typesutil: support alias

Author: visualfc

internal/typesutil/alias_go121.go

@@ -5,6 +5,8 @@ package typesutil
 
 import "go/types"
 
+const SupportAlias = false
+
 type Alias struct {
 }
 

internal/typesutil/alias_go122.go

@@ -5,6 +5,8 @@ package typesutil
 
 import "go/types"
 
+const SupportAlias = true
+
 type Alias = types.Alias
 
 func NewAlias(obj *types.TypeName, rhs types.Type) *Alias {

package_test.go

@@ -3821,7 +3821,10 @@ func TestTypeAliasInFunc(t *testing.T) {
 	foo := cb.NewType("foo").InitType(pkg, typ)
 	cb.AliasType("bar", typ)
 	a := cb.AliasType("a", foo)
-	cb.AliasType("b", a)
+	alias := cb.AliasType("b", a)
+	if _, ok := alias.(*types.Named); ok {
+		t.Fatal("no named")
+	}
 	cb.End()
 	domTest(t, pkg, `package main
 

type_var_and_const.go

@@ -156,7 +156,7 @@ func (p *TypeDefs) AliasType(name string, typ types.Type, src ...ast.Node) types
 	if debugInstr {
 		log.Println("AliasType", name, typ)
 	}
-	if p.pkg.conf.EnableTypesalias {
+	if typesutil.SupportAlias && p.pkg.conf.EnableTypesalias {
 		return p.pkg.doNewAlias(p, getPos(src), name, typ, 1)
 	}
 	return p.pkg.doNewType(p, getPos(src), name, typ, 1).typ