Migrate to Scala 3.3.1 LTS

.scalafmt.conf

@@ -1,2 +1,2 @@
-version = "2.4.2"
+version = "3.8.0"
 align.tokens = []

build.sbt

@@ -1,12 +1,13 @@
 name := "Dahlia"
 version := "0.0.2"
 
-scalaVersion := "2.13.12"
+scalaVersion := "3.3.1"
 
 libraryDependencies ++= Seq(
-  "org.scalatest" %% "scalatest" % "3.0.8" % "test",
+  "org.scalatest" %% "scalatest" % "3.2.18" % "test",
+  "org.scalatest" %% "scalatest-funspec" % "3.2.18" % "test",
   "org.scala-lang.modules" %% "scala-parser-combinators" % "2.0.0",
-  "com.lihaoyi" %% "fastparse" % "2.3.0",
+  "com.lihaoyi" %% "fastparse" % "3.0.2",
   "com.github.scopt" %% "scopt" % "4.0.1",
   "com.outr" %% "scribe" % "3.5.5",
   "com.lihaoyi" %% "sourcecode" % "0.2.7"
@@ -16,26 +17,26 @@ scalacOptions ++= Seq(
   "-deprecation",
   "-unchecked",
   "-feature",
-  "-Ywarn-unused",
-  "-Ywarn-value-discard",
-  "-Xfatal-warnings"
+  "-Xfatal-warnings",
+  "-new-syntax",
+  "-indent"
 )
 
 // Reload changes to this file.
 Global / onChangedBuildSource := ReloadOnSourceChanges
 
 // Disable options in sbt console.
-scalacOptions in (Compile, console) ~=
+Compile / console / scalacOptions ~=
   (_ filterNot ((Set("-Xfatal-warnings", "-Ywarn-unused").contains(_))))
 
-testOptions in Test += Tests.Argument("-oD")
-parallelExecution in Test := false
-logBuffered in Test := false
+Test / testOptions += Tests.Argument("-oD")
+Test / parallelExecution := false
+Test / logBuffered := false
 
 /* Store commit hash information */
-resourceGenerators in Compile += Def.task {
+Compile / resourceGenerators += Def.task {
   import scala.sys.process._
-  val file = (resourceManaged in Compile).value / "version.properties"
+  val file = (Compile / resourceManaged).value / "version.properties"
   val gitHash = "git rev-parse --short HEAD".!!
   val gitDiff = "git diff --stat".!!
   val status = if (gitDiff.trim() != "") "dirty" else "clean"
@@ -48,11 +49,12 @@ resourceGenerators in Compile += Def.task {
 }
 
 /* sbt-assembly configuration: build an executable jar. */
-assemblyOption in assembly := (assemblyOption in assembly).value.copy(
-    prependShellScript = Some(sbtassembly.AssemblyPlugin.defaultShellScript)
-)
-assemblyJarName in assembly := "fuse.jar"
-test in assembly := {}
+//assembly / assemblyOption  := (assembly / assemblyOption).value.copy(
+//    prependShellScript = Some(sbtassembly.AssemblyPlugin.defaultShellScript)
+//)
+ThisBuild / assemblyPrependShellScript := Some(sbtassembly.AssemblyPlugin.defaultShellScript)
+assembly / assemblyJarName := "fuse.jar"
+assembly / test := {}
 
 /* Define task to download picojson headers */
 val getHeaders = taskKey[Unit]("Download header dependencies for runnable backend.")

fuse

@@ -1 +1 @@
-target/scala-2.13/fuse.jar
+target/scala-3.3.1/fuse.jar

project/assembly.sbt

@@ -1 +1 @@
-addSbtPlugin("com.eed3si9n" % "sbt-assembly" % "0.14.9")
+addSbtPlugin("com.eed3si9n" % "sbt-assembly" % "2.1.5")

src/main/scala/Compiler.scala

@@ -29,7 +29,7 @@ object Compiler {
     )
 
   def showDebug(ast: Prog, pass: String, c: Config): Unit = {
-    if (c.passDebug) {
+    if c.passDebug then {
       val top = ("=" * 15) + pass + ("=" * 15)
       println(top)
       println(Pretty.emitProg(ast)(c.logLevel == scribe.Level.Debug).trim)
@@ -49,7 +49,7 @@ object Compiler {
     showDebug(preAst, "Original", c)
 
