Work-around for crt objects with sdk: current

Test: convert libcups from Android.mk->Android.bp, mm -j64.

Change-Id: I4fddcfa5806d0ce27a229c37a078b0d93e9082a8

cc/binary.go

@@ -122,7 +122,7 @@ func (binary *binaryDecorator) linkerDeps(ctx DepsContext, deps Deps) Deps {
 				// version.
 				version := ctx.sdkVersion()
 				if version == "current" {
-					version = ctx.AConfig().PlatformSdkVersion()
+					version = getCurrentNdkPrebuiltVersion(ctx)
 				}
 
 				if binary.static() {

cc/cc.go

@@ -1193,4 +1193,11 @@ func lastUniqueElements(list []string) []string {
 	return list[totalSkip:]
 }
 
+func getCurrentNdkPrebuiltVersion(ctx DepsContext) string {
+	if ctx.AConfig().PlatformSdkVersionInt() > config.NdkMaxPrebuiltVersionInt {
+		return strconv.Itoa(config.NdkMaxPrebuiltVersionInt)
+	}
+	return ctx.AConfig().PlatformSdkVersion()
+}
+
 var Bool = proptools.Bool

cc/config/global.go

@@ -71,6 +71,8 @@ var (
 	GccCppStdVersion          = "gnu++11"
 	ExperimentalCStdVersion   = "gnu11"
 	ExperimentalCppStdVersion = "gnu++1z"
+
+	NdkMaxPrebuiltVersionInt = 24
 )
 
 var pctx = android.NewPackageContext("android/soong/cc/config")

cc/library.go

@@ -424,7 +424,7 @@ func (library *libraryDecorator) linkerDeps(ctx DepsContext, deps Deps) Deps {
 				// version.
 				version := ctx.sdkVersion()
 				if version == "current" {
-					version = ctx.AConfig().PlatformSdkVersion()
+					version = getCurrentNdkPrebuiltVersion(ctx)
 				}
 				deps.CrtBegin = "ndk_crtbegin_so." + version
 				deps.CrtEnd = "ndk_crtend_so." + version