blob: df36e3a30f55508515759037e072f79fc9e9e969 [file] [log] [blame]
kesavandb9f54fd2021-11-25 20:08:04 +05301//
2// Copyright (c) 2011-2019 Canonical Ltd
3//
4// Licensed under the Apache License, Version 2.0 (the "License");
5// you may not use this file except in compliance with the License.
6// You may obtain a copy of the License at
7//
8// http://www.apache.org/licenses/LICENSE-2.0
9//
10// Unless required by applicable law or agreed to in writing, software
11// distributed under the License is distributed on an "AS IS" BASIS,
12// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13// See the License for the specific language governing permissions and
14// limitations under the License.
15
16package yaml
17
18import (
19 "encoding"
20 "encoding/base64"
21 "fmt"
22 "io"
23 "math"
24 "reflect"
25 "strconv"
26 "time"
27)
28
29// ----------------------------------------------------------------------------
30// Parser, produces a node tree out of a libyaml event stream.
31
32type parser struct {
33 parser yaml_parser_t
34 event yaml_event_t
35 doc *Node
36 anchors map[string]*Node
37 doneInit bool
38 textless bool
39}
40
41func newParser(b []byte) *parser {
42 p := parser{}
43 if !yaml_parser_initialize(&p.parser) {
44 panic("failed to initialize YAML emitter")
45 }
46 if len(b) == 0 {
47 b = []byte{'\n'}
48 }
49 yaml_parser_set_input_string(&p.parser, b)
50 return &p
51}
52
53func newParserFromReader(r io.Reader) *parser {
54 p := parser{}
55 if !yaml_parser_initialize(&p.parser) {
56 panic("failed to initialize YAML emitter")
57 }
58 yaml_parser_set_input_reader(&p.parser, r)
59 return &p
60}
61
62func (p *parser) init() {
63 if p.doneInit {
64 return
65 }
66 p.anchors = make(map[string]*Node)
67 p.expect(yaml_STREAM_START_EVENT)
68 p.doneInit = true
69}
70
71func (p *parser) destroy() {
72 if p.event.typ != yaml_NO_EVENT {
73 yaml_event_delete(&p.event)
74 }
75 yaml_parser_delete(&p.parser)
76}
77
78// expect consumes an event from the event stream and
79// checks that it's of the expected type.
80func (p *parser) expect(e yaml_event_type_t) {
81 if p.event.typ == yaml_NO_EVENT {
82 if !yaml_parser_parse(&p.parser, &p.event) {
83 p.fail()
84 }
85 }
86 if p.event.typ == yaml_STREAM_END_EVENT {
87 failf("attempted to go past the end of stream; corrupted value?")
88 }
89 if p.event.typ != e {
90 p.parser.problem = fmt.Sprintf("expected %s event but got %s", e, p.event.typ)
91 p.fail()
92 }
93 yaml_event_delete(&p.event)
94 p.event.typ = yaml_NO_EVENT
95}
96
97// peek peeks at the next event in the event stream,
98// puts the results into p.event and returns the event type.
