From 927d6de11fa038ee78bb90933eee3ebc20b68751 Mon Sep 17 00:00:00 2001
From: David Brazdil <dbrazdil@google.com>
Date: Wed, 24 Jan 2018 19:54:30 +0000
Subject: [PATCH] Show a warning toast/dialog when an app uses hidden APIs

Check VMRuntime.hasUsedHiddenApi() on each Activity start and show
a toast/dialog urging the user to check logcat.

Test: manual
Bug: 64382372
Change-Id: Ida8a6ed9ab9b56a76882501b2a3473a5f1448cb3
---
 core/java/android/app/Activity.java | 29 +++++++++++++++++++++++++++--
 1 file changed, 27 insertions(+), 2 deletions(-)

diff --git a/core/java/android/app/Activity.java b/core/java/android/app/Activity.java
index dbdb81c7c666c..2e7a0ed86fdb2 100644
--- a/core/java/android/app/Activity.java
+++ b/core/java/android/app/Activity.java
@@ -128,6 +128,8 @@ import com.android.internal.app.WindowDecorActionBar;
 import com.android.internal.policy.DecorView;
 import com.android.internal.policy.PhoneWindow;
 
+import dalvik.system.VMRuntime;
+
 import java.io.FileDescriptor;
 import java.io.PrintWriter;
 import java.lang.annotation.Retention;
@@ -7039,11 +7041,12 @@ public class Activity extends ContextThemeWrapper
         mFragments.dispatchStart();
         mFragments.reportLoaderStart();
 
-        // This property is set for all builds except final release
-        boolean isDlwarningEnabled = SystemProperties.getInt("ro.bionic.ld.warning", 0) == 1;
         boolean isAppDebuggable =
                 (mApplication.getApplicationInfo().flags & ApplicationInfo.FLAG_DEBUGGABLE) != 0;
 
+        // This property is set for all builds except final release
+        boolean isDlwarningEnabled = SystemProperties.getInt("ro.bionic.ld.warning", 0) == 1;
+
         if (isAppDebuggable || isDlwarningEnabled) {
             String dlwarning = getDlWarning();
             if (dlwarning != null) {
@@ -7064,6 +7067,28 @@ public class Activity extends ContextThemeWrapper
             }
         }
 
+        // We might disable this for final builds.
+        boolean isApiWarningEnabled = true;
+
+        if (isAppDebuggable || isApiWarningEnabled) {
+            if (VMRuntime.getRuntime().hasUsedHiddenApi()) {
+                String appName = getApplicationInfo().loadLabel(getPackageManager())
+                        .toString();
+                String warning = "Detected problems with API compatiblity\n"
+                                 + "(please consult log for detail)";
+                if (isAppDebuggable) {
+                    new AlertDialog.Builder(this)
+                        .setTitle(appName)
+                        .setMessage(warning)
+                        .setPositiveButton(android.R.string.ok, null)
+                        .setCancelable(false)
+                        .show();
+                } else {
+                    Toast.makeText(this, appName + "\n" + warning, Toast.LENGTH_LONG).show();
+                }
+            }
+        }
+
         mActivityTransitionState.enterReady(this);
     }