     // Run pre transformers if lowering is enabled
-    val ast = if (c.enableLowering) {
+    val ast = if c.enableLowering then {
       preTransformers.foldLeft(preAst)({
         case (ast, (name, pass)) => {
           val newAst = pass.rewrite(ast)
@@ -115,7 +115,7 @@ object Compiler {
         err match {
           case _: Errors.TypeError => {
             s"[${red("Type error")}] ${err.getMessage}" +
-              (if (c.enableLowering)
+              (if c.enableLowering then
                  "\nDoes this program type check without the `--lower` flag? If it does, please report this as a bug: https://github.com/cucapra/dahlia/issues/new"
                else "")
           }
@@ -129,9 +129,7 @@ object Compiler {
       })
       .map(out => {
         // Get metadata about the compiler build.
-        val version = getClass.getResourceAsStream("/version.properties")
-        val meta = Source
-          .fromInputStream(version)
+        val meta = scala.io.Source.fromResource("version.properties")
           .getLines()
           .filter(l => l.trim != "")
           .mkString(", ")

src/main/scala/GenerateExec.scala

@@ -19,18 +19,18 @@ object GenerateExec {
 
 
   // Not the compiler directory, check if the fallback directory has been setup.
-  if (Files.exists(headerLocation) == false) {
+  if Files.exists(headerLocation) == false then {
     // Fallback for headers not setup. Unpack headers from JAR file.
     headerLocation = headerFallbackLocation
 
-    if (Files.exists(headerFallbackLocation) == false) {
+    if Files.exists(headerFallbackLocation) == false then {
       scribe.warn(
         s"Missing headers required for `fuse run`." +
           s" Unpacking from JAR file into $headerFallbackLocation."
       )
 
       val dir = Files.createDirectory(headerFallbackLocation)
-      for (header <- headers) {
+      for header <- headers do {
         val stream = getClass.getResourceAsStream(s"/headers/$header")
         val hdrSource = Source.fromInputStream(stream).toArray.map(_.toByte)
         Files.write(
@@ -57,8 +57,8 @@ object GenerateExec {
   ): Either[String, Int] = {
 
     // Make sure all headers are downloaded.
-    for (header <- headers) {
-      if (Files.exists(headerLocation.resolve(header)) == false) {
+    for header <- headers do {
+      if Files.exists(headerLocation.resolve(header)) == false then {
         throw HeaderMissing(header, headerLocation.toString)
       }
     }
@@ -75,7 +75,7 @@ object GenerateExec {
     scribe.info(cmd.mkString(" "))
     val status = cmd ! logger
 
-    if (status != 0) {
+    if status != 0 then {
       Left(s"Failed to generate the executable $out.\n${stderr}")
     } else {
       Right(status)

src/main/scala/Main.scala

@@ -8,8 +8,7 @@ import Compiler._
 import common.Logger
 import common.Configuration._
 
-object Main {
-
+object Main:
   // Command-line names for backends.
   val backends = Map(
     "vivado" -> Vivado,
@@ -23,9 +22,7 @@ object Main {
     "axi" -> Axi
   )
 
