diff options
Diffstat (limited to 'src/go/types/instantiate.go')
| -rw-r--r-- | src/go/types/instantiate.go | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/src/go/types/instantiate.go b/src/go/types/instantiate.go index 1d3bbc2667..28d68cad0e 100644 --- a/src/go/types/instantiate.go +++ b/src/go/types/instantiate.go @@ -105,7 +105,9 @@ func (check *Checker) instantiate(pos token.Pos, typ Type, tparams []*TypeName, // instantiating the type until needed. typ must be a *Named // type. func (check *Checker) InstantiateLazy(pos token.Pos, typ Type, targs []Type, posList []token.Pos, verify bool) Type { - base := asNamed(typ) + // Don't use asNamed here: we don't want to expand the base during lazy + // instantiation. + base := typ.(*Named) if base == nil { panic(fmt.Sprintf("%v: cannot instantiate %v", pos, typ)) } @@ -116,15 +118,18 @@ func (check *Checker) InstantiateLazy(pos token.Pos, typ Type, targs []Type, pos } h := instantiatedHash(base, targs) if check != nil { + // typ may already have been instantiated with identical type arguments. In + // that case, re-use the existing instance. if named := check.typMap[h]; named != nil { return named } } tname := NewTypeName(pos, base.obj.pkg, base.obj.name, nil) - named := check.newNamed(tname, base, nil, base.TParams(), base.methods) // methods are instantiated lazily + named := check.newNamed(tname, base, nil, nil, nil) // methods and tparams are set when named is loaded. named.targs = targs - named.instance = &instance{check, pos, posList} + named.instance = &instance{pos, posList} + if check != nil { check.typMap[h] = named } |