Expand neverallow for sdk_version: none

Allow the platform stubs to specify sdk_version: none,
and add generic support for a regexp matcher.

Bug: 144149403
Test: m
Change-Id: Icaece0d9797bace8ae9741f7a029b9ea57fcbbb9

android/neverallow.go

@@ -17,6 +17,7 @@ package android
 import (
 	"path/filepath"
 	"reflect"
+	"regexp"
 	"strconv"
 	"strings"
 
@@ -147,7 +148,8 @@ func createLibcoreRules() []Rule {
 	rules := []Rule{
 		NeverAllow().
 			NotIn(coreLibraryProjects...).
-			With("sdk_version", "none"),
+			With("sdk_version", "none").
+			WithoutMatcher("name", Regexp("^android_.*stubs_current$")),
 	}
 
 	return rules
@@ -286,6 +288,18 @@ func (m *startsWithMatcher) String() string {
 	return ".starts-with(" + m.prefix + ")"
 }
 
+type regexMatcher struct {
+	re *regexp.Regexp
+}
+
+func (m *regexMatcher) test(value string) bool {
+	return m.re.MatchString(value)
+}
+
+func (m *regexMatcher) String() string {
+	return ".regexp(" + m.re.String() + ")"
+}
+
 type isSetMatcher struct{}
 
 func (m *isSetMatcher) test(value string) bool {
@@ -501,6 +515,14 @@ func StartsWith(prefix string) ValueMatcher {
 	return &startsWithMatcher{prefix}
 }
 
+func Regexp(re string) ValueMatcher {
+	r, err := regexp.Compile(re)
+	if err != nil {
+		panic(err)
+	}
+	return &regexMatcher{r}
+}
+
 // assorted utils
 
 func cleanPaths(paths []string) []string {

android/neverallow_test.go

@@ -226,6 +226,16 @@ var neverallowTests = []struct {
 				}`),
 		},
 	},
+	{
+		name: "sdk_version: \"none\" on android_*stubs_current stub",
+		fs: map[string][]byte{
+			"frameworks/base/Android.bp": []byte(`
+				java_library {
+					name: "android_stubs_current",
+					sdk_version: "none",
+				}`),
+		},
+	},
 	{
 		name: "sdk_version: \"none\" outside core libraries",
 		fs: map[string][]byte{