Question

Basically I am trying the same as this guy: How can I tell proguard to assume a package is not used? but am not able to add any comments.

I keep getting warnings like this:

Warning: org.jboss.netty.logging.Slf4JLogger: can't find referenced class org.slf4j.Logger

Basically, org.jboss.netty.logging.Slf4JLogger is referencing third party library class org.slf4j.Logger which is not part of my project. org.jboss.netty.logging.Slf4JLogger is not used either.

So I try to tell proguard not to load/use org.jboss.netty.logging.Slf4JLogger as proposed by Eric Lafortune but constantly fail in doing so.
I added -injars libs/netty-3.3.1.Final.jar(!**Slf4JLogger) or -injars libs/netty-3.3.1.Final.jar(!**Slf4JLogger.class) but this does not seem to do anything. Even
-injars libs/netty-3.3.1.Final.jar("!whatever is in here") yields the same results so I assume this option does not do anything…

How can I tell Proguard to not consider several specific classes in the netty.jar?

Answer 1

Using the latest ADT (18.0) which fixes some problems with ProGuard integration (as compared to ADT 16.00), I was able to successfully run my Netty based app with the following additional ProGuard Settings:

 # Get rid of warnings about unreachable but unused classes referred to by Netty
-dontwarn org.jboss.netty.**

# Needed by commons logging
-keep class org.apache.commons.logging.* {*;}

#Some Factory that seemed to be pruned
-keep class java.util.concurrent.atomic.AtomicReferenceFieldUpdater {*;}
-keep class java.util.concurrent.atomic.AtomicReferenceFieldUpdaterImpl{*;}

#Some important internal fields that where removed     
-keep class org.jboss.netty.channel.DefaultChannelPipeline{volatile <fields>;}

#A Factory which has a static factory implementation selector which is pruned
-keep class org.jboss.netty.util.internal.QueueFactory{static <fields>;}

#Some fields whose names need to be maintained because they are accessed using inflection
-keepclassmembernames class org.jboss.netty.util.internal.**{*;}

My conclusions about why a specific line is needed may not be 100% precise and this is definitly not the must tuned solutions but at least it works. Feel free to edit if you think you can improve this.