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Commit 73bf054a authored by Paul Duffin's avatar Paul Duffin
Browse files

Abstract property value matching logic behind an interface 

Make it easy to add additional ways of matching property values. Needed
to add support for a 'starts with' matcher that can be used to restrict
allowable values in include_dir.

Test: m nothing
Bug: 35624006
Change-Id: I82e7d95f08847bf294aac311968e1d9f3e4b385d
parent 60c0cd9a

android/neverallow.go

+47 −10
Original line number Diff line number Diff line
@@ -156,9 +156,39 @@ func neverallowMutator(ctx BottomUpMutatorContext) { 
	}

}



type ValueMatcher interface {

	test(string) bool

	String() string

}



type equalMatcher struct {

	expected string

}



func (m *equalMatcher) test(value string) bool {

	return m.expected == value

}



func (m *equalMatcher) String() string {

	return "=" + m.expected

}



type anyMatcher struct {

}



func (m *anyMatcher) test(value string) bool {

	return true

}



func (m *anyMatcher) String() string {

	return "=*"

}



var anyMatcherInstance = &anyMatcher{}



type ruleProperty struct {

	fields  []string // e.x.: Vndk.Enabled

	value  string   // e.x.: true

	matcher ValueMatcher

}



// A NeverAllow rule.
@@ -220,7 +250,7 @@ func (r *rule) NotModuleType(types ...string) Rule { 
func (r *rule) With(properties, value string) Rule {

	r.props = append(r.props, ruleProperty{

		fields:  fieldNamesForProperties(properties),

		value:  value,

		matcher: selectMatcher(value),

	})

	return r

}
@@ -228,11 +258,18 @@ func (r *rule) With(properties, value string) Rule { 
func (r *rule) Without(properties, value string) Rule {

	r.unlessProps = append(r.unlessProps, ruleProperty{

		fields:  fieldNamesForProperties(properties),

		value:  value,

		matcher: selectMatcher(value),

	})

	return r

}



func selectMatcher(expected string) ValueMatcher {

	if expected == "*" {

		return anyMatcherInstance

	}

	return &equalMatcher{expected: expected}

}



func (r *rule) Because(reason string) Rule {

	r.reason = reason

	return r
@@ -253,10 +290,10 @@ func (r *rule) String() string { 
		s += " -type:" + v

	}

	for _, v := range r.props {

		s += " " + strings.Join(v.fields, ".") + "=" + v.value

		s += " " + strings.Join(v.fields, ".") + v.matcher.String()

	}

	for _, v := range r.unlessProps {

		s += " -" + strings.Join(v.fields, ".") + "=" + v.value

		s += " -" + strings.Join(v.fields, ".") + v.matcher.String()

	}

	if len(r.reason) != 0 {

		s += " which is restricted because " + r.reason
@@ -338,8 +375,8 @@ func hasProperty(properties []interface{}, prop ruleProperty) bool { 
			continue

		}



		check := func(v string) bool {

			return prop.value == "*" || prop.value == v

		check := func(value string) bool {

			return prop.matcher.test(value)

		}



		if matchValue(propertiesValue, check) {