--- /dev/null
+package hcl
+
+import (
+ "errors"
+ "fmt"
+ "reflect"
+ "sort"
+ "strconv"
+ "strings"
+
+ "github.com/hashicorp/hcl/hcl/ast"
+ "github.com/hashicorp/hcl/hcl/parser"
+ "github.com/hashicorp/hcl/hcl/token"
+)
+
+// This is the tag to use with structures to have settings for HCL
+const tagName = "hcl"
+
+var (
+ // nodeType holds a reference to the type of ast.Node
+ nodeType reflect.Type = findNodeType()
+)
+
+// Unmarshal accepts a byte slice as input and writes the
+// data to the value pointed to by v.
+func Unmarshal(bs []byte, v interface{}) error {
+ root, err := parse(bs)
+ if err != nil {
+ return err
+ }
+
+ return DecodeObject(v, root)
+}
+
+// Decode reads the given input and decodes it into the structure
+// given by `out`.
+func Decode(out interface{}, in string) error {
+ obj, err := Parse(in)
+ if err != nil {
+ return err
+ }
+
+ return DecodeObject(out, obj)
+}
+
+// DecodeObject is a lower-level version of Decode. It decodes a
+// raw Object into the given output.
+func DecodeObject(out interface{}, n ast.Node) error {
+ val := reflect.ValueOf(out)
+ if val.Kind() != reflect.Ptr {
+ return errors.New("result must be a pointer")
+ }
+
+ // If we have the file, we really decode the root node
+ if f, ok := n.(*ast.File); ok {
+ n = f.Node
+ }
+
+ var d decoder
+ return d.decode("root", n, val.Elem())
+}
+
+type decoder struct {
+ stack []reflect.Kind
+}
+
+func (d *decoder) decode(name string, node ast.Node, result reflect.Value) error {
+ k := result
+
+ // If we have an interface with a valid value, we use that
+ // for the check.
+ if result.Kind() == reflect.Interface {
+ elem := result.Elem()
+ if elem.IsValid() {
+ k = elem
+ }
+ }
+
+ // Push current onto stack unless it is an interface.
+ if k.Kind() != reflect.Interface {
+ d.stack = append(d.stack, k.Kind())
+
+ // Schedule a pop
+ defer func() {
+ d.stack = d.stack[:len(d.stack)-1]
+ }()
+ }
+
+ switch k.Kind() {
+ case reflect.Bool:
+ return d.decodeBool(name, node, result)
+ case reflect.Float32, reflect.Float64:
+ return d.decodeFloat(name, node, result)
+ case reflect.Int, reflect.Int32, reflect.Int64:
+ return d.decodeInt(name, node, result)
+ case reflect.Interface:
+ // When we see an interface, we make our own thing
+ return d.decodeInterface(name, node, result)
+ case reflect.Map:
+ return d.decodeMap(name, node, result)
+ case reflect.Ptr:
+ return d.decodePtr(name, node, result)
+ case reflect.Slice:
+ return d.decodeSlice(name, node, result)
+ case reflect.String:
+ return d.decodeString(name, node, result)
+ case reflect.Struct:
+ return d.decodeStruct(name, node, result)
+ default:
+ return &parser.PosError{
+ Pos: node.Pos(),
+ Err: fmt.Errorf("%s: unknown kind to decode into: %s", name, k.Kind()),
+ }
+ }
+}
+
+func (d *decoder) decodeBool(name string, node ast.Node, result reflect.Value) error {
+ switch n := node.(type) {
+ case *ast.LiteralType:
+ if n.Token.Type == token.BOOL {
+ v, err := strconv.ParseBool(n.Token.Text)
+ if err != nil {
+ return err
+ }
+
+ result.Set(reflect.ValueOf(v))
+ return nil
+ }
+ }
+
+ return &parser.PosError{
+ Pos: node.Pos(),
+ Err: fmt.Errorf("%s: unknown type %T", name, node),
+ }
+}
+
+func (d *decoder) decodeFloat(name string, node ast.Node, result reflect.Value) error {
+ switch n := node.(type) {
+ case *ast.LiteralType:
+ if n.Token.Type == token.FLOAT || n.Token.Type == token.NUMBER {
+ v, err := strconv.ParseFloat(n.Token.Text, 64)
+ if err != nil {
+ return err
+ }
+
+ result.Set(reflect.ValueOf(v).Convert(result.Type()))
+ return nil
+ }
+ }
+
+ return &parser.PosError{
+ Pos: node.Pos(),
+ Err: fmt.Errorf("%s: unknown type %T", name, node),
+ }
+}
+
+func (d *decoder) decodeInt(name string, node ast.Node, result reflect.Value) error {
+ switch n := node.(type) {
+ case *ast.LiteralType:
+ switch n.Token.Type {
+ case token.NUMBER:
+ v, err := strconv.ParseInt(n.Token.Text, 0, 0)
+ if err != nil {
+ return err
+ }
+
+ if result.Kind() == reflect.Interface {
+ result.Set(reflect.ValueOf(int(v)))
+ } else {
+ result.SetInt(v)
+ }
+ return nil
+ case token.STRING:
+ v, err := strconv.ParseInt(n.Token.Value().(string), 0, 0)
+ if err != nil {
+ return err
+ }
+
+ if result.Kind() == reflect.Interface {
+ result.Set(reflect.ValueOf(int(v)))
+ } else {
+ result.SetInt(v)
+ }
+ return nil
+ }
+ }
+
+ return &parser.PosError{
+ Pos: node.Pos(),
+ Err: fmt.Errorf("%s: unknown type %T", name, node),
+ }
+}
+
+func (d *decoder) decodeInterface(name string, node ast.Node, result reflect.Value) error {
+ // When we see an ast.Node, we retain the value to enable deferred decoding.
