] = idx } return idx } func (d *decoder) FromParser(v interface{}) error { r := reflect.ValueOf(v) if r.Kind() != reflect.Ptr { return fmt.Errorf("toml: decoding can only be performed into a pointer, not %s", r.Kind()) } if r.IsNil() { return fmt.Errorf("toml: decoding pointer target cannot be nil") } r = r.Elem() if r.Kind() == reflect.Interface && r.IsNil() { newMap := map[string]interface{}{} r.Set(reflect.ValueOf(newMap)) } err := d.fromParser(r) if err == nil { return d.strict.Error(d.p.data) } var e *decodeError if errors.As(err, &e) { return wrapDecodeError(d.p.data, e) } return err } func (d *decoder) fromParser(root reflect.Value) error { for d.nextExpr() { err := d.handleRootExpression(d.expr(), root) if err != nil { return err } } return d.p.Error() } /* Rules for the unmarshal code: - The stack is used to keep track of which values need to be set where. - handle* functions <=> switch on a given ast.Kind. - unmarshalX* functions need to unmarshal a node of kind X. - An "object" is either a struct or a map. */ func (d *decoder) handleRootExpression(expr *ast.Node, v reflect.Value) error { var x reflect.Value var err error if !(d.skipUntilTable && expr.Kind == ast.KeyValue) { err = d.seen.CheckExpression(expr) if err != nil { return err } } switch expr.Kind { case ast.KeyValue: if d.skipUntilTable { return nil } x, err = d.handleKeyValue(expr, v) case ast.Table: d.skipUntilTable = false d.strict.EnterTable(expr) x, err = d.handleTable(expr.Key(), v) case ast.ArrayTable: d.skipUntilTable = false d.strict.EnterArrayTable(expr) x, err = d.handleArrayTable(expr.Key(), v) default: panic(fmt.Errorf("parser should not permit expression of kind %s at document root", expr.Kind)) } if d.skipUntilTable { if expr.Kind == ast.Table || expr.Kind == ast.ArrayTable { d.strict.MissingTable(expr) } } else if err == nil && x.IsValid() { v.Set(x) } return err } func (d *decoder) handleArrayTable(key ast.Iterator, v reflect.Value) (reflect.Value, error) { if key.Next() { return d.handleArrayTablePart(key, v) } return d.handleKeyValues(v) } func (d *decoder) handleArrayTableCollectionLast(key ast.Iterator, v reflect.Value) (reflect.Value, error) { switch v.Kind() { case reflect.Interface: elem := v.Elem() if !elem.IsValid() { elem = reflect.New(sliceInterfaceType).Elem() elem.Set(reflect.MakeSlice(sliceInterfaceType, 0, 16)) } else if elem.Kind() == reflect.Slice { if elem.Type() != sliceInterfaceType { elem = reflect.New(sliceInterfaceType).Elem() elem.Set(reflect.MakeSlice(sliceInterfaceType, 0, 16)) } else if !elem.CanSet() { nelem := reflect.New(sliceInterfaceType).Elem() nelem.Set(reflect.MakeSlice(sliceInterfaceType, elem.Len(), elem.Cap())) reflect.Copy(nelem, elem) elem = nelem } } return d.handleArrayTableCollectionLast(key, elem) case reflect.Ptr: elem := v.Elem() if !elem.IsValid() { ptr := reflect.New(v.Type().Elem()) v.Set(ptr) elem = ptr.Elem() } elem, err := d.handleArrayTableCollectionLast(key, elem) if err != nil { return reflect.Value{}, err } v.Elem().Set(elem) return v, nil case reflect.Slice: elemType := v.Type().Elem() var elem reflect.Value if elemType.Kind() == reflect.Interface { elem = makeMapStringInterface() } else { elem = reflect.New(elemType).Elem() } elem2, err := d.handleArrayTable(key, elem) if err != nil { return reflect.Value{}, err } if elem2.IsValid() { elem = elem2 } return reflect.Append(v, elem), nil case reflect.Array: idx := d.arrayIndex(true, v) if idx >= v.Len() { return v, fmt.Errorf("toml: cannot decode array table into %s at position %d", v.Type(), idx) } elem := v.Index(idx) _, err := d.handleArrayTable(key, elem) return v, err default: return reflect.Value{}, fmt.Errorf("toml: cannot decode array table into a %s", v.Type()) } } // When parsing an array table expression, each