99func (p *parser) peek() yaml_event_type_t {
100 if p.event.typ != yaml_NO_EVENT {
101 return p.event.typ
102 }
103 if !yaml_parser_parse(&p.parser, &p.event) {
104 p.fail()
105 }
106 return p.event.typ
107}
108
109func (p *parser) fail() {
110 var where string
111 var line int
112 if p.parser.context_mark.line != 0 {
113 line = p.parser.context_mark.line
114 // Scanner errors don't iterate line before returning error
115 if p.parser.error == yaml_SCANNER_ERROR {
116 line++
117 }
118 } else if p.parser.problem_mark.line != 0 {
119 line = p.parser.problem_mark.line
120 // Scanner errors don't iterate line before returning error
121 if p.parser.error == yaml_SCANNER_ERROR {
122 line++
123 }
124 }
125 if line != 0 {
126 where = "line " + strconv.Itoa(line) + ": "
127 }
128 var msg string
129 if len(p.parser.problem) > 0 {
130 msg = p.parser.problem
131 } else {
132 msg = "unknown problem parsing YAML content"
133 }
134 failf("%s%s", where, msg)
135}
136
137func (p *parser) anchor(n *Node, anchor []byte) {
138 if anchor != nil {
139 n.Anchor = string(anchor)
140 p.anchors[n.Anchor] = n
141 }
142}
143
144func (p *parser) parse() *Node {
145 p.init()
146 switch p.peek() {
147 case yaml_SCALAR_EVENT:
148 return p.scalar()
149 case yaml_ALIAS_EVENT:
150 return p.alias()
151 case yaml_MAPPING_START_EVENT:
152 return p.mapping()
153 case yaml_SEQUENCE_START_EVENT:
154 return p.sequence()
155 case yaml_DOCUMENT_START_EVENT:
156 return p.document()
157 case yaml_STREAM_END_EVENT:
158 // Happens when attempting to decode an empty buffer.
159 return nil
160 case yaml_TAIL_COMMENT_EVENT:
161 panic("internal error: unexpected tail comment event (please report)")
162 default:
163 panic("internal error: attempted to parse unknown event (please report): " + p.event.typ.String())
164 }
165}
166
167func (p *parser) node(kind Kind, defaultTag, tag, value string) *Node {
168 var style Style
169 if tag != "" && tag != "!" {
170 tag = shortTag(tag)
171 style = TaggedStyle
172 } else if defaultTag != "" {
173 tag = defaultTag
174 } else if kind == ScalarNode {
175 tag, _ = resolve("", value)
176 }
177 n := &Node{
178 Kind: kind,
179 Tag: tag,
180 Value: value,
181 Style: style,
182 }
183 if !p.textless {
184 n.Line = p.event.start_mark.line + 1
185 n.Column = p.event.start_mark.column + 1
186 n.HeadComment = string(p.event.head_comment)
187 n.LineComment = string(p.event.line_comment)
188 n.FootComment = string(p.event.foot_comment)
189 }
190 return n
191}
192
193func (p *parser) parseChild(parent *Node) *Node {
194 child := p.parse()
195 parent.Content = append(parent.Content, child)
196 return child
197}
198
199func (p *parser) document() *Node {
200 n := p.node(DocumentNode, "", "", "")
201 p.doc = n
202 p.expect(yaml_DOCUMENT_START_EVENT)
203 p.parseChild(n)
204 if p.peek() == yaml_DOCUMENT_END_EVENT {
205 n.FootComment = string(p.event.foot_comment)
206 }
207 p.expect(yaml_DOCUMENT_END_EVENT)
208 return n
209}
210
211func (p *parser) alias() *Node {
212 n := p.node(AliasNode, "", "", string(p.event.anchor))
213 n.Alias = p.anchors[n.Value]
214 if n.Alias == nil {
215 failf("unknown anchor '%s' referenced", n.Value)
216 }
217 p.expect(yaml_ALIAS_EVENT)
218 return n
219}
220
221func (p *parser) scalar() *Node {
222 var parsedStyle = p.event.scalar_style()
223 var nodeStyle Style
224 switch {
225 case parsedStyle&yaml_DOUBLE_QUOTED_SCALAR_STYLE != 0:
226 nodeStyle = DoubleQuotedStyle
227 case parsedStyle&yaml_SINGLE_QUOTED_SCALAR_STYLE != 0:
228 nodeStyle = SingleQuotedStyle
229 case parsedStyle&yaml_LITERAL_SCALAR_STYLE != 0:
230 nodeStyle = LiteralStyle
231 case parsedStyle&yaml_FOLDED_SCALAR_STYLE != 0:
232 nodeStyle = FoldedStyle
233 }
234 var nodeValue = string(p.event.value)
