Maintain go 1.8 compat

endtoend_test.go

@@ -33,7 +33,7 @@ func TestEndToEnd(t *testing.T) {
 	defer os.RemoveAll(dir)
 	// Create stringer in temporary directory.
 	stringer := filepath.Join(dir, "stringer.exe")
-	err = run("go", "build", "-o", stringer, "enumer.go", "sql.go", "stringer.go", "transformer.go")
+	err = run("go", "build", "-o", stringer)
 	if err != nil {
 		t.Fatalf("building stringer: %s", err)
 	}

importer18.go

@@ -0,0 +1,16 @@
+// Copyright 2017 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.
+
+// +build !go1.9
+
+package main
+
+import (
+	"go/importer"
+	"go/types"
+)
+
+func defaultImporter() types.Importer {
+	return importer.Default()
+}

importer19.go

@@ -0,0 +1,16 @@
+// Copyright 2017 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.
+
+// +build go1.9
+
+package main
+
+import (
+	"go/importer"
+	"go/types"
+)
+
+func defaultImporter() types.Importer {
+	return importer.For("source", nil)
+}

stringer.go

@@ -68,7 +68,6 @@ import (
 	"go/build"
 	exact "go/constant"
 	"go/format"
-	"go/importer"
 	"go/parser"
 	"go/token"
 	"go/types"
@@ -273,7 +272,7 @@ func (g *Generator) parsePackage(directory string, names []string, text interfac
 // check type-checks the package. The package must be OK to proceed.
 func (pkg *Package) check(fs *token.FileSet, astFiles []*ast.File) {
 	pkg.defs = make(map[*ast.Ident]types.Object)
-	config := types.Config{Importer: importer.For("source", nil), FakeImportC: true}
+	config := types.Config{Importer: defaultImporter(), FakeImportC: true}
 	info := &types.Info{
 		Defs: pkg.defs,
 	}