part of the key needs to be // evaluated like a normal key, but if it returns a collection, it also needs to // point to the last element of the collection. Unless it is the last part of // the key, then it needs to create a new element at the end. func (d *decoder) handleArrayTableCollection(key ast.Iterator, v reflect.Value) (reflect.Value, error) { if key.IsLast() { return d.handleArrayTableCollectionLast(key, v) } switch v.Kind() { case reflect.Ptr: elem := v.Elem() if !elem.IsValid() { ptr := reflect.New(v.Type().Elem()) v.Set(ptr) elem = ptr.Elem() } elem, err := d.handleArrayTableCollection(key, elem) if err != nil { return reflect.Value{}, err } if elem.IsValid() { v.Elem().Set(elem) } return v, nil case reflect.Slice: elem := v.Index(v.Len() - 1) x, err := d.handleArrayTable(key, elem) if err != nil || d.skipUntilTable { return reflect.Value{}, err } if x.IsValid() { elem.Set(x) } return v, err case reflect.Array: idx := d.arrayIndex(false, v) if idx >= v.Len() { return v, fmt.Errorf("toml: cannot decode array table into %s at position %d", v.Type(), idx) } elem := v.Index(idx) _, err := d.handleArrayTable(key, elem) return v, err } return d.handleArrayTable(key, v) } func (d *decoder) handleKeyPart(key ast.Iterator, v reflect.Value, nextFn handlerFn, makeFn valueMakerFn) (reflect.Value, error) { var rv reflect.Value // First, dispatch over v to make sure it is a valid object. // There is no guarantee over what it could be. switch v.Kind() { case reflect.Ptr: elem := v.Elem() if !elem.IsValid() { v.Set(reflect.New(v.Type().Elem())) } elem = v.Elem() return d.handleKeyPart(key, elem, nextFn, makeFn) case reflect.Map: vt := v.Type() // Create the key for the map element. Convert to key type. mk := reflect.ValueOf(string(key.Node().Data)).Convert(vt.Key()) // If the map does not exist, create it. if v.IsNil() { vt := v.Type() v = reflect.MakeMap(vt) rv = v } mv := v.MapIndex(mk) set := false if !mv.IsValid() { // If there is no value in the map, create a new one according to // the map type. If the element type is interface, create either a // map[string]interface{} or a []interface{} depending on whether // this is the last part of the array table key. t := vt.Elem() if t.Kind() == reflect.Interface { mv = makeFn() } else { mv = reflect.New(t).Elem() } set = true } else if mv.Kind() == reflect.Interface { mv = mv.Elem() if !mv.IsValid() { mv = makeFn() } set = true } else if !mv.CanAddr() { vt := v.Type() t := vt.Elem() oldmv := mv mv = reflect.New(t).Elem() mv.Set(oldmv) set = true } x, err := nextFn(key, mv) if err != nil { return reflect.Value{}, err } if x.IsValid() { mv = x set = true } if set { v.SetMapIndex(mk, mv) } case reflect.Struct: path, found := structFieldPath(v, string(key.Node().Data)) if !found { d.skipUntilTable = true return reflect.Value{}, nil } if d.errorContext == nil { d.errorContext = new(errorContext) } t := v.Type() d.errorContext.Struct = t d.errorContext.Field = path f := fieldByIndex(v, path) x, err := nextFn(key, f) if err != nil || d.skipUntilTable { return reflect.Value{}, err } if x.IsValid() { f.Set(x) } d.errorContext.Field = nil d.errorContext.Struct = nil case reflect.Interface: if v.Elem().IsValid() { v = v.Elem() } else { v = makeMapStringInterface() } x, err := d.handleKeyPart(key, v, nextFn, makeFn) if err != nil { return reflect.Value{}, err } if x.IsValid() { v = x } rv = v default: panic(fmt.Errorf("unhandled part: %s", v.Kind())) } return rv, nil } // HandleArrayTablePart navigates the Go structure v using the key v. It is // only used for the prefix (non-last) parts of an array-table. When // encountering a collection, it should go to the last element. func (d *decoder) handleArrayTablePart(key ast.Iterator, v reflect.Value) (reflect.Value, error) { var