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Diffstat (limited to 'core/src/main/scala/chisel3/experimental/dataview')
3 files changed, 477 insertions, 0 deletions
diff --git a/core/src/main/scala/chisel3/experimental/dataview/DataProduct.scala b/core/src/main/scala/chisel3/experimental/dataview/DataProduct.scala new file mode 100644 index 00000000..55dd8505 --- /dev/null +++ b/core/src/main/scala/chisel3/experimental/dataview/DataProduct.scala @@ -0,0 +1,72 @@ +// SPDX-License-Identifier: Apache-2.0 + +package chisel3.experimental.dataview + +import chisel3.experimental.BaseModule +import chisel3.{Data, getRecursiveFields} + +import scala.annotation.implicitNotFound + +/** Typeclass interface for getting elements of type [[Data]] + * + * This is needed for validating [[DataView]]s targeting type `A`. + * Can be thought of as "can be the Target of a DataView". + * + * Chisel provides some implementations in [[DataProduct$ object DataProduct]] that are available + * by default in the implicit scope. + * + * @tparam A Type that has elements of type [[Data]] + * @see [[https://www.chisel-lang.org/chisel3/docs/explanations/dataview#dataproduct Detailed Documentation]] + */ +@implicitNotFound("Could not find implicit value for DataProduct[${A}].\n" + + "Please see https://www.chisel-lang.org/chisel3/docs/explanations/dataview#dataproduct") +trait DataProduct[-A] { + /** Provides [[Data]] elements within some containing object + * + * @param a Containing object + * @param path Hierarchical path to current signal (for error reporting) + * @return Data elements and associated String paths (Strings for error reporting only!) + */ + def dataIterator(a: A, path: String): Iterator[(Data, String)] + + /** Returns a checker to test if the containing object contains a `Data` object + * @note Implementers may want to override if iterating on all `Data` is expensive for `A` and `A` + * will primarily be used in `PartialDataViews` + * @note The returned value is a function, not a true Set, but is describing the functionality of + * Set containment + * @param a Containing object + * @return A checker that itself returns True if a given `Data` is contained in `a` + * as determined by an `==` test + */ + def dataSet(a: A): Data => Boolean = dataIterator(a, "").map(_._1).toSet +} + +/** Encapsulating object for automatically provided implementations of [[DataProduct]] + * + * @note DataProduct implementations provided in this object are available in the implicit scope + */ +object DataProduct { + /** [[DataProduct]] implementation for [[Data]] */ + implicit val dataDataProduct: DataProduct[Data] = new DataProduct[Data] { + def dataIterator(a: Data, path: String): Iterator[(Data, String)] = + getRecursiveFields.lazily(a, path).iterator + } + + /** [[DataProduct]] implementation for [[BaseModule]] */ + implicit val userModuleDataProduct: DataProduct[BaseModule] = new DataProduct[BaseModule] { + def dataIterator(a: BaseModule, path: String): Iterator[(Data, String)] = { + a.getIds.iterator.flatMap { + case d: Data if d.getOptionRef.isDefined => // Using ref to decide if it's truly hardware in the module + Seq(d -> s"${path}.${d.instanceName}") + case b: BaseModule => dataIterator(b, s"$path.${b.instanceName}") + case _ => Seq.empty + } + } + // Overridden for performance + override def dataSet(a: BaseModule): Data => Boolean = { + val lastId = a._lastId // Not cheap to compute + // Return a function + e => e._id > a._id && e._id <= lastId + } + } +} diff --git a/core/src/main/scala/chisel3/experimental/dataview/DataView.scala b/core/src/main/scala/chisel3/experimental/dataview/DataView.scala new file mode 100644 index 00000000..caf004c2 --- /dev/null +++ b/core/src/main/scala/chisel3/experimental/dataview/DataView.scala @@ -0,0 +1,154 @@ +// SPDX-License-Identifier: Apache-2.0 + +package chisel3.experimental.dataview + +import chisel3._ +import chisel3.internal.sourceinfo.SourceInfo +import scala.reflect.runtime.universe.WeakTypeTag + +import annotation.implicitNotFound + + +/** Mapping between a target type `T` and a view type `V` + * + * Enables calling `.viewAs[T]` on instances of the target type. + * + * ==Detailed documentation== + * - [[https://www.chisel-lang.org/chisel3/docs/explanations/dataview Explanation]] + * - [[https://www.chisel-lang.org/chisel3/docs/cookbooks/dataview Cookbook]] + * + * @example {{{ + * class Foo(val w: Int) extends Bundle { + * val a = UInt(w.W) + * } + * class Bar(val w: Int) extends Bundle { + * val b = UInt(w.W) + * } + * // DataViews are created using factory methods in the companion object + * implicit val view = DataView[Foo, Bar]( + * // The first argument is a function constructing a Foo from a Bar + * foo => new Bar(foo.w) + * // The remaining arguments are a variable number of field pairings + * _.a -> _.b + * ) + * }}} + * + * @tparam T Target type (must have an implementation of [[DataProduct]]) + * @tparam V View type + * @see [[DataView$ object DataView]] for factory methods + * @see [[PartialDataView object PartialDataView]] for defining non-total `DataViews` + */ +@implicitNotFound("Could not find implicit value for DataView[${T}, ${V}].\n" + + "Please see https://www.chisel-lang.org/chisel3/docs/explanations/dataview") +sealed class DataView[T : DataProduct, V <: Data] private[chisel3] ( + /** Function constructing an object of the View type from an object of the Target type */ + private[chisel3] val mkView: T => V, + /** Function that returns corresponding fields of the target and view */ + private[chisel3] val mapping: (T, V) => Iterable[(Data, Data)], + // