Android Studio - Proguard 'keep' rules being ignored?

Question

I have recently migrated my Android project from Eclipse to Android Studio.

The debug version of the app created by Android Studio runs fine on a device, but the release version crashes on startup.

Here is my app's build.gradle file:

apply plugin: 'com.android.application'
apply plugin: 'com.google.gms.google-services'

android {
    compileSdkVersion 23
    buildToolsVersion "23.0.2"

    defaultConfig {
        applicationId "com.example.myapp"
        minSdkVersion 15
        targetSdkVersion 23
        versionCode 49
        versionName "1.3.1"
    }
    buildTypes {
        release {
            minifyEnabled true
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
    packagingOptions {
        //exclude 'META-INF/DEPENDENCIES'
        exclude 'META-INF/NOTICE'
        exclude 'META-INF/LICENSE'
        exclude 'META-INF/LICENSE.txt'
        exclude 'META-INF/NOTICE.txt'
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    testCompile 'junit:junit:4.12'
    compile 'com.android.support:appcompat-v7:23.1.1'
    compile 'com.android.support:design:23.1.1'
    compile 'com.android.support:support-v13:23.1.1'
    compile 'org.apache.httpcomponents:httpmime:4.2.3'
    compile 'org.twitter4j:twitter4j-core:4.0.2'
    compile 'com.facebook.android:facebook-android-sdk:4.8.2'
    compile 'ch.acra:acra:4.7.0'
    compile 'com.google.android.gms:play-services-analytics:8.3.0'
    compile 'com.google.android.gms:play-services-ads:8.3.0'
    compile 'com.google.android.gms:play-services-plus:8.3.0'
    //compile 'com.google.android.gms:play-services:8.3.0'
    compile 'com.google.android.gms:play-services-gcm:8.3.0'
}

Here is my proguard-rules.pro file:

# Add project specific ProGuard rules here.
# By default, the flags in this file are appended to flags specified
# in P:\Program Files\Android\sdk/tools/proguard/proguard-android.txt
# You can edit the include path and order by changing the proguardFiles
# directive in build.gradle.
#
# For more details, see
#   http://developer.android.com/guide/developing/tools/proguard.html

# Add any project specific keep options here:

# If your project uses WebView with JS, uncomment the following
# and specify the fully qualified class name to the JavaScript interface
# class:
#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
#   public *;
#}



#
# My Classes - start
#

-keep public class com.example.myapp.SplashActivity
-keep public class com.example.myapp.FragmentActivityWithListener
-keep public class com.example.myapp.AbstractHelpActivity
-keep public class com.example.myapp.GetContentFromWebTask$CompletedListener
# Don't rename the MenuBuilder filename as this is referenced in our AbstractHelpActivity.java file
-keep public class android.support.v7.internal.view.menu.MenuBuilder
-keep class android.support.v7.widget.ShareActionProvider { *; }

#
# My Classes - end
#


#
# Twitter library - start
#

-dontwarn twitter4j.**
-keep class twitter4j.** { *; }

#
# Twitter library - end
#


#
# Google Play Service library - start
#

-keep class * extends java.util.ListResourceBundle {
    protected Object[][] getContents();
}

-keep public class com.google.android.gms.common.internal.safeparcel.SafeParcelable {
    public static final *** NULL;
}

-keepnames @com.google.android.gms.common.annotation.KeepName class *
-keepclassmembernames class * {
    @com.google.android.gms.common.annotation.KeepName *;
}

-keepnames class * implements android.os.Parcelable {
    public static final ** CREATOR;
}

#
# Google Play Service library - end
#


#
# ACRA - start
#

#ACRA specifics
# Restore some Source file names and restore approximate line numbers in the stack traces,
# otherwise the stack traces are pretty useless
-keepattributes SourceFile,LineNumberTable

# ACRA needs "annotations" so add this...
# Note: This may already be defined in the default "proguard-android-optimize.txt"
# file in the SDK. If it is, then you don't need to duplicate it. See your
# "project.properties" file to get the path to the default "proguard-android-optimize.txt".
-keepattributes *Annotation*

# keep this class so that logging will show 'ACRA' and not a obfuscated name like 'a'.
# Note: if you are removing log messages elsewhere in this file then this isn't necessary
-keep class org.acra.ACRA {
    *;
}

# keep this around for some enums that ACRA needs
-keep class org.acra.ReportingInteractionMode {
    *;
}

-keepnames class org.acra.sender.HttpSender$** {
    *;
}

-keepnames class org.acra.ReportField {
    *;
}

# keep this otherwise it is removed by ProGuard
-keep public class org.acra.ErrorReporter {
    public void addCustomData(java.lang.String,java.lang.String);
    public void putCustomData(java.lang.String,java.lang.String);
    public void removeCustomData(java.lang.String);
}