makeFn valueMakerFn if key.IsLast() { makeFn = makeSliceInterface } else { makeFn = makeMapStringInterface } return d.handleKeyPart(key, v, d.handleArrayTableCollection, makeFn) } // HandleTable returns a reference when it has checked the next expression but // cannot handle it. func (d *decoder) handleTable(key ast.Iterator, v reflect.Value) (reflect.Value, error) { if v.Kind() == reflect.Slice { if v.Len() == 0 { return reflect.Value{}, newDecodeError(key.Node().Data, "cannot store a table in a slice") } elem := v.Index(v.Len() - 1) x, err := d.handleTable(key, elem) if err != nil { return reflect.Value{}, err } if x.IsValid() { elem.Set(x) } return reflect.Value{}, nil } if key.Next() { // Still scoping the key return d.handleTablePart(key, v) } // Done scoping the key. // Now handle all the key-value expressions in this table. return d.handleKeyValues(v) } // Handle root expressions until the end of the document or the next // non-key-value. func (d *decoder) handleKeyValues(v reflect.Value) (reflect.Value, error) { var rv reflect.Value for d.nextExpr() { expr := d.expr() if expr.Kind != ast.KeyValue { // Stash the expression so that fromParser can just loop and use // the right handler. // We could just recurse ourselves here, but at least this gives a // chance to pop the stack a bit. d.stashExpr() break } err := d.seen.CheckExpression(expr) if err != nil { return reflect.Value{}, err } x, err := d.handleKeyValue(expr, v) if err != nil { return reflect.Value{}, err } if x.IsValid() { v = x rv = x } } return rv, nil } type ( handlerFn func(key ast.Iterator, v reflect.Value) (reflect.Value, error) valueMakerFn func() reflect.Value ) func makeMapStringInterface() reflect.Value { return reflect.MakeMap(mapStringInterfaceType) } func makeSliceInterface() reflect.Value { return reflect.MakeSlice(sliceInterfaceType, 0, 16) } func (d *decoder) handleTablePart(key ast.Iterator, v reflect.Value) (reflect.Value, error) { return d.handleKeyPart(key, v, d.handleTable, makeMapStringInterface) } func (d *decoder) tryTextUnmarshaler(node *ast.Node, v reflect.Value) (bool, error) { // Special case for time, because we allow to unmarshal to it from // different kind of AST nodes. if v.Type() == timeType { return false, nil } if v.CanAddr() && v.Addr().Type().Implements(textUnmarshalerType) { err := v.Addr().Interface().(encoding.TextUnmarshaler).UnmarshalText(node.Data) if err != nil { return false, newDecodeError(d.p.Raw(node.Raw), "%w", err) } return true, nil } return false, nil } func (d *decoder) handleValue(value *ast.Node, v reflect.Value) error { for v.Kind() == reflect.Ptr { v = initAndDereferencePointer(v) } ok, err := d.tryTextUnmarshaler(value, v) if ok || err != nil { return err } switch value.Kind { case ast.String: return d.unmarshalString(value, v) case ast.Integer: return d.unmarshalInteger(value, v) case ast.Float: return d.unmarshalFloat(value, v) case ast.Bool: return d.unmarshalBool(value, v) case ast.DateTime: return d.unmarshalDateTime(value, v) case ast.LocalDate: return d.unmarshalLocalDate(value, v) case ast.LocalTime: return d.unmarshalLocalTime(value, v) case ast.LocalDateTime: return d.unmarshalLocalDateTime(value, v) case ast.InlineTable: return d.unmarshalInlineTable(value, v) case ast.Array: return d.unmarshalArray(value, v) default: panic(fmt.Errorf("handleValue not implemented for %s", value.Kind)) } } func (d *decoder) unmarshalArray(array *ast.Node, v reflect.Value) error { switch v.Kind() { case reflect.Slice: if v.IsNil() { v.Set(reflect.MakeSlice(v.Type(), 0, 16)) } else { v.SetLen(0) } case reflect.Array: // arrays are always initialized case reflect.Interface: elem := v.Elem() if !elem.IsValid() { elem = reflect.New(sliceInterfaceType).Elem() elem.Set(reflect.MakeSlice(sliceInterfaceType, 