GenerateJavaStubs takes a long time when building incrementally for a maui project

[dellis1972]

Android application type

.NET Android (net7.0-android, net8.0-android, etc.)

Affected platform version

.NET 8.x

Description

I am seeing a 7 second task run time when building a Maui applicaiton incrementally.

 7214 ms  GenerateJavaStubs                          1 calls

Steps to Reproduce

1. Create a new maui app (dotnet new maui)
2. dotnet build -f net8.0-android
3. change CounterBtn.Text = $"Clicked {count} time"; to CounterBtn.Text = $"Clicked {count} time(s)"; in MainPage.xml.cs
4. dortnet build -f net8.0-android -bl

Did you find any workaround?

None

Relevant log output

No response

[dellis1972]

android-inc.binlog.zip

[jpobst]

This seems to be related to the "per-RID assembly" and "marshal methods" changes.

We now do the following additional work we did not do previously:

• Scan Mono.Android.dll and Mono.Android.Export.dll for JLOs.
• Scan all assemblies for each architecture, which defaults to 4.

The actual "Generate Java Stubs" task does not need to scan Mono.Android.dll, and only needs one architecture to create the JLO's from.

The additional work is needed by LLVM marshal methods, but we should investigate if we can avoid it when that feature is disabled, like in Debug mode.

For context, on my DevBox, the MAUI template default clean build (no devices attached) timing for GenerateJavaStubs is:

• .NET 8 - 1.943s
• .NET 9 P3 - 10.970s