Android ProGuard - Obfuscating and Shrinking your code Remove trace logging (and other) statements at build time


Example

If you want to remove calls to certain methods, assuming they return void and have no side affects (as in, calling them doesn't change any system values, reference arguments, statics, etc.) then you can have ProGuard remove them from the output after the build is complete.

For example, I find this useful in removing debug/verbose logging statements useful in debugging, but generating the strings for them is unnecessary in production.

# Remove the debug and verbose level Logging statements.
# That means the code to generate the arguments to these methods will also not be called.
# ONLY WORKS IF -dontoptimize IS _NOT_ USED in any ProGuard configs
-assumenosideeffects class android.util.Log {
    public static *** d(...);
    public static *** v(...);
}

Note: If -dontoptimize is used in any ProGuard config so that it is not minifying/removing unused code, then this will not strip out the statements. (But who would not want to remove unused code, right?)

Note2: this call will remove the call to log, but will not protect you code. The Strings will actually remain in the generated apk. Read more in this post.