--- /dev/null
+// Copyright 2018 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 analysisflags_test
+
+import (
+ "fmt"
+ "os"
+ "os/exec"
+ "runtime"
+ "strings"
+ "testing"
+
+ "golang.org/x/tools/go/analysis"
+ "golang.org/x/tools/go/analysis/internal/analysisflags"
+)
+
+func main() {
+ fmt.Println(analysisflags.Parse([]*analysis.Analyzer{
+ {Name: "a1", Doc: "a1"},
+ {Name: "a2", Doc: "a2"},
+ {Name: "a3", Doc: "a3"},
+ }, true))
+ os.Exit(0)
+}
+
+// This test fork/execs the main function above.
+func TestExec(t *testing.T) {
+ if runtime.GOOS != "linux" {
+ t.Skipf("skipping fork/exec test on this platform")
+ }
+
+ progname := os.Args[0]
+
+ if os.Getenv("ANALYSISFLAGS_CHILD") == "1" {
+ // child process
+ os.Args = strings.Fields(progname + " " + os.Getenv("FLAGS"))
+ main()
+ panic("unreachable")
+ }
+
+ for _, test := range []struct {
+ flags string
+ want string
+ }{
+ {"", "[a1 a2 a3]"},
+ {"-a1=0", "[a2 a3]"},
+ {"-a1=1", "[a1]"},
+ {"-a1", "[a1]"},
+ {"-a1=1 -a3=1", "[a1 a3]"},
+ {"-a1=1 -a3=0", "[a1]"},
+ } {
+ cmd := exec.Command(progname, "-test.run=TestExec")
+ cmd.Env = append(os.Environ(), "ANALYSISFLAGS_CHILD=1", "FLAGS="+test.flags)
+
+ output, err := cmd.CombinedOutput()
+ if err != nil {
+ t.Fatalf("exec failed: %v; output=<<%s>>", err, output)
+ }
+
+ got := strings.TrimSpace(string(output))
+ if got != test.want {
+ t.Errorf("got %s, want %s", got, test.want)
+ }
+ }
+}