235 var nodeTag = string(p.event.tag)
236 var defaultTag string
237 if nodeStyle == 0 {
238 if nodeValue == "<<" {
239 defaultTag = mergeTag
240 }
241 } else {
242 defaultTag = strTag
243 }
244 n := p.node(ScalarNode, defaultTag, nodeTag, nodeValue)
245 n.Style |= nodeStyle
246 p.anchor(n, p.event.anchor)
247 p.expect(yaml_SCALAR_EVENT)
248 return n
249}
250
251func (p *parser) sequence() *Node {
252 n := p.node(SequenceNode, seqTag, string(p.event.tag), "")
253 if p.event.sequence_style()&yaml_FLOW_SEQUENCE_STYLE != 0 {
254 n.Style |= FlowStyle
255 }
256 p.anchor(n, p.event.anchor)
257 p.expect(yaml_SEQUENCE_START_EVENT)
258 for p.peek() != yaml_SEQUENCE_END_EVENT {
259 p.parseChild(n)
260 }
261 n.LineComment = string(p.event.line_comment)
262 n.FootComment = string(p.event.foot_comment)
263 p.expect(yaml_SEQUENCE_END_EVENT)
264 return n
265}
266
267func (p *parser) mapping() *Node {
268 n := p.node(MappingNode, mapTag, string(p.event.tag), "")
269 block := true
270 if p.event.mapping_style()&yaml_FLOW_MAPPING_STYLE != 0 {
271 block = false
272 n.Style |= FlowStyle
273 }
274 p.anchor(n, p.event.anchor)
275 p.expect(yaml_MAPPING_START_EVENT)
276 for p.peek() != yaml_MAPPING_END_EVENT {
277 k := p.parseChild(n)
278 if block && k.FootComment != "" {
279 // Must be a foot comment for the prior value when being dedented.
280 if len(n.Content) > 2 {
281 n.Content[len(n.Content)-3].FootComment = k.FootComment
282 k.FootComment = ""
283 }
284 }
285 v := p.parseChild(n)
286 if k.FootComment == "" && v.FootComment != "" {
287 k.FootComment = v.FootComment
288 v.FootComment = ""
289 }
290 if p.peek() == yaml_TAIL_COMMENT_EVENT {
291 if k.FootComment == "" {
292 k.FootComment = string(p.event.foot_comment)
293 }
294 p.expect(yaml_TAIL_COMMENT_EVENT)
295 }
296 }
297 n.LineComment = string(p.event.line_comment)
298 n.FootComment = string(p.event.foot_comment)
299 if n.Style&FlowStyle == 0 && n.FootComment != "" && len(n.Content) > 1 {
300 n.Content[len(n.Content)-2].FootComment = n.FootComment
301 n.FootComment = ""
302 }
303 p.expect(yaml_MAPPING_END_EVENT)
304 return n
305}
306
307// ----------------------------------------------------------------------------
308// Decoder, unmarshals a node into a provided value.
309
310type decoder struct {
311 doc *Node
312 aliases map[*Node]bool
313 terrors []string
314
315 stringMapType reflect.Type
316 generalMapType reflect.Type
317
318 knownFields bool
319 uniqueKeys bool
320 decodeCount int
321 aliasCount int
322 aliasDepth int
323}
324
325var (
326 nodeType = reflect.TypeOf(Node{})
327 durationType = reflect.TypeOf(time.Duration(0))
328 stringMapType = reflect.TypeOf(map[string]interface{}{})
329 generalMapType = reflect.TypeOf(map[interface{}]interface{}{})
330 ifaceType = generalMapType.Elem()
331 timeType = reflect.TypeOf(time.Time{})
332 ptrTimeType = reflect.TypeOf(&time.Time{})
333)
334
335func newDecoder() *decoder {
336 d := &decoder{
337 stringMapType: stringMapType,
338 generalMapType: generalMapType,
339 uniqueKeys: true,
340 }
341 d.aliases = make(map[*Node]bool)
342 return d
343}
344
345func (d *decoder) terror(n *Node, tag string, out reflect.Value) {
346 if n.Tag != "" {
347 tag = n.Tag
348 }
349 value := n.Value
350 if tag != seqTag && tag != mapTag {
351 if len(value) > 10 {
352 value = " `" + value[:7] + "...`"
353 } else {
354 value = " `" + value + "`"
355 }
356 }
357 d.terrors = append(d.terrors, fmt.Sprintf("line %d: cannot unmarshal %s%s into %s", n.Line, shortTag(tag), value, out.Type()))
358}
359
360func (d *decoder) callUnmarshaler(n *Node, u Unmarshaler) (good bool) {
361 err := u.UnmarshalYAML(n)
362 if e, ok := err.(*TypeError); ok {
363 d.terrors = append(d.terrors, e.Errors...)