-  val version = getClass.getResourceAsStream("/version.properties")
-  val meta = Source
-    .fromInputStream(version)
+  val meta = scala.io.Source.fromResource("version.properties")
     .getLines()
     .filter(l => l.trim != "")
     .map(d => {
@@ -53,7 +50,7 @@ object Main {
     opt[String]('n', "name")
       .valueName("<kernel>")
       .validate(x =>
-        if (x.matches("[A-Za-z0-9_]+")) success
+        if x.matches("[A-Za-z0-9_]+") then success
         else failure("Kernel name should only contain alphanumerals and _")
       )
       .action((x, c) => c.copy(kernelName = x))
@@ -62,7 +59,7 @@ object Main {
     opt[String]('b', "backend")
       .valueName("<backend>")
       .validate(b =>
-        if (backends.contains(b)) success
+        if backends.contains(b) then success
         else
           failure(
             s"Invalid backend name. Valid backends are ${backends.keys.mkString(", ")}"
@@ -89,7 +86,7 @@ object Main {
 
     opt[String]("memory-interface")
       .validate(b =>
-        if (memoryInterfaces.contains(b)) success
+        if memoryInterfaces.contains(b) then success
         else
           failure(
             s"Invalid memory interface. Valid memory interfaces are ${memoryInterfaces.keys.mkString(", ")}"
@@ -117,7 +114,7 @@ object Main {
       )
   }
 
-  def runWithConfig(conf: Config): Either[String, Int] = {
+  def runWithConfig(conf: Config): Either[String, Int] =
     type ErrString = String
 
     val path = conf.srcFile.toPath
@@ -146,25 +143,17 @@ object Main {
         case _ => Right(0)
       }
     )
-
     status
-  }
-
-  def main(args: Array[String]): Unit = {
 
-    parser.parse(args, emptyConf) match {
-      case Some(conf) => {
+  def main(args: Array[String]): Unit =
+    parser.parse(args, emptyConf) match
+      case Some(conf) =>
         Logger.setLogLevel(conf.logLevel)
         val status = runWithConfig(conf)
         sys.exit(
           status.left
             .map(compileErr => { System.err.println(compileErr); 1 })
             .merge
         )
-      }
-      case None => {
+      case None =>
         sys.exit(1)
-      }
-    }
-  }
-}

src/main/scala/Parser.scala

@@ -11,27 +11,26 @@ import Configuration.stringToBackend
 import Utils.RichOption
 import CompilerError.BackendError
 
-case class Parser(input: String) {
+case class Parser(input: String):
 
   // Common surround expressions
   def braces[K: P, T](p: => P[T]): P[T] = P("{" ~/ p ~ "}")
   def brackets[K: P, T](p: => P[T]): P[T] = P("[" ~ p ~ "]")
   def angular[K: P, T](p: => P[T]): P[T] = P("<" ~/ p ~ ">")
   def parens[K: P, T](p: => P[T]): P[T] = P("(" ~/ p ~ ")")
 
-  def positioned[K: P, T <: PositionalWithSpan](p: => P[T]): P[T] = {
+  def positioned[K: P, T <: PositionalWithSpan](p: => P[T]): P[T] =
     P(Index ~ p ~ Index).map({
       case (index, t, end) => {
         val startPos = OffsetPosition(input, index)
         val out = t.setPos(startPos)
         val endPos = OffsetPosition(input, end)
-        if (startPos.line == endPos.line) {
+        if startPos.line == endPos.line then {
           out.setSpan(end - index)
         }
         out
       }
     })
-  }
 
   /*def notKws[K: P] = {
     import fastparse.NoWhitespace._
@@ -43,18 +42,16 @@ case class Parser(input: String) {
     ) ~ &(" "))).opaque("non reserved keywords")
   }*/
 
-  def kw[K: P](word: String): P[Unit] = {
+  def kw[K: P](word: String): P[Unit] =
     import fastparse.NoWhitespace._
     P(word ~ !CharsWhileIn("a-zA-Z0-9_"))
-  }
 