+ // Very useful in situations where we want to preserve ast.Node information
+ // like Pos
+ if result.Type() == nodeType && result.CanSet() {
+ result.Set(reflect.ValueOf(node))
+ return nil
+ }
+
+ var set reflect.Value
+ redecode := true
+
+ // For testing types, ObjectType should just be treated as a list. We
+ // set this to a temporary var because we want to pass in the real node.
+ testNode := node
+ if ot, ok := node.(*ast.ObjectType); ok {
+ testNode = ot.List
+ }
+
+ switch n := testNode.(type) {
+ case *ast.ObjectList:
+ // If we're at the root or we're directly within a slice, then we
+ // decode objects into map[string]interface{}, otherwise we decode
+ // them into lists.
+ if len(d.stack) == 0 || d.stack[len(d.stack)-1] == reflect.Slice {
+ var temp map[string]interface{}
+ tempVal := reflect.ValueOf(temp)
+ result := reflect.MakeMap(
+ reflect.MapOf(
+ reflect.TypeOf(""),
+ tempVal.Type().Elem()))
+
+ set = result
+ } else {
+ var temp []map[string]interface{}
+ tempVal := reflect.ValueOf(temp)
+ result := reflect.MakeSlice(
+ reflect.SliceOf(tempVal.Type().Elem()), 0, len(n.Items))
+ set = result
+ }
+ case *ast.ObjectType:
+ // If we're at the root or we're directly within a slice, then we
+ // decode objects into map[string]interface{}, otherwise we decode
+ // them into lists.
+ if len(d.stack) == 0 || d.stack[len(d.stack)-1] == reflect.Slice {
+ var temp map[string]interface{}
+ tempVal := reflect.ValueOf(temp)
+ result := reflect.MakeMap(
+ reflect.MapOf(
+ reflect.TypeOf(""),
+ tempVal.Type().Elem()))
+
+ set = result
+ } else {
+ var temp []map[string]interface{}
+ tempVal := reflect.ValueOf(temp)
+ result := reflect.MakeSlice(
+ reflect.SliceOf(tempVal.Type().Elem()), 0, 1)
+ set = result
+ }
+ case *ast.ListType:
+ var temp []interface{}
+ tempVal := reflect.ValueOf(temp)
+ result := reflect.MakeSlice(
+ reflect.SliceOf(tempVal.Type().Elem()), 0, 0)
+ set = result
+ case *ast.LiteralType:
+ switch n.Token.Type {
+ case token.BOOL:
+ var result bool
+ set = reflect.Indirect(reflect.New(reflect.TypeOf(result)))
+ case token.FLOAT:
+ var result float64
+ set = reflect.Indirect(reflect.New(reflect.TypeOf(result)))
+ case token.NUMBER:
+ var result int
+ set = reflect.Indirect(reflect.New(reflect.TypeOf(result)))
+ case token.STRING, token.HEREDOC:
+ set = reflect.Indirect(reflect.New(reflect.TypeOf("")))
+ default:
+ return &parser.PosError{
+ Pos: node.Pos(),
+ Err: fmt.Errorf("%s: cannot decode into interface: %T", name, node),
+ }
+ }
+ default:
+ return fmt.Errorf(
+ "%s: cannot decode into interface: %T",
+ name, node)
+ }
+
+ // Set the result to what its supposed to be, then reset
+ // result so we don't reflect into this method anymore.
