Make Kotlin DSL model builder compatible with Isolated Projects

[bamboo]

• [x] Is this model builder used during the initial sync? yes
• [ ] review KotlinBuildScriptModelBuilder.scriptModelBuilderFor
• [ ] review KotlinDslScriptsModelBuilderKt.collectKotlinDslScripts
• [ ] review KotlinBuildScriptModelBuilderKt.sourceSets

[alllex]

Models for Sync

The only Kotlin DSL related model requested by recent versions of IntelliJ during sync is KotlinDslScriptsModel (plural).

It is invoked without providing explicit parameters (via system properties). In this case the model builder itself tries to traverse the build and discover all relevant Kotlin scripts with collectKotlinDslScripts function.

Known violations

There are a number of Isolated Projects violations that appear if we run all Kotlin DSL TAPI cross version tests.

• Project.classLoaderScope call (sources)
  • This is not a problem by itself, and it should be solved by making class path computation be part of the isolated builder
• Trying to make tasks in current project dependsOn a task from the root (sources)
  • not a sync violation
• Finding an enclosing source set for a script (entry point)
  • In sync scenario we will avoid that by discovering scripts together with source sets at the initial phase
• Project.buildscript for collecting the source path of a script (source)
  • Solvable via model aggregation
• project.serviceOf<ClassPathModeExceptionCollector>() (source)
• Project.layout.buildDirectory to make a certain directory a scriptClassPath (source)
  • This should be solved by building an isolated model

[alllex]

This was partially fixed in https://github.com/gradle/gradle/pull/27434, however, the support is not fully complete feature-wise.

[alllex]

Some of the existing use cases for fetching Kotlin DSL models are not yet covered by the existing model builders under Isolated Projects. Those will still need to be addressed during the IP Adoption phase or earlier