Add supports for using Source Generator using Directives

modules/build/src/main/scala/scala/build/Build.scala

@@ -861,6 +861,8 @@ object Build {
       if (options.useBuildServer.getOrElse(true)) None
       else releaseFlag(options, compilerJvmVersionOpt, logger).map(_.toString)
 
+    val hardcodedSource = options.sourceGeneratorOptions.generatorConfig
+
     val scalaCompilerParamsOpt = artifacts.scalaOpt match {
       case Some(scalaArtifacts) =>
         val params = value(options.scalaParams).getOrElse {
@@ -1009,7 +1011,8 @@ object Build {
       resourceDirs = sources.resourceDirs,
       scope = scope,
       javaHomeOpt = Option(options.javaHomeLocation().value),
-      javacOptions = javacOptions
+      javacOptions = javacOptions,
+      generateSource = Option(sourceGeneratorConfig)
     )
     project
   }

modules/build/src/main/scala/scala/build/Project.scala

@@ -7,10 +7,10 @@ import coursier.core.Classifier
 
 import java.io.ByteArrayOutputStream
 import java.nio.charset.StandardCharsets
-import java.nio.file.Path
+import java.nio.file.{Path, Paths}
 import java.util.Arrays
 
-import scala.build.options.{ScalacOpt, Scope, ShadowingSeq}
+import scala.build.options.{GeneratorConfig, ScalacOpt, Scope, ShadowingSeq}
 
 final case class Project(
   workspace: os.Path,
@@ -28,7 +28,8 @@ final case class Project(
   resourceDirs: Seq[os.Path],
   javaHomeOpt: Option[os.Path],
   scope: Scope,
-  javacOptions: List[String]
+  javacOptions: List[String],
+  generateSource: Option[Seq[GeneratorConfig]]
 ) {
 
   import Project._
@@ -50,6 +51,26 @@ final case class Project(
         bridgeJars = scalaCompiler0.bridgeJarsOpt.map(_.map(_.toNIO).toList)
       )
     }
+
+    val sourceGenerator: Option[List[BloopConfig.SourceGenerator]] =
+      generateSource.map(configs =>
+        configs.map { config =>
+          val command0 = config.commandFilePath
+          val sourceGlobs0 = BloopConfig.SourcesGlobs(
+            Paths.get(config.inputDir),
+            None,
+            config.glob,
+            Nil
+          )
+
+          BloopConfig.SourceGenerator(
+            List(sourceGlobs0),
+            (config.outputPath / "source-generator-output").toNIO,
+            command0
+          )
+        }.toList
+      )
+
     baseBloopProject(
       projectName,
       directory.toNIO,
@@ -65,7 +86,8 @@ final case class Project(
         platform = Some(platform),
         `scala` = scalaConfigOpt,
         java = Some(BloopConfig.Java(javacOptions)),
-        resolution = resolution
+        resolution = resolution,
+        sourceGenerators = sourceGenerator
       )
   }
 

modules/build/src/main/scala/scala/build/preprocessing/DirectivesPreprocessor.scala

@@ -78,6 +78,9 @@ case class DirectivesPreprocessor(
       )
     }
 
+    for (vals <- unusedDirectives) println(s"preprocess- ${vals.toString}  ${vals.key}") 
+
+
     val (optionsWithActualRequirements, optionsWithEmptyRequirements) =
       buildOptionsWithTargetRequirements.global.partition(_.requirements.nonEmpty)
     val summedOptionsWithNoRequirements =
@@ -137,6 +140,7 @@ case class DirectivesPreprocessor(
       .toMap
 
     val unused = directives.filter(d => !handlersMap.contains(d.key))
+    for (vals <- unused) println(s"${vals.toString}  ${vals.key}") 
 
     val res = directives
       .iterator

modules/build/src/main/scala/scala/build/preprocessing/directives/DirectivesPreprocessingUtils.scala

@@ -30,6 +30,7 @@ object DirectivesPreprocessingUtils {
       directives.ScalaJs.handler,
       directives.ScalaNative.handler,
       directives.ScalaVersion.handler,
+      directives.SourceGenerator.handler,
       directives.Sources.handler,
       directives.Tests.handler
     ).map(_.mapE(_.buildOptions))

modules/directives/src/main/scala/scala/build/directives/DirectiveValueParser.scala