364 return false
365 }
366 if err != nil {
367 fail(err)
368 }
369 return true
370}
371
372func (d *decoder) callObsoleteUnmarshaler(n *Node, u obsoleteUnmarshaler) (good bool) {
373 terrlen := len(d.terrors)
374 err := u.UnmarshalYAML(func(v interface{}) (err error) {
375 defer handleErr(&err)
376 d.unmarshal(n, reflect.ValueOf(v))
377 if len(d.terrors) > terrlen {
378 issues := d.terrors[terrlen:]
379 d.terrors = d.terrors[:terrlen]
380 return &TypeError{issues}
381 }
382 return nil
383 })
384 if e, ok := err.(*TypeError); ok {
385 d.terrors = append(d.terrors, e.Errors...)
386 return false
387 }
388 if err != nil {
389 fail(err)
390 }
391 return true
392}
393
394// d.prepare initializes and dereferences pointers and calls UnmarshalYAML
395// if a value is found to implement it.
396// It returns the initialized and dereferenced out value, whether
397// unmarshalling was already done by UnmarshalYAML, and if so whether
398// its types unmarshalled appropriately.
399//
400// If n holds a null value, prepare returns before doing anything.
401func (d *decoder) prepare(n *Node, out reflect.Value) (newout reflect.Value, unmarshaled, good bool) {
402 if n.ShortTag() == nullTag {
403 return out, false, false
404 }
405 again := true
406 for again {
407 again = false
408 if out.Kind() == reflect.Ptr {
409 if out.IsNil() {
410 out.Set(reflect.New(out.Type().Elem()))
411 }
412 out = out.Elem()
413 again = true
414 }
415 if out.CanAddr() {
416 outi := out.Addr().Interface()
417 if u, ok := outi.(Unmarshaler); ok {
418 good = d.callUnmarshaler(n, u)
419 return out, true, good
420 }
421 if u, ok := outi.(obsoleteUnmarshaler); ok {
422 good = d.callObsoleteUnmarshaler(n, u)
423 return out, true, good
424 }
425 }
426 }
427 return out, false, false
428}
429
430func (d *decoder) fieldByIndex(n *Node, v reflect.Value, index []int) (field reflect.Value) {
431 if n.ShortTag() == nullTag {
432 return reflect.Value{}
433 }
434 for _, num := range index {
435 for {
436 if v.Kind() == reflect.Ptr {
437 if v.IsNil() {
438 v.Set(reflect.New(v.Type().Elem()))
439 }
440 v = v.Elem()
441 continue
442 }
443 break
444 }
445 v = v.Field(num)
446 }
447 return v
448}
449
450const (
451 // 400,000 decode operations is ~500kb of dense object declarations, or
452 // ~5kb of dense object declarations with 10000% alias expansion
453 alias_ratio_range_low = 400000
454
455 // 4,000,000 decode operations is ~5MB of dense object declarations, or
456 // ~4.5MB of dense object declarations with 10% alias expansion
457 alias_ratio_range_high = 4000000
458
459 // alias_ratio_range is the range over which we scale allowed alias ratios
460 alias_ratio_range = float64(alias_ratio_range_high - alias_ratio_range_low)
461)
462
463func allowedAliasRatio(decodeCount int) float64 {
464 switch {
465 case decodeCount <= alias_ratio_range_low:
466 // allow 99% to come from alias expansion for small-to-medium documents
467 return 0.99
468 case decodeCount >= alias_ratio_range_high:
469 // allow 10% to come from alias expansion for very large documents
470 return 0.10
471 default:
472 // scale smoothly from 99% down to 10% over the range.
