[Scala3] Scala2 compatibility changes (#4483)

Author: adkian-sifive

core/src/main/scala-2/chisel3/Aggregate.scala

@@ -74,6 +74,8 @@ sealed class Vec[T <: Data] private[chisel3] (gen: => T, length: Int)
   ): T = _reduceTreeImpl(redOp, layerOp)
 }
 
+object Vec extends VecFactory
+
 object VecInit extends VecInitImpl with SourceInfoDoc {
 
   /** Creates a new [[Vec]] composed of elements of the input Seq of [[Data]]

core/src/main/scala-2/chisel3/Bits.scala

@@ -282,6 +282,8 @@ sealed abstract class Bits(private[chisel3] val width: Width) extends BitsImpl w
   def do_##(that: Bits)(implicit sourceInfo: SourceInfo): UInt = _impl_##(that)
 }
 
+object Bits extends UIntFactory
+
 /** A data type for unsigned integers, represented as a binary bitvector. Defines arithmetic operations between other
   * integer types.
   *
@@ -553,6 +555,8 @@ sealed class UInt private[chisel3] (width: Width) extends Bits(width) with UIntI
   override def do_asSInt(implicit sourceInfo: SourceInfo): SInt = _asSIntImpl
 }
 
+object UInt extends UIntFactory
+
 /** A data type for signed integers, represented as a binary bitvector. Defines arithmetic operations between other
   * integer types.
   *
@@ -734,6 +738,8 @@ sealed class SInt private[chisel3] (width: Width) extends Bits(width) with SIntI
   override def do_asSInt(implicit sourceInfo: SourceInfo): SInt = _asSIntImpl
 }
 
+object SInt extends SIntFactory
+
 sealed trait Reset extends ResetImpl with ToBoolable {
 
   /** Casts this $coll to an [[AsyncReset]] */
@@ -876,3 +882,5 @@ sealed class Bool() extends UInt(1.W) with BoolImpl with Reset {
   /** @group SourceInfoTransformMacro */
   def do_asAsyncReset(implicit sourceInfo: SourceInfo): AsyncReset = _asAsyncResetImpl
 }
+
+object Bool extends BoolFactory

core/src/main/scala/chisel3/Printf.scala renamed to core/src/main/scala-2/chisel3/Printf.scala

@@ -13,33 +13,11 @@ import scala.language.experimental.macros
   *
   * See apply methods for use
   */
-object printf {
+object printf extends PrintfImpl {
 
   /** Named class for [[printf]]s. */
   final class Printf private[chisel3] (val pable: Printable) extends VerificationStatement
 
-  /** Helper for packing escape characters */
-  private[chisel3] def format(formatIn: String): String = {
-    require(formatIn.forall(c => c.toInt > 0 && c.toInt < 128), "format strings must comprise non-null ASCII values")
-    def escaped(x: Char) = {
-      require(x.toInt >= 0, s"char ${x} to Int ${x.toInt} must be >= 0")
-      if (x == '"' || x == '\\') {
-        s"\\${x}"
-      } else if (x == '\n') {
-        "\\n"
-      } else if (x == '\t') {
-        "\\t"
-      } else {
-        require(
-          x.toInt >= 32,
-          s"char ${x} to Int ${x.toInt} must be >= 32"
-        ) // TODO \xNN once FIRRTL issue #59 is resolved
-        x
-      }
-    }
-    formatIn.map(escaped).mkString("")
-  }
-
   /** Prints a message in simulation
     *
     * Prints a message every cycle. If defined within the scope of a [[when]] block, the message

core/src/main/scala/chisel3/VerificationStatement.scala renamed to core/src/main/scala-2/chisel3/VerificationStatement.scala

@@ -3,18 +3,9 @@
 package chisel3
 
 import chisel3.experimental.{BaseModule, SourceInfo}
-import chisel3.internal._
-import chisel3.internal.Builder.pushCommand
-import chisel3.internal.firrtl.ir._
-import chisel3.layer.block
 
 import scala.language.experimental.macros
 
-/** Base class for all verification statements: Assert, Assume, Cover, Stop and Printf. */
-abstract class VerificationStatement extends NamedComponent {
-  _parent.foreach(_.addId(this))
-}
-
 /** Scaladoc information for internal verification statement macros
   * that are used in objects assert, assume and cover.
   *
@@ -29,7 +20,7 @@ abstract class VerificationStatement extends NamedComponent {
   */
 trait VerifPrintMacrosDoc
 
-object assert extends VerifPrintMacrosDoc {
+object assert extends assertImpl with VerifPrintMacrosDoc {
 