+ result.Set(set)
+
+ if redecode {
+ // Revisit the node so that we can use the newly instantiated
+ // thing and populate it.
+ if err := d.decode(name, node, result); err != nil {
+ return err
+ }
+ }
+
+ return nil
+}
+
+func (d *decoder) decodeMap(name string, node ast.Node, result reflect.Value) error {
+ if item, ok := node.(*ast.ObjectItem); ok {
+ node = &ast.ObjectList{Items: []*ast.ObjectItem{item}}
+ }
+
+ if ot, ok := node.(*ast.ObjectType); ok {
+ node = ot.List
+ }
+
+ n, ok := node.(*ast.ObjectList)
+ if !ok {
+ return &parser.PosError{
+ Pos: node.Pos(),
+ Err: fmt.Errorf("%s: not an object type for map (%T)", name, node),
+ }
+ }
+
+ // If we have an interface, then we can address the interface,
+ // but not the slice itself, so get the element but set the interface
+ set := result
+ if result.Kind() == reflect.Interface {
+ result = result.Elem()
+ }
+
+ resultType := result.Type()
+ resultElemType := resultType.Elem()
+ resultKeyType := resultType.Key()
+ if resultKeyType.Kind() != reflect.String {
+ return &parser.PosError{
+ Pos: node.Pos(),
+ Err: fmt.Errorf("%s: map must have string keys", name),
+ }
+ }
+
+ // Make a map if it is nil
+ resultMap := result
+ if result.IsNil() {
+ resultMap = reflect.MakeMap(
+ reflect.MapOf(resultKeyType, resultElemType))
+ }
+
+ // Go through each element and decode it.
+ done := make(map[string]struct{})
+ for _, item := range n.Items {
+ if item.Val == nil {
+ continue
+ }
+
+ // github.com/hashicorp/terraform/issue/5740
+ if len(item.Keys) == 0 {
+ return &parser.PosError{
+ Pos: node.Pos(),
+ Err: fmt.Errorf("%s: map must have string keys", name),
+ }
+ }
+
+ // Get the key we're dealing with, which is the first item
+ keyStr := item.Keys[0].Token.Value().(string)
+
+ // If we've already processed this key, then ignore it
+ if _, ok := done[keyStr]; ok {
+ continue
+ }
+
+ // Determine the value. If we have more than one key, then we
+ // get the objectlist of only these keys.
+ itemVal := item.Val
+ if len(item.Keys) > 1 {
+ itemVal = n.Filter(keyStr)
+ done[keyStr] = struct{}{}
+ }
+
+ // Make the field name
+ fieldName := fmt.Sprintf("%s.%s", name, keyStr)
+
+ // Get the key/value as reflection values
+ key := reflect.ValueOf(keyStr)
+ val := reflect.Indirect(reflect.New(resultElemType))
+
+ // If we have a pre-existing value in the map, use that
+ oldVal := resultMap.MapIndex(key)
+ if oldVal.IsValid() {
+ val.Set(oldVal)
+ }
+
+ // Decode!
+ if err := d.decode(fieldName, itemVal, val); err != nil {
+ return err
+ }
+
+ // Set the value on the map
+ resultMap.SetMapIndex(key, val)
+ }
+
+ // Set the final map if we can
+ set.Set(resultMap)
+ return nil
+}
+
+func (d *decoder) decodePtr(name string, node ast.Node, result reflect.Value) error {
+ // Create an element of the concrete (non pointer) type and decode
+ // into that. Then set the value of the pointer to this type.
+ resultType := result.Type()
+ resultElemType := resultType.Elem()
+ val := reflect.New(resultElemType)
+ if err := d.decode(name, node, reflect.Indirect(val)); err != nil {
+ return err
+ }
+
+ result.Set(val)
+ return nil
+}
+
+func (d *decoder) decodeSlice(name string, node ast.Node, result reflect.Value) error {
+ // If we have an interface, then we can address the interface,
+ // but not the slice itself, so get the element but set the interface
+ set := result
+ if result.Kind() == reflect.Interface {
+ result = result.Elem()
+ }
+ // Create the slice if it isn't nil
+ resultType := result.Type()
+ resultElemType := resultType.Elem()
+ if result.IsNil() {
+ resultSliceType := reflect.SliceOf(resultElemType)
+ result = reflect.MakeSlice(
+ resultSliceType, 0, 0)
+ }
+
+ // Figure out the items we'll be copying into the slice
+ var items []ast.Node
+ switch n := node.(type) {
+ case *ast.ObjectList:
+ items = make([]ast.Node, len(n.Items))
+ for i, item := range n.Items {
+ items[i] = item
+ }
+ case *ast.ObjectType:
+ items = []ast.Node{n}
+ case *ast.ListType:
+ items = n.List
+ default:
+ return &parser.PosError{
+ Pos: node.Pos(),
+ Err: fmt.Errorf("unknown slice type: %T", node),
+ }
+ }
+
+ for i, item := range items {
+ fieldName := fmt.Sprintf("%s[%d]", name, i)
+
+ // Decode
+ val := reflect.Indirect(reflect.New(resultElemType))
+
+ // if item is an object that was decoded from ambiguous JSON and
+ // flattened, make sure it's expanded if it needs to decode into a
+ // defined structure.
