Desugar Task should provide deps / --classpath_entry(s)

[erikpowa]

Steps to Reproduce

1. Build an app project with some binding library

Expected Behavior

desugar_deploy.jar desugaring .jar with dependencies without exception

Actual Behavior

Desugar entirely skips the --classpath_entry dependencies for .jar (or it's by design? please no) when desugar_deploy.jar gets called, causing failures just like:

1> Exception in thread "main" java.lang.TypeNotPresentException: Type okhttp3.Interceptor not present

Version Information

xa sdk 9.1.0.19

Fast repro + good scenario

xabug.zip

[JonDouglas]

desugar_deploy.jar is deprecated as it was a standalone desugar tool that was integrated into the d8/r8 pipeline, and thus our initial support for desugar does not handle this scenario. We will need to ensure we are accounting for this within our r8 and d8 proposal.

#2040

Our source for the desguar task can be found here:

https://github.com/xamarin/xamarin-android/blob/master/src/Xamarin.Android.Build.Tasks/Tasks/Desugar.cs

At first glance, it looks like we would need to add this --classpath_entry switch and append the respective .jar file name foreach item. @jonathanpeppers can chime in further on this.

[erikpowa]

I just patched the IL in here.

tested (with multidex) and it's working

commandLineBuilder.AppendSwitch("--classpath_entry ");
commandLineBuilder.AppendFileNameIfNotNull(text);

Won't PR it then if it's deprecated

[JonDouglas]

@erikpowa To be more specific, the desguar.jar is going to be deprecated in favor of the desugar step being included in the new dex compiler (d8). I don't believe the new dex compiler has an option to provide this argument. I'd defer to @jonathanpeppers whether he thinks it's worth to PR or not.

[jonathanpeppers]

@erikpowa feel free to send a PR!

I'm trying to follow what you're changing here, but not seeing exactly. There isn't a variable named text in our Desugar MSBuild task.

Are we missing jar files as --input? https://github.com/xamarin/xamarin-android/blob/f6c3288dd5a7f82c178ef30ad25c11d475f1daf4/src/Xamarin.Android.Build.Tasks/Tasks/Desugar.cs#L85-L92

Or do we need to specify --classpath_entry for each jar file in addition to --input?

[erikpowa]

@jonathanpeppers sorry, I modified the Xamarin.Android.Build.Tasks.dll with dnSpy, I was lazy to clone/edit/build/push from source, and yes, my repro shows the current standalone desugar fails if there are certain jars that needs it's dependencies as classpath_entry, othwerwise it fails if not passed as argument. (such as twitter-core)

The hackish way looks like this (just make every --input --classpath_entry aswell):

foreach (var jar in InputJars) { 
 	var output = Path.Combine (OutputDirectory, BitConverter.ToString (md5.ComputeHash (Encoding.UTF8.GetBytes (jar))) + Path.GetFileName (jar)); 
 	outputs.Add (output); 
 	cmd.AppendSwitch ("--classpath_entry"); 
 	cmd.AppendFileNameIfNotNull (jar); 
 	cmd.AppendSwitch ("--input "); 
 	cmd.AppendFileNameIfNotNull (jar); 
 	cmd.AppendSwitch ("--output "); 
 	cmd.AppendFileNameIfNotNull (output); 
 } 

[gmoney494]

@erikpowa another way to get past this error without modifiying the dll?

[erikpowa]

@gmoney494 don't think so, you can build it XA manually tho, but it's only working >=7.0, something is messing around under api 24

[erikpowa]

@gmoney494 or you can make a custom desugar task on jar files that runs before Desugar task and try addig one of these arguments aswell (but it's untested)