@@ -138,6 +138,7 @@ object DirectiveValueParser {
   given DirectiveSingleValueParser[String] =
     (key, value, scopePath, path) =>
       value.asString.toRight {
+        println("do we get here?")
         val pos = value.position(path)
         new MalformedDirectiveError(
           message =

modules/directives/src/main/scala/scala/build/preprocessing/directives/SourceGenerator.scala

@@ -0,0 +1,38 @@
+package scala.build.preprocessing.directives
+
+import scala.cli.commands.SpecificationLevel
+import scala.build.directives.*
+import scala.build.EitherCps.{either, value}
+import scala.build.Ops.*
+import scala.build.errors.{BuildException, CompositeBuildException}
+import scala.build.options.{BuildOptions, SourceGeneratorOptions, GeneratorConfig}
+import scala.build.options.GeneratorConfig
+import scala.build.{Positioned, options}
+
+@DirectiveUsage("//> using sourceGenerator", "`//> using sourceGenerator`")
+@DirectiveDescription("Generate code using Source Generator")
+@DirectiveLevel(SpecificationLevel.EXPERIMENTAL)
+final case class SourceGenerator(
+  sourceGenerator: DirectiveValueParser.WithScopePath[List[Positioned[String]]] =
+    DirectiveValueParser.WithScopePath.empty(Nil)
+) extends HasBuildOptions {
+  def buildOptions: Either[BuildException, BuildOptions] =
+    SourceGenerator.buildOptions(sourceGenerator)
+}
+
+object SourceGenerator {
+  val handler: DirectiveHandler[SourceGenerator] = DirectiveHandler.derive
+  def buildOptions(sourceGenerator: DirectiveValueParser.WithScopePath[List[Positioned[String]]])
+    : Either[BuildException, BuildOptions] = {
+    val sourceGenValue = sourceGenerator.value
+    sourceGenValue
+      .map(config => GeneratorConfig.parse(config, sourceGenerator.scopePath.subPath))
+      .sequence
+      .left.map(CompositeBuildException(_))
+      .map { configs =>
+        BuildOptions(sourceGeneratorOptions =
+          SourceGeneratorOptions(generatorConfig = configs)
+        )
+      }
+  }
+}

modules/options/src/main/scala/scala/build/options/BuildOptions.scala

@@ -45,7 +45,7 @@ final case class BuildOptions(
   testOptions: TestOptions = TestOptions(),
   notForBloopOptions: PostBuildOptions = PostBuildOptions(),
   sourceGeneratorOptions: SourceGeneratorOptions = SourceGeneratorOptions(),
-  useBuildServer: Option[Boolean] = None
+  useBuildServer: Option[Boolean] = None,
 ) {
 
   import BuildOptions.JavaHomeInfo

modules/options/src/main/scala/scala/build/options/GeneratorConfig.scala

@@ -0,0 +1,30 @@
+package scala.build.options
+
+import scala.build.Positioned
+import scala.build.errors.{BuildException, MalformedInputError}
+
+final case class GeneratorConfig(
+  inputDir: String,
+  glob: List[String],
+  commandFilePath: List[String],
+  outputPath: os.SubPath
+)
+
+object GeneratorConfig {
+
+  def parse(input: Positioned[String], output: os.SubPath): Either[BuildException, GeneratorConfig] =
+    input.value.split("\\|", 3) match {
+      case Array(inputDir, glob, commandFilePath) =>
+        val commandFileList = commandFilePath.split(" ").toList
+        Right(GeneratorConfig(inputDir, List(glob), commandFileList, output))
+      case _ =>
+        Left(
+          new MalformedInputError(
+            "sourceGenerator",
+            input.value,
+            "inputDir|glob|commandFilePath",
+            input.positions
+          )
+        )
+    }
+}

modules/options/src/main/scala/scala/build/options/SourceGeneratorOptions.scala

@@ -3,7 +3,8 @@ package scala.build.options
 final case class SourceGeneratorOptions(
   useBuildInfo: Option[Boolean] = None,
   projectVersion: Option[String] = None,
-  computeVersion: Option[ComputeVersion] = None
+  computeVersion: Option[ComputeVersion] = None,
+  generatorConfig: Seq[GeneratorConfig] = Nil,
 )
 
 object SourceGeneratorOptions {