--- /dev/null
+// Copyright 2014 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.
+
+package typeutil
+
+import "go/types"
+
+// Dependencies returns all dependencies of the specified packages.
+//
+// Dependent packages appear in topological order: if package P imports
+// package Q, Q appears earlier than P in the result.
+// The algorithm follows import statements in the order they
+// appear in the source code, so the result is a total order.
+//
+func Dependencies(pkgs ...*types.Package) []*types.Package {
+ var result []*types.Package
+ seen := make(map[*types.Package]bool)
+ var visit func(pkgs []*types.Package)
+ visit = func(pkgs []*types.Package) {
+ for _, p := range pkgs {
+ if !seen[p] {
+ seen[p] = true
+ visit(p.Imports())
+ result = append(result, p)
+ }
+ }
+ }
+ visit(pkgs)
+ return result
+}