Add resources support to Scala Native and fixes to overall resources

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

@@ -16,6 +16,7 @@ import scala.build.Ops.*
 import scala.build.compiler.{ScalaCompiler, ScalaCompilerMaker}
 import scala.build.errors.*
 import scala.build.internal.{Constants, CustomCodeWrapper, MainClass, Util}
+import scala.build.internal.resource.ResourceMapper
 import scala.build.options.*
 import scala.build.options.validation.ValidationException
 import scala.build.postprocessing.*
@@ -392,9 +393,9 @@ object Build {
 
     val builds = value(buildScopes())
 
-    copyResourceToClassesDir(builds.main)
+    ResourceMapper.copyResourceToClassesDir(builds.main)
     for (testBuild <- builds.get(Scope.Test))
-      copyResourceToClassesDir(testBuild)
+      ResourceMapper.copyResourceToClassesDir(testBuild)
 
     if (actionableDiagnostics.getOrElse(false)) {
       val projectOptions = builds.get(Scope.Test).getOrElse(builds.main).options
@@ -404,26 +405,6 @@ object Build {
     builds
   }
 
-  private def copyResourceToClassesDir(build: Build): Unit = build match {
-    case b: Build.Successful =>
-      for {
-        resourceDirPath  <- b.sources.resourceDirs.filter(os.exists(_))
-        resourceFilePath <- os.walk(resourceDirPath).filter(os.isFile(_))
-        relativeResourcePath = resourceFilePath.relativeTo(resourceDirPath)
-        // dismiss files generated by scala-cli
-        if !relativeResourcePath.startsWith(os.rel / Constants.workspaceDirName)
-      } {
-        val destPath = b.output / relativeResourcePath
-        os.copy(
-          resourceFilePath,
-          destPath,
-          replaceExisting = true,
-          createFolders = true
-        )
-      }
-    case _ =>
-  }
-
   private def build(
     inputs: Inputs,
     sources: Sources,
@@ -482,36 +463,69 @@ object Build {
   def classesDir(root: os.Path, projectName: String, scope: Scope, suffix: String = ""): os.Path =
     classesRootDir(root, projectName) / s"${scope.name}$suffix"
 
+  def resourcesRegistry(
+    root: os.Path,
+    projectName: String,
+    scope: Scope
+  ): os.Path =
+    root / Constants.workspaceDirName / projectName / s"resources-${scope.name}"
+
   def scalaNativeSupported(
     options: BuildOptions,
-    inputs: Inputs
+    inputs: Inputs,
+    logger: Logger
   ): Either[BuildException, Option[ScalaNativeCompatibilityError]] =
     either {
       val scalaParamsOpt = value(options.scalaParams)
       scalaParamsOpt.flatMap { scalaParams =>
-        val scalaVersion  = scalaParams.scalaVersion
-        val nativeVersion = options.scalaNativeOptions.numeralVersion
-        val isCompatible = nativeVersion match {
-          case Some(snNumeralVer) =>
-            if (snNumeralVer < SNNumeralVersion(0, 4, 1) && Properties.isWin)
-              false
-            else if (scalaVersion.startsWith("3.0"))
-              false
-            else if (scalaVersion.startsWith("3") || scalaVersion.startsWith("2.12"))
-              snNumeralVer >= SNNumeralVersion(0, 4, 3)
-            else if (scalaVersion.startsWith("2.13"))
-              true
-            else false
-          case None => false
-        }
-        if (isCompatible) None
-        else
-          Some(
+        val scalaVersion       = scalaParams.scalaVersion
+        val nativeVersionMaybe = options.scalaNativeOptions.numeralVersion
+        def snCompatError =
+          Left(
             new ScalaNativeCompatibilityError(
               scalaVersion,
               options.scalaNativeOptions.finalVersion
             )
           )
+        def warnIncompatibleNativeOptions(numeralVersion: SNNumeralVersion) =
+          if (
+            numeralVersion < SNNumeralVersion(0, 4, 4)
+            && options.scalaNativeOptions.embedResources.isDefined
+          )
+            logger.diagnostic(
+              "This Scala Version cannot embed resources, regardless of the options used."
+            )
+
+        val numeralOrError: Either[ScalaNativeCompatibilityError, SNNumeralVersion] =
+          nativeVersionMaybe match {
+            case Some(snNumeralVer) =>
+              if (snNumeralVer < SNNumeralVersion(0, 4, 1) && Properties.isWin)
+                snCompatError
+              else if (scalaVersion.startsWith("3.0"))
+                snCompatError
+              else if (scalaVersion.startsWith("3"))
+                if (snNumeralVer >= SNNumeralVersion(0, 4, 3)) Right(snNumeralVer)
+                else snCompatError
+              else if (scalaVersion.startsWith("2.13"))
+                Right(snNumeralVer)
+              else if (scalaVersion.startsWith("2.12"))
+                if (
+                  inputs.sourceFiles().forall {
+                    case _: Inputs.AnyScript => snNumeralVer >= SNNumeralVersion(0, 4, 3)
+                    case _                   => true
+                  }
+                ) Right(snNumeralVer)
+                else snCompatError
+              else snCompatError
+            case None => snCompatError
+          }
+
+        numeralOrError match {
+          case Left(compatError) => Some(compatError)
+          case Right(snNumeralVersion) =>
+            warnIncompatibleNativeOptions(snNumeralVersion)
+            None
+        }
       }
     }
 