473 // this maps to 396,000 - 400,000 allowed alias-driven decodes over the range.
474 // 400,000 decode operations is ~100MB of allocations in worst-case scenarios (single-item maps).
475 return 0.99 - 0.89*(float64(decodeCount-alias_ratio_range_low)/alias_ratio_range)
476 }
477}
478
479func (d *decoder) unmarshal(n *Node, out reflect.Value) (good bool) {
480 d.decodeCount++
481 if d.aliasDepth > 0 {
482 d.aliasCount++
483 }
484 if d.aliasCount > 100 && d.decodeCount > 1000 && float64(d.aliasCount)/float64(d.decodeCount) > allowedAliasRatio(d.decodeCount) {
485 failf("document contains excessive aliasing")
486 }
487 if out.Type() == nodeType {
488 out.Set(reflect.ValueOf(n).Elem())
489 return true
490 }
491 switch n.Kind {
492 case DocumentNode:
493 return d.document(n, out)
494 case AliasNode:
495 return d.alias(n, out)
496 }
497 out, unmarshaled, good := d.prepare(n, out)
498 if unmarshaled {
499 return good
500 }
501 switch n.Kind {
502 case ScalarNode:
503 good = d.scalar(n, out)
504 case MappingNode:
505 good = d.mapping(n, out)
506 case SequenceNode:
507 good = d.sequence(n, out)
508 case 0:
509 if n.IsZero() {
510 return d.null(out)
511 }
512 fallthrough
513 default:
514 failf("cannot decode node with unknown kind %d", n.Kind)
515 }
516 return good
517}
518
519func (d *decoder) document(n *Node, out reflect.Value) (good bool) {
520 if len(n.Content) == 1 {
521 d.doc = n
522 d.unmarshal(n.Content[0], out)
523 return true
524 }
525 return false
526}
527
528func (d *decoder) alias(n *Node, out reflect.Value) (good bool) {
529 if d.aliases[n] {
530 // TODO this could actually be allowed in some circumstances.
531 failf("anchor '%s' value contains itself", n.Value)
532 }
533 d.aliases[n] = true
534 d.aliasDepth++
535 good = d.unmarshal(n.Alias, out)
536 d.aliasDepth--
537 delete(d.aliases, n)
538 return good
539}
540
541var zeroValue reflect.Value
542
543func resetMap(out reflect.Value) {
544 for _, k := range out.MapKeys() {
545 out.SetMapIndex(k, zeroValue)
546 }
547}
548
549func (d *decoder) null(out reflect.Value) bool {
550 if out.CanAddr() {
551 switch out.Kind() {
552 case reflect.Interface, reflect.Ptr, reflect.Map, reflect.Slice:
553 out.Set(reflect.Zero(out.Type()))
554 return true
555 }
556 }
557 return false
558}
559
560func (d *decoder) scalar(n *Node, out reflect.Value) bool {
561 var tag string
562 var resolved interface{}
563 if n.indicatedString() {
564 tag = strTag
565 resolved = n.Value
566 } else {
567 tag, resolved = resolve(n.Tag, n.Value)
568 if tag == binaryTag {
569 data, err := base64.StdEncoding.DecodeString(resolved.(string))
570 if err != nil {
571 failf("!!binary value contains invalid base64 data")
572 }
573 resolved = string(data)
574 }
575 }
576 if resolved == nil {
577 return d.null(out)
578 }
579 if resolvedv := reflect.ValueOf(resolved); out.Type() == resolvedv.Type() {
580 // We've resolved to exactly the type we want, so use that.
581 out.Set(resolvedv)
582 return true
583 }
584 // Perhaps we can use the value as a TextUnmarshaler to
585 // set its value.
