diff options
Diffstat (limited to 'src/go/types/methodset.go')
| -rw-r--r-- | src/go/types/methodset.go | 52 |
1 files changed, 25 insertions, 27 deletions
diff --git a/src/go/types/methodset.go b/src/go/types/methodset.go index b27f2dac34..4f791d9d51 100644 --- a/src/go/types/methodset.go +++ b/src/go/types/methodset.go @@ -72,24 +72,22 @@ func NewMethodSet(T Type) *MethodSet { var base methodSet typ, isPtr := deref(T) - named, _ := typ.(*Named) // *typ where typ is an interface has no methods. - if isPtr { - utyp := typ - if named != nil { - utyp = named.underlying - } - if _, ok := utyp.(*Interface); ok { - return &emptyMethodSet - } + if isPtr && IsInterface(typ) { + return &emptyMethodSet } // Start with typ as single entry at shallowest depth. - // If typ is not a named type, insert a nil type instead. - current := []embeddedType{{named, nil, isPtr, false}} - - // named types that we have seen already, allocated lazily + current := []embeddedType{{typ, nil, isPtr, false}} + + // Named types that we have seen already, allocated lazily. + // Used to avoid endless searches in case of recursive types. + // Since only Named types can be used for recursive types, we + // only need to track those. + // (If we ever allow type aliases to construct recursive types, + // we must use type identity rather than pointer equality for + // the map key comparison, as we do in consolidateMultiples.) var seen map[*Named]bool // collect methods at current depth @@ -101,11 +99,12 @@ func NewMethodSet(T Type) *MethodSet { var mset methodSet for _, e := range current { - // The very first time only, e.typ may be nil. - // In this case, we don't have a named type and - // we simply continue with the underlying type. - if e.typ != nil { - if seen[e.typ] { + typ := e.typ + + // If we have a named type, we may have associated methods. + // Look for those first. + if named, _ := typ.(*Named); named != nil { + if seen[named] { // We have seen this type before, at a more shallow depth // (note that multiples of this type at the current depth // were consolidated before). The type at that depth shadows @@ -116,12 +115,12 @@ func NewMethodSet(T Type) *MethodSet { if seen == nil { seen = make(map[*Named]bool) } - seen[e.typ] = true + seen[named] = true - mset = mset.add(e.typ.methods, e.index, e.indirect, e.multiples) + mset = mset.add(named.methods, e.index, e.indirect, e.multiples) // continue with underlying type - typ = e.typ.underlying + typ = named.underlying } switch t := typ.(type) { @@ -130,16 +129,15 @@ func NewMethodSet(T Type) *MethodSet { fset = fset.add(f, e.multiples) // Embedded fields are always of the form T or *T where - // T is a named type. If typ appeared multiple times at + // T is a type name. If typ appeared multiple times at // this depth, f.Type appears multiple times at the next // depth. if f.anonymous { - // Ignore embedded basic types - only user-defined - // named types can have methods or struct fields. typ, isPtr := deref(f.typ) - if t, _ := typ.(*Named); t != nil { - next = append(next, embeddedType{t, concat(e.index, i), e.indirect || isPtr, e.multiples}) - } + // TODO(gri) optimization: ignore types that can't + // have fields or methods (only Named, Struct, and + // Interface types need to be considered). + next = append(next, embeddedType{typ, concat(e.index, i), e.indirect || isPtr, e.multiples}) } } |