Proguard: How to avoid shrinking (and obfuscating) an entire package to avoid removing (and obfuscating) "unused methods"?

Question

I'm currently using an Android library that uses a lot of reflection.

As soon as I enable proguard, and run it... it crashes.

Why? It uses a lot of reflection and the methods are only invoked via reflection, so they are detected by proguard as unused and removed during the shrinking process, so a a NoSuchMethodError is thrown.

Why this happens? That is easy to figure out they are removed during the shrinking process as proguard considers they are unused and therefore removes that pieces of code (all the methods)

So, how can I configure proguard to avoid shrinking or obfuscating an entire package? (the library)

Note: I don't want to use the -dontshrink option, as it's all or nothing and I just want to avoid a specific package.

More info:

The runtime error is the following:

E/AndroidRuntime: FATAL EXCEPTION: main Process: com.my.app.debug, PID: 3771 
java.lang.NoSuchMethodError: observeValueForKeyPath [class java.lang.String, class java.lang.Object, class com.my.lib.util.Dictionary, class java.lang.Object]
at com.my.lib.util.Observable$ObservationManager$Observer.<init>(SourceFile:47)
at com.my.lib.util.Observable$ObservationManager$Observer.<init>(SourceFile:26)
at com.my.lib.util.Observable$ObservationManager.addObserver(SourceFile:159)
...

Take note that the problem is one an inner inner class...

My current configuration has something like:

-keep,includedescriptorclasses class com.my.** { *; }
-keepclassmembers class com.my.lib** { *; }
-keep,includedescriptorclasses class com.my.lib.util.Observable$* { *; }
-keep,includedescriptorclasses class com.my.lib.util.Observable$*$* { *; }

But this apparently only avoids obfuscating the methods not removed during the shrinking process... I need to avoid removing methods during shrinking.

Possible duplicate of [How to keep/exclude a particular package path when using proguard?](http://stackoverflow.com/questions/4830474/how-to-keep-exclude-a-particular-package-path-when-using-proguard) — Elltz, Apr 01 '16 at 18:52
It's not a duplicate. I'm specifically searching for a way to disable shrinking that the other answer doesn't solve (and obfuscation which the other answer indeed answers). — neteinstein, Apr 01 '16 at 21:21
Why is the global -dontshrink so terrible. Do you **need** your app shrunk. Is the shrinking worth the pain it's currently causing you? — Richard Tingle, Apr 03 '16 at 21:29
Why should I stop shrinking my app just because a lib uses reflection? I can, but that's just the easy way. — neteinstein, Apr 03 '16 at 21:33

score 3 · Accepted Answer · answered Apr 04 '16 at 17:10

3

According to the documentation -keep should work even when shrinking, while -keepclassmembers only works "if [the] classes are preserved as well".

answered Apr 04 '16 at 17:10

F43nd1r

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Actually you are right. I was doing something else wrong. – neteinstein Apr 04 '16 at 22:50

score 0 · Answer 2 · answered Apr 01 '16 at 18:32

0

-keep class com.library.** { *; }

answered Apr 01 '16 at 18:32

gaara87

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This doesn't work because the shrinking removes the methods not used.. so it only keeps unobfuscated those which are detected as used. Reflection isn't detected using in compile time.. – neteinstein Apr 01 '16 at 21:09
true, your question did not mention the specificity of the reflection usage. But yea you are right, – gaara87 Apr 01 '16 at 21:13
Added more info to help with the answers. – neteinstein Apr 04 '16 at 22:18
So how is my answer wrong if the answer selected as the correct one says the same thing I've done? – gaara87 Apr 04 '16 at 23:28
It's not. But the correct answer is not the same as yours. – neteinstein Apr 05 '16 at 09:42

score 0 · Answer 3 · answered Apr 05 '16 at 09:40

For the sake of people in the future with similar problems, I'll explain what really was happening:

The -keep class my.app.package was really avoiding methods to be removed by shrinking and obfuscated (@F43nd1r's answer made me realize that by really pointing that the docs said that it avoid also shrinking), so the problem was elsewhere
After decompiling the lib's code and passing some time reading it, I found that it received as a parameter an instance of another class (not from that lib) and a string with a method name that it used for reflection. That was the problem, I needed to also avoid obfuscating that class.

score 0 · Answer 4 · answered Jul 13 '18 at 10:55

0

I use the option -dontshrink to prevent shrinking. Source: link

answered Jul 13 '18 at 10:55

YetAnotherBot

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Proguard: How to avoid shrinking (and obfuscating) an entire package to avoid removing (and obfuscating) "unused methods"?

4 Answers4