586 if out.CanAddr() {
587 u, ok := out.Addr().Interface().(encoding.TextUnmarshaler)
588 if ok {
589 var text []byte
590 if tag == binaryTag {
591 text = []byte(resolved.(string))
592 } else {
593 // We let any value be unmarshaled into TextUnmarshaler.
594 // That might be more lax than we'd like, but the
595 // TextUnmarshaler itself should bowl out any dubious values.
596 text = []byte(n.Value)
597 }
598 err := u.UnmarshalText(text)
599 if err != nil {
600 fail(err)
601 }
602 return true
603 }
604 }
605 switch out.Kind() {
606 case reflect.String:
607 if tag == binaryTag {
608 out.SetString(resolved.(string))
609 return true
610 }
611 out.SetString(n.Value)
612 return true
613 case reflect.Interface:
614 out.Set(reflect.ValueOf(resolved))
615 return true
616 case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
617 // This used to work in v2, but it's very unfriendly.
618 isDuration := out.Type() == durationType
619
620 switch resolved := resolved.(type) {
621 case int:
622 if !isDuration && !out.OverflowInt(int64(resolved)) {
623 out.SetInt(int64(resolved))
624 return true
625 }
626 case int64:
627 if !isDuration && !out.OverflowInt(resolved) {
628 out.SetInt(resolved)
629 return true
630 }
631 case uint64:
632 if !isDuration && resolved <= math.MaxInt64 && !out.OverflowInt(int64(resolved)) {
633 out.SetInt(int64(resolved))
634 return true
635 }
636 case float64:
637 if !isDuration && resolved <= math.MaxInt64 && !out.OverflowInt(int64(resolved)) {
638 out.SetInt(int64(resolved))
639 return true
640 }
641 case string:
642 if out.Type() == durationType {
643 d, err := time.ParseDuration(resolved)
644 if err == nil {
645 out.SetInt(int64(d))
646 return true
647 }
648 }
649 }
650 case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
651 switch resolved := resolved.(type) {
652 case int:
653 if resolved >= 0 && !out.OverflowUint(uint64(resolved)) {
654 out.SetUint(uint64(resolved))
655 return true
656 }
657 case int64:
658 if resolved >= 0 && !out.OverflowUint(uint64(resolved)) {
659 out.SetUint(uint64(resolved))
660 return true
661 }
662 case uint64:
663 if !out.OverflowUint(uint64(resolved)) {
664 out.SetUint(uint64(resolved))
665 return true
666 }
667 case float64:
668 if resolved <= math.MaxUint64 && !out.OverflowUint(uint64(resolved)) {
669 out.SetUint(uint64(resolved))
670 return true
671 }
672 }
673 case reflect.Bool:
674 switch resolved := resolved.(type) {
675 case bool:
676 out.SetBool(resolved)
677 return true
678 case string:
679 // This offers some compatibility with the 1.1 spec (https://yaml.org/type/bool.html).
680 // It only works if explicitly attempting to unmarshal into a typed bool value.
681 switch resolved {
682 case "y", "Y", "yes", "Yes", "YES", "on", "On", "ON":
683 out.SetBool(true)
684 return true
685 case "n", "N", "no", "No", "NO", "off", "Off", "OFF":
686 out.SetBool(false)
687 return true
688 }
689 }
690 case reflect.Float32, reflect.Float64:
691 switch resolved := resolved.(type) {
692 case int:
693 out.SetFloat(float64(resolved))
694 return true
695 case int64:
696 out.SetFloat(float64(resolved))
697 return true
698 case uint64:
699 out.SetFloat(float64(resolved))
700 return true
701 case float64:
702 out.SetFloat(resolved)
703 return true
704 }
705 case reflect.Struct:
706 if resolvedv := reflect.ValueOf(resolved); out.Type() == resolvedv.Type() {
707 out.Set(resolvedv)
708 return true
709 }
710 case reflect.Ptr:
711 panic("yaml internal error: please report the issue")
712 }
713 d.terror(n, tag, out)
714 return false
715}
716
717func settableValueOf(i interface{}) reflect.Value {
718 v := reflect.ValueOf(i)
719 sv := reflect.New(v.Type()).Elem()
720 sv.Set(v)
721 return sv
722}
723
724func (d *decoder) sequence(n *Node, out reflect.Value) (good bool) {
725 l := len(n.Content)
726
727 var iface reflect.Value
728 switch out.Kind() {
729 case reflect.Slice:
730 out.Set(reflect.MakeSlice(out.Type(), l, l))
731 case reflect.Array:
732 if l != out.Len() {
733 failf("invalid array: want %d elements but got %d", out.Len(), l)
734 }
735 case reflect.Interface:
736 // No type hints. Will have to use a generic sequence.