# keep this otherwise it is removed by ProGuard
-keep public class org.acra.ErrorReporter {
    public void handleSilentException(java.lang.Throwable);
}

#
# ACRA - end
#


#
# Facebook - start
#
-keep class com.facebook.** { *; }
-keepattributes Signature
#
# Facebook - end
#

Here is the stack trace:

01-06 11:48:58.313 27667-27667/? E/ACRA: ACRA caught a RuntimeException for com.example.myapp
     java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.myapp/com.example.myapp.SplashActivity}: java.lang.ClassNotFoundException: Didn't find class "com.example.myapp.SplashActivity" on path: DexPathList[[zip file "/data/app/com.example.myapp-1/base.apk"],nativeLibraryDirectories=[/vendor/lib, /system/lib]]
         at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2650)
         at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2873)
         at android.app.ActivityThread.access$900(ActivityThread.java:181)
         at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1482)
         at android.os.Handler.dispatchMessage(Handler.java:102)
         at android.os.Looper.loop(Looper.java:145)
         at android.app.ActivityThread.main(ActivityThread.java:6145)
         at java.lang.reflect.Method.invoke(Native Method)
         at java.lang.reflect.Method.invoke(Method.java:372)
         at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1399)
         at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1194)
      Caused by: java.lang.ClassNotFoundException: Didn't find class "com.example.myapp.SplashActivity" on path: DexPathList[[zip file "/data/app/com.example.myapp-1/base.apk"],nativeLibraryDirectories=[/vendor/lib, /system/lib]]
         at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
         at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
         at java.lang.ClassLoader.loadClass(ClassLoader.java:469)
         at android.app.Instrumentation.newActivity(Instrumentation.java:1079)
         at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2640)
         at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2873) 
         at android.app.ActivityThread.access$900(ActivityThread.java:181) 
         at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1482) 
         at android.os.Handler.dispatchMessage(Handler.java:102) 
         at android.os.Looper.loop(Looper.java:145) 
         at android.app.ActivityThread.main(ActivityThread.java:6145) 
         at java.lang.reflect.Method.invoke(Native Method) 
         at java.lang.reflect.Method.invoke(Method.java:372) 
         at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1399) 
         at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1194) 
        Suppressed: java.lang.NoClassDefFoundError: com.example.myapp.SplashActivity
         at dalvik.system.DexFile.defineClassNative(Native Method)
         at dalvik.system.DexFile.defineClass(DexFile.java:226)
         at dalvik.system.DexFile.loadClassBinaryName(DexFile.java:219)
         at dalvik.system.DexPathList.findClass(DexPathList.java:321)
         at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:54)
                ... 14 more
        Suppressed: java.lang.ClassNotFoundException: com.example.myapp.SplashActivity
         at java.lang.Class.classForName(Native Method)
         at java.lang.BootClassLoader.findClass(ClassLoader.java:781)
         at java.lang.BootClassLoader.loadClass(ClassLoader.java:841)
         at java.lang.ClassLoader.loadClass(ClassLoader.java:504)
                ... 13 more
      Caused by: java.lang.NoClassDefFoundError: Class not found using the boot class loader; no stack available
01-06 11:48:58.363 27667-27667/? E/ACRA: Not adding buildConfig to log. Class Not found : com.example.myapp.BuildConfig. Please configure 'buildConfigClass' in your ACRA config
01-06 11:48:58.453 27667-27691/? E/ACRA: ACRA caught a InternalError for com.example.myapp
     java.lang.InternalError: Thread starting during runtime shutdown
         at java.lang.Thread.nativeCreate(Native Method)
         at java.lang.Thread.start(Thread.java:1063)
         at java.util.concurrent.ThreadPoolExecutor.addWorker(ThreadPoolExecutor.java:920)
         at java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:1336)
         at com.android.okhttp.ConnectionPool.get(ConnectionPool.java:211)
         at com.android.okhttp.internal.http.RouteSelector.next(RouteSelector.java:109)
         at com.android.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:368)
         at com.android.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:296)
         at com.android.okhttp.internal.http.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:399)
         at com.android.okhttp.internal.http.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:110)
         at org.acra.e.b.a(HttpRequest.java:122)
         at org.acra.sender.HttpSender.a(HttpSender.java:245)
         at org.acra.af.a(SendWorker.java:181)
         at org.acra.af.a(SendWorker.java:140)
         at org.acra.af.run(SendWorker.java:76)
01-06 11:48:58.483 27667-27691/? E/ACRA: Not adding buildConfig to log. Class Not found : com.example.myapp.BuildConfig. Please configure 'buildConfigClass' in your ACRA config
01-06 11:48:58.503 27667-27691/? E/AndroidRuntime: FATAL EXCEPTION: Thread-2863
               Process: com.example.myapp, PID: 27667
               java.lang.InternalError: Thread starting during runtime shutdown
                   at java.lang.Thread.nativeCreate(Native Method)
                   at java.lang.Thread.start(Thread.java:1063)
                   at java.util.concurrent.ThreadPoolExecutor.addWorker(ThreadPoolExecutor.java:920)
                   at java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:1336)
                   at com.android.okhttp.ConnectionPool.get(ConnectionPool.java:211)
                   at com.android.okhttp.internal.http.RouteSelector.next(RouteSelector.java:109)
                   at com.android.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:368)
                   at com.android.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:296)
                   at com.android.okhttp.internal.http.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:399)
                   at com.android.okhttp.internal.http.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:110)
                   at org.acra.e.b.a(HttpRequest.java:122)
                   at org.acra.sender.HttpSender.a(HttpSender.java:245)
                   at org.acra.af.a(SendWorker.java:181)
                   at org.acra.af.a(SendWorker.java:140)
                   at org.acra.af.run(SendWorker.java:76)
01-06 11:48:58.503 1038-1476/? W/ActivityManager:   Force finishing activity com.example.myapp/.SplashActivity