+ item := expandObject(item, val)
+
+ if err := d.decode(fieldName, item, val); err != nil {
+ return err
+ }
+
+ // Append it onto the slice
+ result = reflect.Append(result, val)
+ }
+
+ set.Set(result)
+ return nil
+}
+
+// expandObject detects if an ambiguous JSON object was flattened to a List which
+// should be decoded into a struct, and expands the ast to properly deocode.
+func expandObject(node ast.Node, result reflect.Value) ast.Node {
+ item, ok := node.(*ast.ObjectItem)
+ if !ok {
+ return node
+ }
+
+ elemType := result.Type()
+
+ // our target type must be a struct
+ switch elemType.Kind() {
+ case reflect.Ptr:
+ switch elemType.Elem().Kind() {
+ case reflect.Struct:
+ //OK
+ default:
+ return node
+ }
+ case reflect.Struct:
+ //OK
+ default:
+ return node
+ }
+
+ // A list value will have a key and field name. If it had more fields,
+ // it wouldn't have been flattened.
+ if len(item.Keys) != 2 {
+ return node
+ }
+
+ keyToken := item.Keys[0].Token
+ item.Keys = item.Keys[1:]
+
+ // we need to un-flatten the ast enough to decode
+ newNode := &ast.ObjectItem{
+ Keys: []*ast.ObjectKey{
+ &ast.ObjectKey{
+ Token: keyToken,
+ },
+ },
+ Val: &ast.ObjectType{
+ List: &ast.ObjectList{
+ Items: []*ast.ObjectItem{item},
+ },
+ },
+ }
+
+ return newNode
+}
+
+func (d *decoder) decodeString(name string, node ast.Node, result reflect.Value) error {
+ switch n := node.(type) {
+ case *ast.LiteralType:
+ switch n.Token.Type {
+ case token.NUMBER:
+ result.Set(reflect.ValueOf(n.Token.Text).Convert(result.Type()))
+ return nil
+ case token.STRING, token.HEREDOC:
+ result.Set(reflect.ValueOf(n.Token.Value()).Convert(result.Type()))
+ return nil
+ }
+ }
+
+ return &parser.PosError{
+ Pos: node.Pos(),
+ Err: fmt.Errorf("%s: unknown type for string %T", name, node),
+ }
+}
+
+func (d *decoder) decodeStruct(name string, node ast.Node, result reflect.Value) error {
+ var item *ast.ObjectItem
+ if it, ok := node.(*ast.ObjectItem); ok {
+ item = it
+ node = it.Val
+ }
+
+ if ot, ok := node.(*ast.ObjectType); ok {
+ node = ot.List
+ }
+
+ // Handle the special case where the object itself is a literal. Previously
+ // the yacc parser would always ensure top-level elements were arrays. The new
+ // parser does not make the same guarantees, thus we need to convert any
+ // top-level literal elements into a list.
+ if _, ok := node.(*ast.LiteralType); ok && item != nil {
+ node = &ast.ObjectList{Items: []*ast.ObjectItem{item}}
+ }
+
+ list, ok := node.(*ast.ObjectList)
+ if !ok {
+ return &parser.PosError{
+ Pos: node.Pos(),
+ Err: fmt.Errorf("%s: not an object type for struct (%T)", name, node),
+ }
+ }
+
+ // This slice will keep track of all the structs we'll be decoding.
+ // There can be more than one struct if there are embedded structs
+ // that are squashed.
+ structs := make([]reflect.Value, 1, 5)
+ structs[0] = result
+
+ // Compile the list of all the fields that we're going to be decoding
+ // from all the structs.