737 iface = out
738 out = settableValueOf(make([]interface{}, l))
739 default:
740 d.terror(n, seqTag, out)
741 return false
742 }
743 et := out.Type().Elem()
744
745 j := 0
746 for i := 0; i < l; i++ {
747 e := reflect.New(et).Elem()
748 if ok := d.unmarshal(n.Content[i], e); ok {
749 out.Index(j).Set(e)
750 j++
751 }
752 }
753 if out.Kind() != reflect.Array {
754 out.Set(out.Slice(0, j))
755 }
756 if iface.IsValid() {
757 iface.Set(out)
758 }
759 return true
760}
761
762func (d *decoder) mapping(n *Node, out reflect.Value) (good bool) {
763 l := len(n.Content)
764 if d.uniqueKeys {
765 nerrs := len(d.terrors)
766 for i := 0; i < l; i += 2 {
767 ni := n.Content[i]
768 for j := i + 2; j < l; j += 2 {
769 nj := n.Content[j]
770 if ni.Kind == nj.Kind && ni.Value == nj.Value {
771 d.terrors = append(d.terrors, fmt.Sprintf("line %d: mapping key %#v already defined at line %d", nj.Line, nj.Value, ni.Line))
772 }
773 }
774 }
775 if len(d.terrors) > nerrs {
776 return false
777 }
778 }
779 switch out.Kind() {
780 case reflect.Struct:
781 return d.mappingStruct(n, out)
782 case reflect.Map:
783 // okay
784 case reflect.Interface:
785 iface := out
786 if isStringMap(n) {
787 out = reflect.MakeMap(d.stringMapType)
788 } else {
789 out = reflect.MakeMap(d.generalMapType)
790 }
791 iface.Set(out)
792 default:
793 d.terror(n, mapTag, out)
794 return false
795 }
796
797 outt := out.Type()
798 kt := outt.Key()
799 et := outt.Elem()
800
801 stringMapType := d.stringMapType
802 generalMapType := d.generalMapType
803 if outt.Elem() == ifaceType {
804 if outt.Key().Kind() == reflect.String {
805 d.stringMapType = outt
806 } else if outt.Key() == ifaceType {
807 d.generalMapType = outt
808 }
809 }
810
811 mapIsNew := false
812 if out.IsNil() {
813 out.Set(reflect.MakeMap(outt))
814 mapIsNew = true
815 }
816 for i := 0; i < l; i += 2 {
817 if isMerge(n.Content[i]) {
818 d.merge(n.Content[i+1], out)
819 continue
820 }
821 k := reflect.New(kt).Elem()
822 if d.unmarshal(n.Content[i], k) {
823 kkind := k.Kind()
824 if kkind == reflect.Interface {
825 kkind = k.Elem().Kind()
826 }
827 if kkind == reflect.Map || kkind == reflect.Slice {
828 failf("invalid map key: %#v", k.Interface())
829 }
830 e := reflect.New(et).Elem()
831 if d.unmarshal(n.Content[i+1], e) || n.Content[i+1].ShortTag() == nullTag && (mapIsNew || !out.MapIndex(k).IsValid()) {
832 out.SetMapIndex(k, e)
833 }
834 }
835 }
836 d.stringMapType = stringMapType
837 d.generalMapType = generalMapType
838 return true
839}
840
841func isStringMap(n *Node) bool {
842 if n.Kind != MappingNode {
843 return false
844 }
845 l := len(n.Content)
846 for i := 0; i < l; i += 2 {
847 if n.Content[i].ShortTag() != strTag {
848 return false
849 }
850 }
