Merge changes I91063ebb,Id859723b
* changes:
Differentiate between empty and nil input
Do not modify input in-place
diff --git a/android/apex.go b/android/apex.go
index 5dcf73b..823afbb 100644
--- a/android/apex.go
+++ b/android/apex.go
@@ -513,9 +513,8 @@
// exactly the same set of APEXes (and platform), i.e. if their apex_available
// properties have the same elements.
func AvailableToSameApexes(mod1, mod2 ApexModule) bool {
- // Use CopyOf to prevent non-determinism (b/275313114#comment1)
- mod1ApexAvail := SortedUniqueStrings(CopyOf(mod1.apexModuleBase().ApexProperties.Apex_available))
- mod2ApexAvail := SortedUniqueStrings(CopyOf(mod2.apexModuleBase().ApexProperties.Apex_available))
+ mod1ApexAvail := SortedUniqueStrings(mod1.apexModuleBase().ApexProperties.Apex_available)
+ mod2ApexAvail := SortedUniqueStrings(mod2.apexModuleBase().ApexProperties.Apex_available)
if len(mod1ApexAvail) != len(mod2ApexAvail) {
return false
}
diff --git a/android/util.go b/android/util.go
index 38e0a4d..08a3521 100644
--- a/android/util.go
+++ b/android/util.go
@@ -26,7 +26,11 @@
// CopyOf returns a new slice that has the same contents as s.
func CopyOf(s []string) []string {
- return append([]string(nil), s...)
+ // If the input is nil, return nil and not an empty list
+ if s == nil {
+ return s
+ }
+ return append([]string{}, s...)
}
// Concat returns a new slice concatenated from the two input slices. It does not change the input
@@ -276,6 +280,8 @@
// FirstUniqueStrings returns all unique elements of a slice of strings, keeping the first copy of
// each. It modifies the slice contents in place, and returns a subslice of the original slice.
func FirstUniqueStrings(list []string) []string {
+ // Do not moodify the input in-place, operate on a copy instead.
+ list = CopyOf(list)
// 128 was chosen based on BenchmarkFirstUniqueStrings results.
if len(list) > 128 {
return firstUniqueStringsMap(list)
@@ -332,6 +338,7 @@
// SortedUniqueStrings returns what the name says
func SortedUniqueStrings(list []string) []string {
+ // FirstUniqueStrings creates a copy of `list`, so the input remains untouched.
unique := FirstUniqueStrings(list)
sort.Strings(unique)
return unique
diff --git a/android/util_test.go b/android/util_test.go
index 5584b38..a2ef589 100644
--- a/android/util_test.go
+++ b/android/util_test.go
@@ -381,6 +381,14 @@
}
}
+func TestCopyOfEmptyAndNil(t *testing.T) {
+ emptyList := []string{}
+ copyOfEmptyList := CopyOf(emptyList)
+ AssertBoolEquals(t, "Copy of an empty list should be an empty list and not nil", true, copyOfEmptyList != nil)
+ copyOfNilList := CopyOf(nil)
+ AssertBoolEquals(t, "Copy of a nil list should be a nil list and not an empty list", true, copyOfNilList == nil)
+}
+
func ExampleCopyOf() {
a := []string{"1", "2", "3"}
b := CopyOf(a)