Merge "Make FirstTarget treat HostCross separately from Host" am: 0243999864

Original change: https://android-review.googlesource.com/c/platform/build/soong/+/2160016

Change-Id: I879353c72a52b0ed98c39dfbf9ae5b278209198e
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

android/arch.go

@@ -1843,20 +1843,23 @@ func getCommonTargets(targets []Target) []Target {
 }
 
 // FirstTarget takes a list of Targets and a list of multilib values and returns a list of Targets
-// that contains zero or one Target for each OsType, selecting the one that matches the earliest
-// filter.
+// that contains zero or one Target for each OsType and HostCross, selecting the one that matches
+// the earliest filter.
 func FirstTarget(targets []Target, filters ...string) []Target {
 	// find the first target from each OS
 	var ret []Target
-	hasHost := false
-	set := make(map[OsType]bool)
+	type osHostCross struct {
+		os        OsType
+		hostCross bool
+	}
+	set := make(map[osHostCross]bool)
 
 	for _, filter := range filters {
 		buildTargets := filterMultilibTargets(targets, filter)
 		for _, t := range buildTargets {
-			if _, found := set[t.Os]; !found {
-				hasHost = hasHost || (t.Os.Class == Host)
-				set[t.Os] = true
+			key := osHostCross{t.Os, t.HostCross}
+			if _, found := set[key]; !found {
+				set[key] = true
 				ret = append(ret, t)
 			}
 		}