851 return true
852}
853
854func (d *decoder) mappingStruct(n *Node, out reflect.Value) (good bool) {
855 sinfo, err := getStructInfo(out.Type())
856 if err != nil {
857 panic(err)
858 }
859
860 var inlineMap reflect.Value
861 var elemType reflect.Type
862 if sinfo.InlineMap != -1 {
863 inlineMap = out.Field(sinfo.InlineMap)
864 inlineMap.Set(reflect.New(inlineMap.Type()).Elem())
865 elemType = inlineMap.Type().Elem()
866 }
867
868 for _, index := range sinfo.InlineUnmarshalers {
869 field := d.fieldByIndex(n, out, index)
870 d.prepare(n, field)
871 }
872
873 var doneFields []bool
874 if d.uniqueKeys {
875 doneFields = make([]bool, len(sinfo.FieldsList))
876 }
877 name := settableValueOf("")
878 l := len(n.Content)
879 for i := 0; i < l; i += 2 {
880 ni := n.Content[i]
881 if isMerge(ni) {
882 d.merge(n.Content[i+1], out)
883 continue
884 }
885 if !d.unmarshal(ni, name) {
886 continue
887 }
888 if info, ok := sinfo.FieldsMap[name.String()]; ok {
889 if d.uniqueKeys {
890 if doneFields[info.Id] {
891 d.terrors = append(d.terrors, fmt.Sprintf("line %d: field %s already set in type %s", ni.Line, name.String(), out.Type()))
892 continue
893 }
894 doneFields[info.Id] = true
895 }
896 var field reflect.Value
897 if info.Inline == nil {
898 field = out.Field(info.Num)
899 } else {
900 field = d.fieldByIndex(n, out, info.Inline)
901 }
902 d.unmarshal(n.Content[i+1], field)
903 } else if sinfo.InlineMap != -1 {
904 if inlineMap.IsNil() {
905 inlineMap.Set(reflect.MakeMap(inlineMap.Type()))
906 }
907 value := reflect.New(elemType).Elem()
908 d.unmarshal(n.Content[i+1], value)
909 inlineMap.SetMapIndex(name, value)
910 } else if d.knownFields {
911 d.terrors = append(d.terrors, fmt.Sprintf("line %d: field %s not found in type %s", ni.Line, name.String(), out.Type()))
912 }
913 }
914 return true
915}
916
917func failWantMap() {
918 failf("map merge requires map or sequence of maps as the value")
919}
920
921func (d *decoder) merge(n *Node, out reflect.Value) {
922 switch n.Kind {
923 case MappingNode:
924 d.unmarshal(n, out)
925 case AliasNode:
926 if n.Alias != nil && n.Alias.Kind != MappingNode {
927 failWantMap()
928 }
929 d.unmarshal(n, out)
930 case SequenceNode:
931 // Step backwards as earlier nodes take precedence.
932 for i := len(n.Content) - 1; i >= 0; i-- {
933 ni := n.Content[i]
934 if ni.Kind == AliasNode {
935 if ni.Alias != nil && ni.Alias.Kind != MappingNode {
936 failWantMap()
937 }
938 } else if ni.Kind != MappingNode {
939 failWantMap()
940 }
941 d.unmarshal(ni, out)
942 }
943 default:
944 failWantMap()
945 }
946}
947
948func isMerge(n *Node) bool {
949 return n.Kind == ScalarNode && n.Value == "<<" && (n.Tag == "" || n.Tag == "!" || shortTag(n.Tag) == mergeTag)
950}