   /** Named class for assertions. */
   final class Assert private[chisel3] () extends VerificationStatement
@@ -79,15 +70,9 @@ object assert extends VerifPrintMacrosDoc {
 
   def apply(cond: Bool)(implicit sourceInfo: SourceInfo): Assert =
     macro VerifStmtMacrosCompat.assert._applyMacroWithNoMessage
-
-  /** An elaboration-time assertion. Calls the built-in Scala assert function. */
-  def apply(cond: Boolean, message: => String): Unit = Predef.assert(cond, message)
-
-  /** An elaboration-time assertion. Calls the built-in Scala assert function. */
-  def apply(cond: Boolean): Unit = Predef.assert(cond, "")
 }
 
-object assume extends VerifPrintMacrosDoc {
+object assume extends assumeImpl with VerifPrintMacrosDoc {
 
   /** Named class for assumptions. */
   final class Assume private[chisel3] () extends VerificationStatement
@@ -141,12 +126,6 @@ object assume extends VerifPrintMacrosDoc {
 
   def apply(cond: Bool)(implicit sourceInfo: SourceInfo): Assume =
     macro VerifStmtMacrosCompat.assume._applyMacroWithNoMessage
-
-  /** An elaboration-time assumption. Calls the built-in Scala assume function. */
-  def apply(cond: Boolean, message: => String): Unit = Predef.assume(cond, message)
-
-  /** An elaboration-time assumption. Calls the built-in Scala assume function. */
-  def apply(cond: Boolean): Unit = Predef.assume(cond, "")
 }
 
 object cover extends VerifPrintMacrosDoc {
@@ -171,37 +150,3 @@ object cover extends VerifPrintMacrosDoc {
   def apply(cond: Bool)(implicit sourceInfo: SourceInfo): Cover =
     macro VerifStmtMacrosCompat.cover._applyMacroWithNoMessage
 }
-
-object stop {
-
-  /** Terminate execution, indicating success and printing a message.
-    *
-    * @param message a message describing why simulation was stopped
-    */
-  def apply(message: String)(implicit sourceInfo: SourceInfo): Stop = buildStopCommand(Some(PString(message)))
-
-  /** Terminate execution, indicating success and printing a message.
-    *
-    * @param message a printable describing why simulation was stopped
-    */
-  def apply(message: Printable)(implicit sourceInfo: SourceInfo): Stop = buildStopCommand(Some(message))
-
-  /** Terminate execution, indicating success.
-    */
-  def apply()(implicit sourceInfo: SourceInfo): Stop = buildStopCommand(None)
-
-  /** Named class for [[stop]]s. */
-  final class Stop private[chisel3] () extends VerificationStatement
-
-  private def buildStopCommand(message: Option[Printable])(implicit sourceInfo: SourceInfo): Stop = {
-    val stopId = new Stop()
-    block(layers.Verification, skipIfAlreadyInBlock = true, skipIfLayersEnabled = true) {
-      message.foreach(Printable.checkScope(_))
-      when(!Module.reset.asBool) {
-        message.foreach(PrintfMacrosCompat.printfWithoutReset(_))
-        pushCommand(Stop(stopId, sourceInfo, Builder.forcedClock.ref, 0))
-      }
-    }
-    stopId
-  }
-}

core/src/main/scala-2/chisel3/experimental/dataview/ChiselSubtypeOf.scala

@@ -28,6 +28,7 @@ import scala.reflect.macros.blackbox.Context
 sealed trait ChiselSubtypeOf[A, B]
 
 object ChiselSubtypeOf {
+  // TODO return an empty tree here instead of a quasiquote for scala3 compatibility
   def genChiselSubtypeOf[A: c.WeakTypeTag, B: c.WeakTypeTag](c: Context): c.Tree = {
     import c.universe._
 

