debugging - How to debug with obfuscated (with ProGuard) applications on Android?

Question

When I got something like this

ERROR/AndroidRuntime(18677): Caused by: java.lang.NullPointerException
ERROR/AndroidRuntime(18677):     at com.companyname.a.a.a(Unknown Source)

How can I know where the problem is and debug this issue? I only got the mapping output from ProGuard and don't know the line number. Thanks.

Answer 1

Add the following lines to your proguard configuration.

-renamesourcefileattribute SourceFile    
-keepattributes SourceFile,LineNumberTable

Now your stack traces will include line numbers, and by using the retrace tool that ships with proguard (included in the Android SDK), you are able to debug like normal.

Note that even if you didn't use these two configuration options, retrace still can output useful information provided you have the mappings file, albeit not totally unambiguously.

Note: the file with the mappings is produced by the proguard configuration option:

 -printmapping outputfile.txt

In the ant file shipped with the Android SDK, it is set to mapping.txt.

Good luck.