0, 16)) } else if elem.Kind() == reflect.Slice { if elem.Type() != sliceInterfaceType { elem = reflect.New(sliceInterfaceType).Elem() elem.Set(reflect.MakeSlice(sliceInterfaceType, 0, 16)) } else if !elem.CanSet() { nelem := reflect.New(sliceInterfaceType).Elem() nelem.Set(reflect.MakeSlice(sliceInterfaceType, elem.Len(), elem.Cap())) reflect.Copy(nelem, elem) elem = nelem } } err := d.unmarshalArray(array, elem) if err != nil { return err } v.Set(elem) return nil default: // TODO: use newDecodeError, but first the parser needs to fill // array.Data. return d.typeMismatchError("array", v.Type()) } elemType := v.Type().Elem() it := array.Children() idx := 0 for it.Next() { n := it.Node() // TODO: optimize if v.Kind() == reflect.Slice { elem := reflect.New(elemType).Elem() err := d.handleValue(n, elem) if err != nil { return err } v.Set(reflect.Append(v, elem)) } else { // array if idx >= v.Len() { return nil } elem := v.Index(idx) err := d.handleValue(n, elem) if err != nil { return err } idx++ } } return nil } func (d *decoder) unmarshalInlineTable(itable *ast.Node, v reflect.Value) error { // Make sure v is an initialized object. switch v.Kind() { case reflect.Map: if v.IsNil() { v.Set(reflect.MakeMap(v.Type())) } case reflect.Struct: // structs are always initialized. case reflect.Interface: elem := v.Elem() if !elem.IsValid() { elem = makeMapStringInterface() v.Set(elem) } return d.unmarshalInlineTable(itable, elem) default: return newDecodeError(itable.Data, "cannot store inline table in Go type %s", v.Kind()) } it := itable.Children() for it.Next() { n := it.Node() x, err := d.handleKeyValue(n, v) if err != nil { return err } if x.IsValid() { v = x } } return nil } func (d *decoder) unmarshalDateTime(value *ast.Node, v reflect.Value) error { dt, err := parseDateTime(value.Data) if err != nil { return err } v.Set(reflect.ValueOf(dt)) return nil } func (d *decoder) unmarshalLocalDate(value *ast.Node, v reflect.Value) error { ld, err := parseLocalDate(value.Data) if err != nil { return err } if v.Type() == timeType { cast := ld.AsTime(time.Local) v.Set(reflect.ValueOf(cast)) return nil } v.Set(reflect.ValueOf(ld)) return nil } func (d *decoder) unmarshalLocalTime(value *ast.Node, v reflect.Value) error { lt, rest, err := parseLocalTime(value.Data) if err != nil { return err } if len(rest) > 0 { return newDecodeError(rest, "extra characters at the end of a local time") } v.Set(reflect.ValueOf(lt)) return nil } func (d *decoder) unmarshalLocalDateTime(value *ast.Node, v reflect.Value) error { ldt, rest, err := parseLocalDateTime(value.Data) if err != nil { return err } if len(rest) > 0 { return newDecodeError(rest, "extra characters at the end of a local date time") } if v.Type() == timeType { cast := ldt.AsTime(time.Local) v.Set(reflect.ValueOf(cast)) return nil } v.Set(reflect.ValueOf(ldt)) return nil } func (d *decoder) unmarshalBool(value *ast.Node, v reflect.Value) error { b := value.Data[0] == 't' switch v.Kind() { case reflect.Bool: v.SetBool(b) case reflect.Interface: v.Set(reflect.ValueOf(b)) default: return newDecodeError(value.Data, "cannot assign boolean to a %t", b) } return nil } func (d *decoder) unmarshalFloat(value *ast.Node, v reflect.Value) error { f, err := parseFloat(value.Data) if err != nil { return err } switch v.Kind() { case reflect.Float64: v.SetFloat(f) case reflect.Float32: if f > math.MaxFloat32 { return newDecodeError(value.Data, "number %f does not fit in a float32", f) } v.SetFloat(f) case reflect.Interface: v.Set(reflect.ValueOf(f)) default: return newDecodeError(value.Data, "float cannot be assigned to %s", v.Kind()) } return nil } const ( maxInt = int64(^uint(0) >> 1) minInt = -maxInt - 1 ) // Maximum value of uint for decoding. Currently the decoder parses the