So it seems the keep rules I specified in my proguard-rules.pro file are not being used as the com.example.myapp.SplashActivity class cannot be found.

I have checked the Android Developers ProGuard page and it looks like I've set everything up correctly, so I've no idea why it isn't working.

Can anyone advice what I need to do in order to end up with an obfuscated apk that works?

Answer 1

I've found the problem. It was in my project's build.gradle file:

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    repositories {
        jcenter()       // This is the default repo
        mavenCentral()  // This is the Maven Central repo
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:1.3.0'
        classpath 'com.google.gms:google-services:1.5.0-beta2'

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        jcenter()       // This is the default repo
        mavenCentral()  // This is the Maven Central repo
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

The solution was to change the classpath 'com.android.tools.build:gradle:1.3.0' to classpath 'com.android.tools.build:gradle:1.5.0'.

(I discovered this by creating a new test project and comparing the values in the respective build.gradle files.)

Incidentally, the content of my proguard-rules.pro file is now just...

#
# Twitter - start
#

-dontwarn twitter4j.**
-keep class twitter4j.** { *; }

#
# Twitter - end
#


#
# Support library / ShareActionProvider - start
#

-keep class android.support.v7.internal.** { *; }
-keep interface android.support.v7.internal.** { *; }
-keep class android.support.v7.** { *; }
-keep interface android.support.v7.** { *; }

#
# Support library / ShareActionProvider - start
#


#
# ACRA - start
#

#ACRA specifics
# Restore some Source file names and restore approximate line numbers in the stack traces,
# otherwise the stack traces are pretty useless
-keepattributes SourceFile,LineNumberTable

# ACRA needs "annotations" so add this...
# Note: This may already be defined in the default "proguard-android-optimize.txt"
# file in the SDK. If it is, then you don't need to duplicate it. See your
# "project.properties" file to get the path to the default "proguard-android-optimize.txt".
-keepattributes *Annotation*

# keep this class so that logging will show 'ACRA' and not a obfuscated name like 'a'.
# Note: if you are removing log messages elsewhere in this file then this isn't necessary
-keep class org.acra.ACRA {
    *;
}

# keep this around for some enums that ACRA needs
-keep class org.acra.ReportingInteractionMode {
    *;
}

-keepnames class org.acra.sender.HttpSender$** {
    *;
}

-keepnames class org.acra.ReportField {
    *;
}

# keep this otherwise it is removed by ProGuard
-keep public class org.acra.ErrorReporter {
    public void addCustomData(java.lang.String,java.lang.String);
    public void putCustomData(java.lang.String,java.lang.String);
    public void removeCustomData(java.lang.String);
}

# keep this otherwise it is removed by ProGuard
-keep public class org.acra.ErrorReporter {
    public void handleSilentException(java.lang.Throwable);
}

#
# ACRA - end
#

...so I didn't need many of my old directives or the ones suggested by Dhawal in his answer.

NB - I understand the ACRA directives will not be required as of ACRA 4.8 .