Merge KSP 1 and KSP 2 implementations into one module (#5768)

Consolidate all tasks into `KspModule` and introduce a config switch
`kspModuleMode` (not a task) to have different task dependency depending
on it's value.

All tasks specific to only one version have a `ksp1` or `ksp2` in their
name.

All unit and integration tests should keep running successfully.

I also envision to support KSP 2 In-Process mode, hence I implemented
the mode switch as enum.

Fix #5765

---------

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

Author: lefou

example/kotlinlib/basic/7-dependency-injection/build.mill

@@ -2,9 +2,9 @@
 
 package build
 import mill.*, kotlinlib.*
-import kotlinlib.ksp.Ksp2Module
+import kotlinlib.ksp.KspModule
 
-object dagger extends Ksp2Module {
+object dagger extends KspModule {
 
   def kotlinVersion = "2.2.0"
 
@@ -24,7 +24,7 @@ object dagger extends Ksp2Module {
     mvn"com.google.dagger:dagger-compiler:2.57"
   )
 
-  object test extends Ksp2Tests, TestModule.Junit5 {
+  object test extends KspTests, TestModule.Junit5 {
 
     def kotlincOptions = super.kotlincOptions() ++ Seq("-no-reflect", "-verbose")
 
@@ -46,14 +46,14 @@ object dagger extends Ksp2Module {
 
 /** Usage
 
-> ./mill show dagger.compile
+> ./mill dagger.compile
 
-> ls out/dagger/generatedSourcesWithKSP.dest/generated/java/com/example/dagger/
+> ls out/dagger/generatedSourcesWithKsp2Cli.dest/generated/java/com/example/dagger/
 DaggerNumberApp.java
 NumberService_Factory.java
 RandomNumberGenerator_Factory.java
 
-> ./mill show dagger.run
+> ./mill dagger.run
 Random number: ...
 
 > ./mill show dagger.test
@@ -77,7 +77,7 @@ Random number: ...
 }
 ...
 
-> ls out/dagger/test/generatedSourcesWithKSP.dest/generated/java/com/example/dagger/
+> ls out/dagger/test/generatedSourcesWithKsp2Cli.dest/generated/java/com/example/dagger/
 ConstantNumberGenerator_Factory.java
 DaggerDemoComponent.java
 DaggerTestApp.java

example/kotlinlib/web/8-hello-micronaut/build.mill

@@ -4,7 +4,7 @@ import coursier.{MavenRepository, Repository}
 
 import mill.*
 import kotlinlib.*
-import kotlinlib.ksp.Ksp2Module
+import kotlinlib.ksp.KspModule
 
 object micronaut extends MicronautModule {
 
@@ -29,7 +29,7 @@ object micronaut extends MicronautModule {
 
 }
 
-trait MicronautModule extends Ksp2Module { outer =>
+trait MicronautModule extends KspModule { outer =>
   def kspVersion: T[String] = "2.0.2"
   def kotlinVersion = "2.2.0"
   def kspJvmTarget: T[String] = "11"
@@ -50,17 +50,17 @@ trait MicronautModule extends Ksp2Module { outer =>
   }
 
   override def resources: T[Seq[PathRef]] = Task {
-    super.resources() ++ Seq(generatedSourcesWithKSP().resources)
+    super.resources() ++ Seq(generatedSourcesWithKsp().resources)
   }
 
   override def runClasspath: T[Seq[PathRef]] = Task {
-    super.runClasspath() ++ Seq(generatedSourcesWithKSP().classes)
+    super.runClasspath() ++ Seq(generatedSourcesWithKsp().classes)
   }
 
-  trait MicronautTests extends MicronautModule, Ksp2Tests {
+  trait MicronautTests extends MicronautModule, KspTests {
 
     override def resources: T[Seq[PathRef]] = Task {
-      super[Ksp2Tests].resources() ++ Seq(generatedSourcesWithKSP().resources)
+      super[KspTests].resources() ++ Seq(generatedSourcesWithKsp().resources)
     }
 
     def kotlinSymbolProcessors = Seq(
@@ -69,8 +69,8 @@ trait MicronautModule extends Ksp2Module { outer =>
 
     override def runClasspath: T[Seq[PathRef]] = Task {
       super.runClasspath() ++ Seq(
-        generatedSourcesWithKSP().classes,
-        outer.generatedSourcesWithKSP().classes
+        generatedSourcesWithKsp().classes,
+        outer.generatedSourcesWithKsp().classes
       )
     }
 

example/thirdparty/androidtodo/build.mill

@@ -1,7 +1,7 @@
 package build
 
 import mill.*, androidlib.*, kotlinlib.*
-import kotlinlib.ksp.Ksp2Module
+import kotlinlib.ksp.{KspModule, KspModuleMode}
 import hilt.AndroidHiltSupport
 
 object Versions {
@@ -19,12 +19,16 @@ object androidSdkModule0 extends AndroidSdkModule {
 }
 
