1 files changed, 72 insertions, 0 deletions
diff --git a/vendor/golang.org/x/tools/internal/aliases/aliases_go122.go b/vendor/golang.org/x/tools/internal/aliases/aliases_go122.go
new file mode 100644
index 000000000..8b9211628
--- /dev/null
+++ b/vendor/golang.org/x/tools/internal/aliases/aliases_go122.go
@@ -0,0 +1,72 @@
+// Copyright 2024 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build go1.22
+// +build go1.22
+
+package aliases
+
+import (
+	"go/ast"
+	"go/parser"
+	"go/token"
+	"go/types"
+	"os"
+	"strings"
+	"sync"
+)
+
+// Alias is an alias of types.Alias.
+type Alias = types.Alias
+
+// Unalias is a wrapper of types.Unalias.
+func Unalias(t types.Type) types.Type { return types.Unalias(t) }
+
+// newAlias is an internal alias around types.NewAlias.
+// Direct usage is discouraged as the moment.
+// Try to use NewAlias instead.
+func newAlias(tname *types.TypeName, rhs types.Type) *Alias {
+	a := types.NewAlias(tname, rhs)
+	// TODO(go.dev/issue/65455): Remove kludgy workaround to set a.actual as a side-effect.
+	Unalias(a)
+	return a
+}
+
+// enabled returns true when types.Aliases are enabled.
+func enabled() bool {
+	// Use the gotypesalias value in GODEBUG if set.
+	godebug := os.Getenv("GODEBUG")
+	value := -1 // last set value.
+	for _, f := range strings.Split(godebug, ",") {
+		switch f {
+		case "gotypesalias=1":
+			value = 1
+		case "gotypesalias=0":
+			value = 0
+		}
+	}
+	switch value {
+	case 0:
+		return false
+	case 1:
+		return true
+	default:
+		return aliasesDefault()
+	}
+}
+
+// aliasesDefault reports if aliases are enabled by default.
+func aliasesDefault() bool {
+	// Dynamically check if Aliases will be produced from go/types.
+	aliasesDefaultOnce.Do(func() {
+		fset := token.NewFileSet()
+		f, _ := parser.ParseFile(fset, "a.go", "package p; type A = int", 0)
+		pkg, _ := new(types.Config).Check("p", fset, []*ast.File{f}, nil)
+		_, gotypesaliasDefault = pkg.Scope().Lookup("A").Type().(*types.Alias)
+	})
+	return gotypesaliasDefault
+}
+
+var gotypesaliasDefault bool
+var aliasesDefaultOnce sync.Once