Source file
src/go/types/object.go
1
2
3
4
5
6
7
8 package types
9
10 import (
11 "bytes"
12 "fmt"
13 "go/constant"
14 "go/token"
15 "strings"
16 "unicode"
17 "unicode/utf8"
18 )
19
20
21
22
23
24
25
26
27
28
29 type Object interface {
30 Parent() *Scope
31 Pos() token.Pos
32 Pkg() *Package
33 Name() string
34 Type() Type
35 Exported() bool
36 Id() string
37
38
39
40 String() string
41
42
43
44
45
46 order() uint32
47
48
49 setType(Type)
50
51
52 setOrder(uint32)
53
54
55 setParent(*Scope)
56
57
58
59
60 sameId(pkg *Package, name string, foldCase bool) bool
61
62
63 scopePos() token.Pos
64
65
66 setScopePos(pos token.Pos)
67 }
68
69 func isExported(name string) bool {
70 ch, _ := utf8.DecodeRuneInString(name)
71 return unicode.IsUpper(ch)
72 }
73
74
75
76 func Id(pkg *Package, name string) string {
77 if isExported(name) {
78 return name
79 }
80
81
82
83
84
85 path := "_"
86
87
88 if pkg != nil && pkg.path != "" {
89 path = pkg.path
90 }
91 return path + "." + name
92 }
93
94
95 type object struct {
96 parent *Scope
97 pos token.Pos
98 pkg *Package
99 name string
100 typ Type
101 order_ uint32
102 scopePos_ token.Pos
103 }
104
105
106
107 func (obj *object) Parent() *Scope { return obj.parent }
108
109
110 func (obj *object) Pos() token.Pos { return obj.pos }
111
112
113
114 func (obj *object) Pkg() *Package { return obj.pkg }
115
116
117 func (obj *object) Name() string { return obj.name }
118
119
120 func (obj *object) Type() Type { return obj.typ }
121
122
123
124
125 func (obj *object) Exported() bool { return isExported(obj.name) }
126
127
128 func (obj *object) Id() string { return Id(obj.pkg, obj.name) }
129
130 func (obj *object) String() string { panic("abstract") }
131 func (obj *object) order() uint32 { return obj.order_ }
132 func (obj *object) scopePos() token.Pos { return obj.scopePos_ }
133
134 func (obj *object) setParent(parent *Scope) { obj.parent = parent }
135 func (obj *object) setType(typ Type) { obj.typ = typ }
136 func (obj *object) setOrder(order uint32) { assert(order > 0); obj.order_ = order }
137 func (obj *object) setScopePos(pos token.Pos) { obj.scopePos_ = pos }
138
139 func (obj *object) sameId(pkg *Package, name string, foldCase bool) bool {
140
141 if foldCase && strings.EqualFold(obj.name, name) {
142 return true
143 }
144
145
146
147
148 if obj.name != name {
149 return false
150 }
151
152 if obj.Exported() {
153 return true
154 }
155
156 return samePkg(obj.pkg, pkg)
157 }
158
159
160
161
162
163
164
165
166
167
168
169 func (a *object) cmp(b *object) int {
170 if a == b {
171 return 0
172 }
173
174
175 if a == nil {
176 return -1
177 }
178 if b == nil {
179 return +1
180 }
181
182
183 ea := isExported(a.name)
184 eb := isExported(b.name)
185 if ea != eb {
186 if ea {
187 return -1
188 }
189 return +1
190 }
191
192
193 if a.name != b.name {
194 return strings.Compare(a.name, b.name)
195 }
196 if !ea {
197 return strings.Compare(a.pkg.path, b.pkg.path)
198 }
199
200 return 0
201 }
202
203
204
205 type PkgName struct {
206 object
207 imported *Package
208 }
209
210
211
212 func NewPkgName(pos token.Pos, pkg *Package, name string, imported *Package) *PkgName {
213 return &PkgName{object{nil, pos, pkg, name, Typ[Invalid], 0, nopos}, imported}
214 }
215
216
217
218 func (obj *PkgName) Imported() *Package { return obj.imported }
219
220
221 type Const struct {
222 object
223 val constant.Value
224 }
225
226
227
228 func NewConst(pos token.Pos, pkg *Package, name string, typ Type, val constant.Value) *Const {
229 return &Const{object{nil, pos, pkg, name, typ, 0, nopos}, val}
230 }
231
232
233 func (obj *Const) Val() constant.Value { return obj.val }
234
235 func (*Const) isDependency() {}
236
237
238
239
240
241
242 type TypeName struct {
243 object
244 }
245
246
247
248
249
250
251
252
253 func NewTypeName(pos token.Pos, pkg *Package, name string, typ Type) *TypeName {
254 return &TypeName{object{nil, pos, pkg, name, typ, 0, nopos}}
255 }
