IssueTracker

I found out that this feature will change the method signature and I don't want to have such optimization

There is no options to disable individual optimizations in R8. If there are parts of the program you would like to leave unchanged you should use keep rules covering these.

If you have a concrete issue related to signatures changes, please explain the details.

This optimization has an impact on our internal functions. We hope to have a switch to control this optimization.

Thank you. Can you be more specific about what you mean by an impact on our internal functions? Which failures do you get? Are you using reflection? If so, did you add keep rules for what you are reflecting on? The switch to disable optimizations are asking R8 to not optimize specific parts of the program with keep rules, see Customize which code to keep.

we record original method signature by asm, it will be used for next time to check and use. if method signatures changed, we can't find it and use

If you don't want any signatures to change and cannot limit this by using keep rules, then basically most R8 optimizations are out of the question. You could try to use -dontoptimize and -dontobfuscate to only have shrinking (removal of unused code). That is not the best way to use R8, but might cater for you use case.

That's a terrible suggestion.

Is it possible to add code to control this feature

I am sorry that you don't like the suggestion, but that is the way to ensure that signatures are not changed, if you are not able limit the surface by adding keep rules. Signature changes can arise from many different optimizations. We don't provide flags to disable individual optimizations, and if we did there was no single optimization to turn off to avoid signature changes.