core/src/main/scala-2/chisel3/experimental/dataview/InvertibleDataView.scala

@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: Apache-2.0
+
+package chisel3.experimental.dataview
+
+import chisel3._
+import scala.reflect.runtime.universe.WeakTypeTag
+
+private[chisel3] trait InvertibleDataView {
+  def swapArgs[A, B, C, D](f: (A, B) => Iterable[(C, D)]): (B, A) => Iterable[(D, C)] = {
+    case (b, a) => f(a, b).map(_.swap)
+  }
+
+  /** Provides `invert` for invertible [[DataView]]s
+    *
+    * This must be done as an extension method because it applies an addition constraint on the `Target`
+    * type parameter, namely that it must be a subtype of [[Data]].
+    *
+    * @note [[PartialDataView]]s are **not** invertible and will result in an elaboration time exception
+    */
+  implicit class InvertibleDataView[T <: Data: WeakTypeTag, V <: Data: WeakTypeTag](view: DataView[T, V]) {
+    def invert(mkView: V => T): DataView[V, T] = {
+      // It would've been nice to make this a compiler error, but it's unclear how to make that work.
+      // We tried having separate TotalDataView and PartialDataView and only defining inversion for
+      // TotalDataView. For some reason, implicit resolution wouldn't invert TotalDataViews. This is
+      // probably because it was looking for the super-type DataView and since invertDataView was
+      // only defined on TotalDataView, it wasn't included in implicit resolution. Thus we end up
+      // with a runtime check.
+      if (!view.total) {
+        val tt = implicitly[WeakTypeTag[T]].tpe
+        val vv = implicitly[WeakTypeTag[V]].tpe
+        val msg = s"Cannot invert '$view' as it is non-total.\n  Try providing a DataView[$vv, $tt]." +
+          s"\n  Please see https://www.chisel-lang.org/chisel3/docs/explanations/dataview."
+        throw InvalidViewException(msg)
+      }
+      implicit val sourceInfo = view.sourceInfo
+      new DataView[V, T](mkView, swapArgs(view.mapping), view.total)
+    }
+  }
+}

core/src/main/scala-2/chisel3/experimental/hierarchy/HierarchyPackage.scala

@@ -0,0 +1,45 @@
+package chisel3.experimental
+
+/** Classes or traits which will be used with the [[Definition]] + [[Instance]] api should be marked
+  * with the [[instantiable]] annotation at the class/trait definition.
+  *
+  * @example {{{
+  * @instantiable
+  * class MyModule extends Module {
+  *   ...
+  * }
+  *
+  * val d = Definition(new MyModule)
+  * val i0 = Instance(d)
+  * val i1 = Instance(d)
+  * }}}
+  */
+class instantiable extends chisel3.internal.instantiable
+
+/** Classes marked with [[instantiable]] can have their vals marked with the [[public]] annotation to
+  * enable accessing these values from a [[Definition]] or [[Instance]] of the class.
+  *
+  * Only vals of the the following types can be marked [[public]]:
+  *   1. IsInstantiable
+  *   2. IsLookupable
+  *   3. Data
+  *   4. BaseModule
+  *   5. Iterable/Option containing a type that meets these requirements
+  *   6. Basic type like String, Int, BigInt etc.
+  *
+  * @example {{{
+  * @instantiable
+  * class MyModule extends Module {
+  *   @public val in = IO(Input(UInt(3.W)))
+  *   @public val out = IO(Output(UInt(3.W)))
+  *   ..
+  * }
+  *
+  * val d = Definition(new MyModule)
+  * val i0 = Instance(d)
+  * val i1 = Instance(d)
+  *
+  * i1.in := i0.out
+  * }}}
+  */
+class public extends chisel3.internal.public

core/src/main/scala-2/chisel3/experimental/hierarchy/Instantiate.scala

@@ -54,13 +54,13 @@ object Instantiate extends InstantiateImpl {
     f:    K => A
   )(
     implicit sourceInfo: SourceInfo
-  ): Instance[A] = _instanceImpl(args, f)
+  ): Instance[A] = _instanceImpl(args, f, implicitly[ru.WeakTypeTag[A]])
 
   /** This is not part of the public API, do not call directly! */
   def _definition[K, A <: BaseModule: ru.WeakTypeTag](
     args: K,
     f:    K => A
-  ): Definition[A] = _definitionImpl(args, f)
+  ): Definition[A] = _definitionImpl(args, f, implicitly[ru.WeakTypeTag[A]])
 
   private object internal {
 

core/src/main/scala/chisel3/internal/SourceInfoFileResolver.scala renamed to core/src/main/scala-2/chisel3/internal/SourceInfoFileResolver.scala

@@ -5,10 +5,12 @@ package chisel3.internal.sourceinfo
 import scala.language.experimental.macros
 import scala.reflect.macros.blackbox.Context
 
+import chisel3.internal.sourceinfo.SourceInfoFileResolver
+
 /** Provides a macro that returns the source information at the invocation point.
   */
 @deprecated("Public APIs in chisel3.internal are deprecated", "Chisel 3.6")
-object SourceInfoMacro {
+private[chisel3] object SourceInfoMacro {
   def generate_source_info(c: Context): c.Tree = {
     import c.universe._
     val p = c.enclosingPosition