@@ -993,7 +1007,7 @@ object Build {
   ): Either[BuildException, Build] = either {
 
     if (options.platform.value == Platform.Native)
-      value(scalaNativeSupported(options, inputs)) match {
+      value(scalaNativeSupported(options, inputs, logger)) match {
         case None        =>
         case Some(error) => value(Left(error))
       }

modules/build/src/main/scala/scala/build/Inputs.scala

@@ -114,11 +114,6 @@ final case class Inputs(
           case dirInput: Inputs.Directory =>
             Seq("dir:") ++ Inputs.singleFilesFromDirectory(dirInput, enableMarkdown)
               .map(file => s"${file.path}:" + os.read(file.path))
-          case resDirInput: Inputs.ResourceDirectory =>
-            // Resource changes for SN require relinking, so they should also be hashed
-            Seq("resource-dir:") ++ os.walk(resDirInput.path)
-              .filter(os.isFile(_))
-              .map(filePath => s"$filePath:" + os.read(filePath))
           case _ => Seq(os.read(elem.path))
         }
         (Iterator(elem.path.toString) ++ content.iterator ++ Iterator("\n")).map(bytes)
@@ -206,6 +201,10 @@ object Inputs {
       extends OnDisk with SourceFile with Compiled {
     lazy val path: os.Path = base / subPath
   }
+  final case class CFile(base: os.Path, subPath: os.SubPath)
+      extends OnDisk with SourceFile with Compiled {
+    lazy val path = base / subPath
+  }
   final case class MarkdownFile(base: os.Path, subPath: os.SubPath)
       extends OnDisk with SourceFile {
     lazy val path: os.Path = base / subPath
@@ -245,6 +244,8 @@ object Inputs {
           Inputs.SourceScalaFile(d.path, p.subRelativeTo(d.path))
         case p if p.last.endsWith(".sc") =>
           Inputs.Script(d.path, p.subRelativeTo(d.path))
+        case p if p.last.endsWith(".c") || p.last.endsWith(".h") =>
+          Inputs.CFile(d.path, p.subRelativeTo(d.path))
         case p if p.last.endsWith(".md") && enableMarkdown =>
           Inputs.MarkdownFile(d.path, p.subRelativeTo(d.path))
       }
@@ -274,6 +275,7 @@ object Inputs {
           case _: Inputs.JavaFile          => "java:"
           case _: Inputs.SettingsScalaFile => "config:"
           case _: Inputs.SourceScalaFile   => "scala:"
+          case _: Inputs.CFile             => "c:"
           case _: Inputs.Script            => "sc:"
           case _: Inputs.MarkdownFile      => "md:"
         }
@@ -460,6 +462,7 @@ object Inputs {
       else if (arg.endsWith(".sc")) Right(Seq(Script(dir, subPath)))
       else if (arg.endsWith(".scala")) Right(Seq(SourceScalaFile(dir, subPath)))
       else if (arg.endsWith(".java")) Right(Seq(JavaFile(dir, subPath)))
+      else if (arg.endsWith(".c") || arg.endsWith(".h")) Right(Seq(CFile(dir, subPath)))
       else if (arg.endsWith(".md")) Right(Seq(MarkdownFile(dir, subPath)))
       else if (os.isDir(path)) Right(Seq(Directory(path)))
       else if (acceptFds && arg.startsWith("/dev/fd/")) {

modules/build/src/main/scala/scala/build/internal/resource/NativeResourceMapper.scala

@@ -0,0 +1,36 @@
+package scala.build.internal.resource
+
+import scala.build.{Build, Inputs}
+
+object NativeResourceMapper {
+
+  private def scalaNativeCFileMapping(build: Build.Successful): Map[os.Path, os.RelPath] =
+    build
+      .inputs
+      .flattened()
+      .collect {
+        case cfile: Inputs.CFile =>
+          val inputPath = cfile.path
+          val destPath  = os.rel / "scala-native" / cfile.subPath
+          (inputPath, destPath)
+      }
+      .toMap
+
+  private def resolveProjectCFileRegistryPath(nativeWorkDir: os.Path) =
+    nativeWorkDir / ".native_registry"
+
+  /** Copies and maps c file resources from their original path to the destination path in build
+    * output, also caching output paths in a file.
+    *
+    * Remembering the mapping this way allows for the resource to be removed if the original file is
+    * renamed/deleted.
+    */
+  def copyCFilesToScalaNativeDir(build: Build.Successful, nativeWorkDir: os.Path): Unit = {
+    val mappingFilePath = resolveProjectCFileRegistryPath(nativeWorkDir)
+    ResourceMapper.copyResourcesToDirWithMapping(
+      build.output,
+      mappingFilePath,
+      scalaNativeCFileMapping(build)
+    )
+  }
+}