+ type field struct {
+ field reflect.StructField
+ val reflect.Value
+ }
+ fields := []field{}
+ for len(structs) > 0 {
+ structVal := structs[0]
+ structs = structs[1:]
+
+ structType := structVal.Type()
+ for i := 0; i < structType.NumField(); i++ {
+ fieldType := structType.Field(i)
+ tagParts := strings.Split(fieldType.Tag.Get(tagName), ",")
+
+ // Ignore fields with tag name "-"
+ if tagParts[0] == "-" {
+ continue
+ }
+
+ if fieldType.Anonymous {
+ fieldKind := fieldType.Type.Kind()
+ if fieldKind != reflect.Struct {
+ return &parser.PosError{
+ Pos: node.Pos(),
+ Err: fmt.Errorf("%s: unsupported type to struct: %s",
+ fieldType.Name, fieldKind),
+ }
+ }
+
+ // We have an embedded field. We "squash" the fields down
+ // if specified in the tag.
+ squash := false
+ for _, tag := range tagParts[1:] {
+ if tag == "squash" {
+ squash = true
+ break
+ }
+ }
+
+ if squash {
+ structs = append(
+ structs, result.FieldByName(fieldType.Name))
+ continue
+ }
+ }
+
+ // Normal struct field, store it away
+ fields = append(fields, field{fieldType, structVal.Field(i)})
+ }
+ }
+
+ usedKeys := make(map[string]struct{})
+ decodedFields := make([]string, 0, len(fields))
+ decodedFieldsVal := make([]reflect.Value, 0)
+ unusedKeysVal := make([]reflect.Value, 0)
+ for _, f := range fields {
+ field, fieldValue := f.field, f.val
+ if !fieldValue.IsValid() {
+ // This should never happen
+ panic("field is not valid")
+ }
+
+ // If we can't set the field, then it is unexported or something,
+ // and we just continue onwards.
+ if !fieldValue.CanSet() {
+ continue
+ }
+
+ fieldName := field.Name
+
+ tagValue := field.Tag.Get(tagName)
+ tagParts := strings.SplitN(tagValue, ",", 2)
+ if len(tagParts) >= 2 {
+ switch tagParts[1] {
+ case "decodedFields":
+ decodedFieldsVal = append(decodedFieldsVal, fieldValue)
+ continue
+ case "key":
+ if item == nil {
+ return &parser.PosError{
+ Pos: node.Pos(),
+ Err: fmt.Errorf("%s: %s asked for 'key', impossible",
+ name, fieldName),
+ }
+ }
+
+ fieldValue.SetString(item.Keys[0].Token.Value().(string))
+ continue
+ case "unusedKeys":
+ unusedKeysVal = append(unusedKeysVal, fieldValue)
+ continue
+ }
+ }
+
+ if tagParts[0] != "" {
+ fieldName = tagParts[0]
+ }
+
+ // Determine the element we'll use to decode. If it is a single
+ // match (only object with the field), then we decode it exactly.
+ // If it is a prefix match, then we decode the matches.
+ filter := list.Filter(fieldName)
+
+ prefixMatches := filter.Children()
+ matches := filter.Elem()
+ if len(matches.Items) == 0 && len(prefixMatches.Items) == 0 {
+ continue
+ }
+
+ // Track the used key
+ usedKeys[fieldName] = struct{}{}
+
+ // Create the field name and decode. We range over the elements
+ // because we actually want the value.
+ fieldName = fmt.Sprintf("%s.%s", name, fieldName)
+ if len(prefixMatches.Items) > 0 {
+ if err := d.decode(fieldName, prefixMatches, fieldValue); err != nil {
+ return err
+ }
+ }
+ for _, match := range matches.Items {
+ var decodeNode ast.Node = match.Val
+ if ot, ok := decodeNode.(*ast.ObjectType); ok {
+ decodeNode = &ast.ObjectList{Items: ot.List.Items}
+ }
+
+ if err := d.decode(fieldName, decodeNode, fieldValue); err != nil {
+ return err
+ }
+ }
+
+ decodedFields = append(decodedFields, field.Name)
+ }
+
+ if len(decodedFieldsVal) > 0 {
+ // Sort it so that it is deterministic
+ sort.Strings(decodedFields)
+
+ for _, v := range decodedFieldsVal {
+ v.Set(reflect.ValueOf(decodedFields))
+ }
+ }
+
+ return nil
+}
+
+// findNodeType returns the type of ast.Node
+func findNodeType() reflect.Type {
+ var nodeContainer struct {
+ Node ast.Node
+ }
+ value := reflect.ValueOf(nodeContainer).FieldByName("Node")
+ return value.Type()
+}
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