integer // into an int64. As a result, on architectures where uint is 64 bits, the // effective maximum uint we can decode is the maximum of int64. On // architectures where uint is 32 bits, the maximum value we can decode is // lower: the maximum of uint32. I didn't find a way to figure out this value at // compile time, so it is computed during initialization. var maxUint int64 = math.MaxInt64 func init() { m := uint64(^uint(0)) if m < uint64(maxUint) { maxUint = int64(m) } } func (d *decoder) unmarshalInteger(value *ast.Node, v reflect.Value) error { i, err := parseInteger(value.Data) if err != nil { return err } var r reflect.Value switch v.Kind() { case reflect.Int64: v.SetInt(i) return nil case reflect.Int32: if i < math.MinInt32 || i > math.MaxInt32 { return fmt.Errorf("toml: number %d does not fit in an int32", i) } r = reflect.ValueOf(int32(i)) case reflect.Int16: if i < math.MinInt16 || i > math.MaxInt16 { return fmt.Errorf("toml: number %d does not fit in an int16", i) } r = reflect.ValueOf(int16(i)) case reflect.Int8: if i < math.MinInt8 || i > math.MaxInt8 { return fmt.Errorf("toml: number %d does not fit in an int8", i) } r = reflect.ValueOf(int8(i)) case reflect.Int: if i < minInt || i > maxInt { return fmt.Errorf("toml: number %d does not fit in an int", i) } r = reflect.ValueOf(int(i)) case reflect.Uint64: if i < 0 { return fmt.Errorf("toml: negative number %d does not fit in an uint64", i) } r = reflect.ValueOf(uint64(i)) case reflect.Uint32: if i < 0 || i > math.MaxUint32 { return fmt.Errorf("toml: negative number %d does not fit in an uint32", i) } r = reflect.ValueOf(uint32(i)) case reflect.Uint16: if i < 0 || i > math.MaxUint16 { return fmt.Errorf("toml: negative number %d does not fit in an uint16", i) } r = reflect.ValueOf(uint16(i)) case reflect.Uint8: if i < 0 || i > math.MaxUint8 { return fmt.Errorf("toml: negative number %d does not fit in an uint8", i) } r = reflect.ValueOf(uint8(i)) case reflect.Uint: if i < 0 || i > maxUint { return fmt.Errorf("toml: negative number %d does not fit in an uint", i) } r = reflect.ValueOf(uint(i)) case reflect.Interface: r = reflect.ValueOf(i) default: return d.typeMismatchError("integer", v.Type()) } if !r.Type().AssignableTo(v.Type()) { r = r.Convert(v.Type()) } v.Set(r) return nil } func (d *decoder) unmarshalString(value *ast.Node, v reflect.Value) error { switch v.Kind() { case reflect.String: v.SetString(string(value.Data)) case reflect.Interface: v.Set(reflect.ValueOf(string(value.Data))) default: return newDecodeError(d.p.Raw(value.Raw), "cannot store TOML string into a Go %s", v.Kind()) } return nil } func (d *decoder) handleKeyValue(expr *ast.Node, v reflect.Value) (reflect.Value, error) { d.strict.EnterKeyValue(expr) v, err := d.handleKeyValueInner(expr.Key(), expr.Value(), v) if d.skipUntilTable { d.strict.MissingField(expr) d.skipUntilTable = false } d.strict.ExitKeyValue(expr) return v, err } func (d *decoder) handleKeyValueInner(key ast.Iterator, value *ast.Node, v reflect.Value) (reflect.Value, error) { if key.Next() { // Still scoping the key return d.handleKeyValuePart(key, value, v) } // Done scoping the key. // v is whatever Go value we need to fill. return reflect.Value{}, d.handleValue(value, v) } func (d *decoder) handleKeyValuePart(key ast.Iterator, value *ast.Node, v reflect.Value) (reflect.Value, error) { // contains the replacement for v var rv reflect.Value // First, dispatch over v to make sure it is a valid object. // There is no guarantee over what it could be. switch v.Kind() { case reflect.Map: vt := v.Type() mk := reflect.ValueOf(string(key.Node().Data)) mkt := stringType keyType := vt.Key() if !mkt.AssignableTo(keyType) { if !mkt.ConvertibleTo(keyType) { return reflect.Value{}, fmt.Errorf("toml: cannot convert map