modules/build/src/main/scala/scala/build/internal/resource/ResourceMapper.scala

@@ -0,0 +1,69 @@
+package scala.build.internal.resource
+
+import scala.build.Build
+import scala.build.internal.Constants
+
+object ResourceMapper {
+
+  private def resourceMapping(build: Build.Successful): Map[os.Path, os.RelPath] = {
+    val seq = for {
+      resourceDirPath  <- build.sources.resourceDirs.filter(os.exists(_))
+      resourceFilePath <- os.walk(resourceDirPath).filter(os.isFile(_))
+      relativeResourcePath = resourceFilePath.relativeTo(resourceDirPath)
+      // dismiss files generated by scala-cli
+      if !relativeResourcePath.startsWith(os.rel / Constants.workspaceDirName)
+    } yield (resourceFilePath, relativeResourcePath)
+
+    seq.toMap
+  }
+
+  def copyResourcesToDirWithMapping(
+    output: os.Path,
+    registryFilePath: os.Path,
+    newMapping: Map[os.Path, os.RelPath]
+  ): Unit = {
+
+    val oldRegistry =
+      if (os.exists(registryFilePath))
+        os.read(registryFilePath)
+          .linesIterator
+          .filter(_.nonEmpty)
+          .map(os.RelPath(_))
+          .toSet
+      else
+        Set.empty
+    val removedFiles = oldRegistry -- newMapping.values
+
+    for (f <- removedFiles)
+      os.remove(output / f)
+
+    for ((inputPath, outputPath) <- newMapping)
+      os.copy(
+        inputPath,
+        output / outputPath,
+        replaceExisting = true,
+        createFolders = true
+      )
+
+    if (newMapping.isEmpty)
+      os.remove(registryFilePath)
+    else
+      os.write.over(
+        registryFilePath,
+        newMapping.map(_._2.toString).toVector.sorted.mkString("\n")
+      )
+  }
+
+  /** Copies and maps resources from their original path to the destination path in build output,
+    * also caching output paths in a file.
+    *
+    * Remembering the mapping this way allows for the resource to be removed if the original file is
+    * renamed/deleted.
+    */
+  def copyResourceToClassesDir(build: Build): Unit = build match {
+    case b: Build.Successful =>
+      val fullFilePath = Build.resourcesRegistry(b.inputs.workspace, b.inputs.projectName, b.scope)
+      copyResourcesToDirWithMapping(b.output, fullFilePath, resourceMapping(b))
+    case _ =>
+  }
+}

modules/cli-options/src/main/scala/scala/cli/commands/ScalaNativeOptions.scala

@@ -43,7 +43,12 @@ final case class ScalaNativeOptions(
   @Group("Scala Native")
   @Hidden
   @HelpMessage("Use default compile options")
-    nativeCompileDefaults: Option[Boolean] = None //TODO does it even work when we default it to true while handling?
+    nativeCompileDefaults: Option[Boolean] = None, //TODO does it even work when we default it to true while handling?
+
+  @Group("Scala Native")
+  @HelpMessage("Embed resources into the Scala Native binary (can be read with the Java resources API)")
+    embedResources: Option[Boolean] = None
+
 )
 // format: on
 

modules/cli/src/main/scala/scala/cli/commands/Package.scala

@@ -22,6 +22,7 @@ import scala.build.errors.*
 import scala.build.interactive.InteractiveFileOps
 import scala.build.internal.Util.*
 import scala.build.internal.{Runner, ScalaJsLinkerConfig}
+import scala.build.internal.resource.NativeResourceMapper
 import scala.build.options.{PackageType, Platform}
 import scala.cli.CurrentParams
 import scala.cli.commands.OptionsHelper.*
@@ -912,7 +913,8 @@ object Package extends ScalaCommand[PackageOptions] with BuildCommandHelpers {
     logger: Logger
   ): Either[BuildException, Unit] = either {
 
-    val cliOptions = build.options.scalaNativeOptions.configCliOptions()
+    val cliOptions =
+      build.options.scalaNativeOptions.configCliOptions(!build.sources.resourceDirs.isEmpty)
 
     val setupPython = build.options.notForBloopOptions.doSetupPython.getOrElse(false)
     val pythonLdFlags =
@@ -940,10 +942,11 @@ object Package extends ScalaCommand[PackageOptions] with BuildCommandHelpers {
         nativeWorkDir
       )
 
-    if (cacheData.changed)
+    if (cacheData.changed) {
+      NativeResourceMapper.copyCFilesToScalaNativeDir(build, nativeWorkDir)
       Library.withLibraryJar(build, dest.last.stripSuffix(".jar")) { mainJar =>
 
-        val classpath = build.fullClassPath.map(_.toString) :+ mainJar.toString
+        val classpath = mainJar.toString +: build.artifacts.classPath.map(_.toString)
         val args =
           allCliOptions ++
             logger.scalaNativeCliInternalLoggerOptions ++
@@ -976,5 +979,6 @@ object Package extends ScalaCommand[PackageOptions] with BuildCommandHelpers {
         else
           throw new ScalaNativeBuildError
       }
+    }
   }
 }