256
257
258
259 func _NewTypeNameLazy(pos token.Pos, pkg *Package, name string, load func(*Named) ([]*TypeParam, Type, []*Func, []func())) *TypeName {
260 obj := NewTypeName(pos, pkg, name, nil)
261 n := (*Checker)(nil).newNamed(obj, nil, nil)
262 n.loader = load
263 return obj
264 }
265
266
267 func (obj *TypeName) IsAlias() bool {
268 switch t := obj.typ.(type) {
269 case nil:
270 return false
271
272
273 case *Basic:
274
275 if obj.pkg == Unsafe {
276 return false
277 }
278
279
280
281
282
283
284 return obj.pkg != nil || t.name != obj.name || t == universeByte || t == universeRune
285 case *Named:
286 return obj != t.obj
287 case *TypeParam:
288 return obj != t.obj
289 default:
290 return true
291 }
292 }
293
294
295 type Var struct {
296 object
297 origin *Var
298 kind VarKind
299 embedded bool
300 }
301
302
303 type VarKind uint8
304
305 const (
306 _ VarKind = iota
307 PackageVar
308 LocalVar
309 RecvVar
310 ParamVar
311 ResultVar
312 FieldVar
313 )
314
315 var varKindNames = [...]string{
316 0: "VarKind(0)",
317 PackageVar: "PackageVar",
318 LocalVar: "LocalVar",
319 RecvVar: "RecvVar",
320 ParamVar: "ParamVar",
321 ResultVar: "ResultVar",
322 FieldVar: "FieldVar",
323 }
324
325 func (kind VarKind) String() string {
326 if 0 <= kind && int(kind) < len(varKindNames) {
327 return varKindNames[kind]
328 }
329 return fmt.Sprintf("VarKind(%d)", kind)
330 }
331
332
333 func (v *Var) Kind() VarKind { return v.kind }
334
335
336
337 func (v *Var) SetKind(kind VarKind) { v.kind = kind }
338
339
340
341
342
343
344 func NewVar(pos token.Pos, pkg *Package, name string, typ Type) *Var {
345 return newVar(PackageVar, pos, pkg, name, typ)
346 }
347
348
349
350
351
352 func NewParam(pos token.Pos, pkg *Package, name string, typ Type) *Var {
353 return newVar(ParamVar, pos, pkg, name, typ)
354 }
355
356
357
358
359 func NewField(pos token.Pos, pkg *Package, name string, typ Type, embedded bool) *Var {
360 v := newVar(FieldVar, pos, pkg, name, typ)
361 v.embedded = embedded
362 return v
363 }
364
365
366
367 func newVar(kind VarKind, pos token.Pos, pkg *Package, name string, typ Type) *Var {
368 return &Var{object: object{nil, pos, pkg, name, typ, 0, nopos}, kind: kind}
369 }
370
371
372
373 func (obj *Var) Anonymous() bool { return obj.embedded }
374
375
376 func (obj *Var) Embedded() bool { return obj.embedded }
377
378
379 func (obj *Var) IsField() bool { return obj.kind == FieldVar }
380
381
382
383
384
385
386
387
388 func (obj *Var) Origin() *Var {
389 if obj.origin != nil {
390 return obj.origin
391 }
392 return obj
393 }
394
395 func (*Var) isDependency() {}
396
397
398
399
400 type Func struct {
401 object
402 hasPtrRecv_ bool
403 origin *Func
404 }
405
406
407
408 func NewFunc(pos token.Pos, pkg *Package, name string, sig *Signature) *Func {
409 var typ Type
410 if sig != nil {
411 typ = sig
412 } else {
413
414
415
416
417 }
418 return &Func{object{nil, pos, pkg, name, typ, 0, nopos}, false, nil}
419 }
420
421
422 func (obj *Func) Signature() *Signature {
423 if obj.typ != nil {
424 return obj.typ.(*Signature)
425 }
426
427
428
429
430
431
432
433
434 return new(Signature)
435 }
436
437
438
439 func (obj *Func) FullName() string {
440 var buf bytes.Buffer
441 writeFuncName(&buf, obj, nil)
442 return buf.String()
443 }
444
445
446
447
448 func (obj *Func) Scope() *Scope { return obj.typ.(*Signature).scope }
449
450
451
452
453
454
455
456
457 func (obj *Func) Origin() *Func {
458 if obj.origin != nil {
459 return obj.origin
460 }
461 return obj
462 }
463
464
465
466
467
468 func (obj *Func) Pkg() *Package { return obj.object.Pkg() }
469
470
471 func (obj *Func) hasPtrRecv() bool {
472
473
474
475
476 if sig, _ := obj.typ.(*Signature); sig != nil && sig.recv != nil {
477 _, isPtr := deref(sig.recv.typ)
478 return isPtr
479 }
480
481
482
483
484
485
486 return obj.hasPtrRecv_
487 }
488
489 func (*Func) isDependency() {}
490
491
492
493 type Label struct {
494 object