key of type %s to expected type %s", mkt, keyType) } mk = mk.Convert(keyType) } // If the map does not exist, create it. if v.IsNil() { v = reflect.MakeMap(vt) rv = v } mv := v.MapIndex(mk) set := false if !mv.IsValid() { set = true mv = reflect.New(v.Type().Elem()).Elem() } else { if key.IsLast() { var x interface{} mv = reflect.ValueOf(&x).Elem() set = true } } nv, err := d.handleKeyValueInner(key, value, mv) if err != nil { return reflect.Value{}, err } if nv.IsValid() { mv = nv set = true } if set { v.SetMapIndex(mk, mv) } case reflect.Struct: path, found := structFieldPath(v, string(key.Node().Data)) if !found { d.skipUntilTable = true break } if d.errorContext == nil { d.errorContext = new(errorContext) } t := v.Type() d.errorContext.Struct = t d.errorContext.Field = path f := fieldByIndex(v, path) x, err := d.handleKeyValueInner(key, value, f) if err != nil { return reflect.Value{}, err } if x.IsValid() { f.Set(x) } d.errorContext.Struct = nil d.errorContext.Field = nil case reflect.Interface: v = v.Elem() // Following encoding/json: decoding an object into an // interface{}, it needs to always hold a // map[string]interface{}. This is for the types to be // consistent whether a previous value was set or not. if !v.IsValid() || v.Type() != mapStringInterfaceType { v = makeMapStringInterface() } x, err := d.handleKeyValuePart(key, value, v) if err != nil { return reflect.Value{}, err } if x.IsValid() { v = x } rv = v case reflect.Ptr: elem := v.Elem() if !elem.IsValid() { ptr := reflect.New(v.Type().Elem()) v.Set(ptr) rv = v elem = ptr.Elem() } elem2, err := d.handleKeyValuePart(key, value, elem) if err != nil { return reflect.Value{}, err } if elem2.IsValid() { elem = elem2 } v.Elem().Set(elem) default: return reflect.Value{}, fmt.Errorf("unhandled kv part: %s", v.Kind()) } return rv, nil } func initAndDereferencePointer(v reflect.Value) reflect.Value { var elem reflect.Value if v.IsNil() { ptr := reflect.New(v.Type().Elem()) v.Set(ptr) } elem = v.Elem() return elem } // Same as reflect.Value.FieldByIndex, but creates pointers if needed. func fieldByIndex(v reflect.Value, path []int) reflect.Value { for i, x := range path { v = v.Field(x) if i < len(path)-1 && v.Kind() == reflect.Ptr { if v.IsNil() { v.Set(reflect.New(v.Type().Elem())) } v = v.Elem() } } return v } type fieldPathsMap = map[string][]int var globalFieldPathsCache atomic.Value // map[danger.TypeID]fieldPathsMap func structFieldPath(v reflect.Value, name string) ([]int, bool) { t := v.Type() cache, _ := globalFieldPathsCache.Load().(map[danger.TypeID]fieldPathsMap) fieldPaths, ok := cache[danger.MakeTypeID(t)] if !ok { fieldPaths = map[string][]int{} forEachField(t, nil, func(name string, path []int) { fieldPaths[name] = path // extra copy for the case-insensitive match fieldPaths[strings.ToLower(name)] = path }) newCache := make(map[danger.TypeID]fieldPathsMap, len(cache)+1) newCache[danger.MakeTypeID(t)] = fieldPaths for k, v := range cache { newCache[k] = v } globalFieldPathsCache.Store(newCache) } path, ok := fieldPaths[name] if !ok { path, ok = fieldPaths[strings.ToLower(name)] } return path, ok } func forEachField(t reflect.Type, path []int, do func(name string, path []int)) { n := t.NumField() for i := 0; i < n; i++ { f := t.Field(i) if !f.Anonymous && f.PkgPath != "" { // only consider exported fields. continue } fieldPath := append(path, i) fieldPath = fieldPath[:len(fieldPath):len(fieldPath)] name := f.Tag.Get("toml") if name == "-" { continue } if i := strings.IndexByte(name, ','); i >= 0 { name = name[:i] } if f.Anonymous && name == "" { t2 := f.Type if t2.Kind() == reflect.Ptr { t2 = t2.Elem() } if t2.Kind() == reflect.Struct { forEachField(t2, fieldPath, do) } continue } if name == "" { name = f.Name } do(name, fieldPath) } }