 // Mill configuration for the Android Todo App project.
-object app extends AndroidAppKotlinModule, AndroidR8AppModule, AndroidBuildConfig,
-      Ksp2Module, AndroidHiltSupport {
+object app
+    extends AndroidAppKotlinModule,
+      AndroidR8AppModule,
+      AndroidBuildConfig,
+      AndroidHiltSupport {
 
   def kotlinVersion = Versions.kotlinVersion
   def kspVersion = Versions.kspVersion
   def kspJvmTarget = "17"
+  def kspModuleMode = KspModuleMode.Ksp2Cli
 
   override def androidDebugSettings: T[AndroidBuildTypeSettings] = Task {
     AndroidBuildTypeSettings(
@@ -109,7 +113,7 @@ object app extends AndroidAppKotlinModule, AndroidR8AppModule, AndroidBuildConfi
     mvn"com.google.dagger:hilt-android-compiler:2.56"
   )
 
-  object test extends Ksp2Tests, AndroidAppKotlinTests, AndroidHiltSupport, TestModule.Junit4 {
+  object test extends KspTests, AndroidAppKotlinTests, AndroidHiltSupport, TestModule.Junit4 {
 
     def moduleDeps = super.moduleDeps ++ Seq(`shared-test`)
 
@@ -145,8 +149,10 @@ object app extends AndroidAppKotlinModule, AndroidR8AppModule, AndroidBuildConfi
     )
   }
 
-  object androidTest extends AndroidAppKotlinInstrumentedTests, AndroidR8AppModule,
-        Ksp2Module, AndroidHiltSupport {
+  object androidTest
+      extends AndroidAppKotlinInstrumentedTests,
+        AndroidR8AppModule,
+        AndroidHiltSupport {
 
     def moduleDeps = super.moduleDeps ++ Seq(`shared-test`)
     def kspJvmTarget = "17"
@@ -211,7 +217,7 @@ object app extends AndroidAppKotlinModule, AndroidR8AppModule, AndroidBuildConfi
 
 }
 
-object `shared-test` extends AndroidKotlinModule, Ksp2Module, AndroidHiltSupport {
+object `shared-test` extends AndroidKotlinModule, AndroidHiltSupport {
 
   def moduleDeps = Seq(app)
 

libs/androidlib/src/mill/androidlib/hilt/AndroidHiltSupport.scala

@@ -2,7 +2,7 @@ package mill.androidlib.hilt
 
 import mill.androidlib.AndroidKotlinModule
 import mill.api.{ModuleRef, PathRef}
-import mill.kotlinlib.ksp.KspBaseModule
+import mill.kotlinlib.ksp.KspModule
 import mill.javalib.Dep
 import mill.javalib.api.CompilationResult
 import mill.{T, Task}
@@ -18,16 +18,11 @@ import mill.{T, Task}
  *
  * Usage:
  * ```
- *
- * object app extends KspModule, AndroidHiltSupport { ... }
- *
- * // or
- *
- * object app extends Ksp2Module, AndroidHiltSupport { ... }
+ * object app extends AndroidHiltSupport { ... }
  * ```
  */
 @mill.api.experimental
-trait AndroidHiltSupport extends KspBaseModule, AndroidKotlinModule {
+trait AndroidHiltSupport extends KspModule, AndroidKotlinModule {
 
   override def kspProcessorOptions: T[Map[String, String]] = Task {
     super.kspProcessorOptions() ++ Map(

libs/kotlinlib/src/mill/kotlinlib/ksp/GeneratedKspSources.scala

@@ -0,0 +1,14 @@
+package mill.kotlinlib.ksp
+
+import mill.api.PathRef
+import upickle.default.ReadWriter
+
+@mill.api.experimental
+case class GeneratedKspSources(
+    java: PathRef,
+    kotlin: PathRef,
+    resources: PathRef,
+    classes: PathRef
+) derives ReadWriter {
+  def sources: Seq[PathRef] = Seq(java, kotlin)
+}