495 used bool
496 }
497
498
499 func NewLabel(pos token.Pos, pkg *Package, name string) *Label {
500 return &Label{object{pos: pos, pkg: pkg, name: name, typ: Typ[Invalid]}, false}
501 }
502
503
504
505 type Builtin struct {
506 object
507 id builtinId
508 }
509
510 func newBuiltin(id builtinId) *Builtin {
511 return &Builtin{object{name: predeclaredFuncs[id].name, typ: Typ[Invalid]}, id}
512 }
513
514
515 type Nil struct {
516 object
517 }
518
519 func writeObject(buf *bytes.Buffer, obj Object, qf Qualifier) {
520 var tname *TypeName
521 typ := obj.Type()
522
523 switch obj := obj.(type) {
524 case *PkgName:
525 fmt.Fprintf(buf, "package %s", obj.Name())
526 if path := obj.imported.path; path != "" && path != obj.name {
527 fmt.Fprintf(buf, " (%q)", path)
528 }
529 return
530
531 case *Const:
532 buf.WriteString("const")
533
534 case *TypeName:
535 tname = obj
536 buf.WriteString("type")
537 if isTypeParam(typ) {
538 buf.WriteString(" parameter")
539 }
540
541 case *Var:
542 if obj.IsField() {
543 buf.WriteString("field")
544 } else {
545 buf.WriteString("var")
546 }
547
548 case *Func:
549 buf.WriteString("func ")
550 writeFuncName(buf, obj, qf)
551 if typ != nil {
552 WriteSignature(buf, typ.(*Signature), qf)
553 }
554 return
555
556 case *Label:
557 buf.WriteString("label")
558 typ = nil
559
560 case *Builtin:
561 buf.WriteString("builtin")
562 typ = nil
563
564 case *Nil:
565 buf.WriteString("nil")
566 return
567
568 default:
569 panic(fmt.Sprintf("writeObject(%T)", obj))
570 }
571
572 buf.WriteByte(' ')
573
574
575 if obj.Pkg() != nil && obj.Pkg().scope.Lookup(obj.Name()) == obj {
576 buf.WriteString(packagePrefix(obj.Pkg(), qf))
577 }
578 buf.WriteString(obj.Name())
579
580 if typ == nil {
581 return
582 }
583
584 if tname != nil {
585 switch t := typ.(type) {
586 case *Basic:
587
588
589 return
590 case genericType:
591 if t.TypeParams().Len() > 0 {
592 newTypeWriter(buf, qf).tParamList(t.TypeParams().list())
593 }
594 }
595 if tname.IsAlias() {
596 buf.WriteString(" =")
597 if alias, ok := typ.(*Alias); ok {
598 typ = alias.fromRHS
599 }
600 } else if t, _ := typ.(*TypeParam); t != nil {
601 typ = t.bound
602 } else {
603
604
605 typ = typ.Underlying()
606 }
607 }
608
609
610
611
612 if obj.Name() == "any" && obj.Parent() == Universe {
613 assert(Identical(typ, &emptyInterface))
614 typ = &emptyInterface
615 }
616
617 buf.WriteByte(' ')
618 WriteType(buf, typ, qf)
619 }
620
621 func packagePrefix(pkg *Package, qf Qualifier) string {
622 if pkg == nil {
623 return ""
624 }
625 var s string
626 if qf != nil {
627 s = qf(pkg)
628 } else {
629 s = pkg.Path()
630 }
631 if s != "" {
632 s += "."
633 }
634 return s
635 }
636
637
638
639
640 func ObjectString(obj Object, qf Qualifier) string {
641 var buf bytes.Buffer
642 writeObject(&buf, obj, qf)
643 return buf.String()
644 }
645
646 func (obj *PkgName) String() string { return ObjectString(obj, nil) }
647 func (obj *Const) String() string { return ObjectString(obj, nil) }
648 func (obj *TypeName) String() string { return ObjectString(obj, nil) }
649 func (obj *Var) String() string { return ObjectString(obj, nil) }
650 func (obj *Func) String() string { return ObjectString(obj, nil) }
651 func (obj *Label) String() string { return ObjectString(obj, nil) }
652 func (obj *Builtin) String() string { return ObjectString(obj, nil) }
653 func (obj *Nil) String() string { return ObjectString(obj, nil) }
654
655 func writeFuncName(buf *bytes.Buffer, f *Func, qf Qualifier) {
656 if f.typ != nil {
657 sig := f.typ.(*Signature)
658 if recv := sig.Recv(); recv != nil {
659 buf.WriteByte('(')
660 if _, ok := recv.Type().(*Interface); ok {
661
662
663
664
665 buf.WriteString("interface")
666 } else {
667 WriteType(buf, recv.Type(), qf)
668 }
669 buf.WriteByte(')')
670 buf.WriteByte('.')
671 } else if f.pkg != nil {
672 buf.WriteString(packagePrefix(f.pkg, qf))
673 }
674 }
675 buf.WriteString(f.name)
676 }
677
View as plain text