   // Basic atoms
-  def iden[K: P]: P[Id] = {
+  def iden[K: P]: P[Id] =
     import fastparse.NoWhitespace._
     positioned(P(CharIn("a-zA-Z_") ~ CharsWhileIn("a-zA-Z0-9_").?).!.map({
       case rest => Id(rest)
     }).opaque("Expected valid identifier"))
-  }
 
   def number[K: P]: P[Int] =
     P(CharIn("0-9").rep(1).!.map(_.toInt)).opaque("Expected positive number")
@@ -469,19 +466,12 @@ case class Parser(input: String) {
       })
     )
 
-  def parse(): Prog = {
-    fastparse.parse[Prog](input, prog(_)) match {
+  def parse(): Prog =
+    fastparse.parse[Prog](input, prog(_)) match
       case Parsed.Success(e, _) => e
-      case Parsed.Failure(_, index, extra) => {
+      case Parsed.Failure(_, index, extra) =>
         val traced = extra.trace()
         val loc = OffsetPosition(input, index)
         val msg = Errors.withPos(s"Expected ${traced.failure.label}", loc)
 
         throw Errors.ParserError(msg)
-      }
-      // XXX(rachit): Scala 2.13.4 complains that this pattern is not exhaustive.
-      // This is not true...
-      case _ => ???
-    }
-  }
-}

src/main/scala/Utils.scala

@@ -56,7 +56,7 @@ object Utils {
   }
 
   @inline def assertOrThrow[T <: Throwable](cond: Boolean, except: => T) = {
-    if (!cond) throw except
+    if !cond then throw except
   }
 
   @deprecated(

src/main/scala/backends/Backend.scala

@@ -9,7 +9,7 @@ import CompilerError.BackendError
 trait Backend {
 
   def emit(p: Syntax.Prog, c: Configuration.Config): String = {
-    if (c.header && (canGenerateHeader == false)) {
+    if c.header && (canGenerateHeader == false) then {
       throw BackendError(s"Backend $this does not support header generation.")
     }
     emitProg(p, c)

src/main/scala/backends/CppLike.scala

@@ -35,7 +35,7 @@ object Cpp {
       * Helper to generate a function call that might have a type parameter
       */
     def cCall(f: String, tParam: Option[Doc], args: Seq[Doc]): Doc = {
-      text(f) <> (if (tParam.isDefined) angles(tParam.get) else emptyDoc) <>
+      text(f) <> (if tParam.isDefined then angles(tParam.get) else emptyDoc) <>
         parens(commaSep(args))
     }
 
@@ -76,7 +76,7 @@ object Cpp {
       */
     def emitLet(let: CLet): Doc =
       emitDecl(let.id, let.typ.get) <>
-        (if (let.e.isDefined) space <> equal <+> emitExpr(let.e.get)
+        (if let.e.isDefined then space <> equal <+> emitExpr(let.e.get)
          else emptyDoc) <>
         semi
 
@@ -93,7 +93,7 @@ object Cpp {
       case EApp(fn, args) => fn <> parens(commaSep(args.map(emitExpr)))
       case EInt(v, base) => value(emitBaseInt(v, base))
       case ERational(d) => value(d)
-      case EBool(b) => value(if (b) 1 else 0)
+      case EBool(b) => value(if b then 1 else 0)
       case EVar(id) => value(id)
       case EBinop(op, e1, e2) => parens(e1 <+> text(op.toString) <+> e2)
       case EArrAccess(id, idxs) =>
@@ -116,7 +116,7 @@ object Cpp {
       */
     def emitRange(range: CRange): Doc = parens {
       val CRange(id, _, rev, s, e, _) = range
-      if (rev) {
+      if rev then {
         text("int") <+> id <+> equal <+> value(e - 1) <> semi <+>
         id <+> text(">=") <+> value(s) <> semi <+>
         id <> text("--")
@@ -167,7 +167,7 @@ object Cpp {
           )
           .getOrElse(emptyDoc)
 
-        if (entry) text("extern") <+> quote(text("C")) <+> scope(body)
+        if entry then text("extern") <+> quote(text("C")) <+> scope(body)
         else body
     }