libbinder: stricter APEX + VNDK stability checks

This is in preparation for splitting system/apex stability and also
ensures there are no surprises if/when vendor APEXes are introduced by
specifically checking that the only __ANDROID_APEX__ + __ANDROID_VNDK__
case is com.android.media, which is compiled with vendor code, but
shipped with the system partition.

Bug: 139325195
Test: build checks satifised, TEST_MAPPING
Change-Id: Id72e40addb4ab4b7a7e2e35a90c1ca0d0a51558a

1 files changed, 21 insertions, 2 deletions

diff --git a/libs/binder/Stability.cpp b/libs/binder/Stability.cpp
index e1565fac43..6115aec81d 100644
--- a/libs/binder/Stability.cpp
+++ b/libs/binder/Stability.cpp
@@ -22,7 +22,7 @@ namespace android {
 namespace internal {
 
 void Stability::markCompilationUnit(IBinder* binder) {
-    status_t result = set(binder, kLocalStability, true /*log*/);
+    status_t result = set(binder, getLocalStability(), true /*log*/);
     LOG_ALWAYS_FATAL_IF(result != OK, "Should only mark known object.");
 }
 
@@ -45,7 +45,26 @@ bool Stability::requiresVintfDeclaration(const sp<IBinder>& binder) {
 }
 
 void Stability::tryMarkCompilationUnit(IBinder* binder) {
-    (void) set(binder, kLocalStability, false /*log*/);
+    (void) set(binder, getLocalStability(), false /*log*/);
+}
+
+Stability::Level Stability::getLocalStability() {
+#ifdef __ANDROID_VNDK__
+    #ifdef __ANDROID_APEX__
+        // TODO(b/142684679) avoid use_vendor on system APEXes
+        #if !defined(__ANDROID_APEX_COM_ANDROID_MEDIA_SWCODEC__) \
+            && !defined(__ANDROID_APEX_TEST_COM_ANDROID_MEDIA_SWCODEC__)
+        #error VNDK + APEX only defined for com.android.media.swcodec
+        #endif
+        // TODO(b/142684679) avoid use_vendor on system APEXes
+        return Level::SYSTEM;
+    #else
+        return Level::VENDOR;
+    #endif
+#else
+    // TODO(b/139325195): split up stability levels for system/APEX.
+    return Level::SYSTEM;
+#endif
 }
 
 status_t Stability::set(IBinder* binder, int32_t stability, bool log) {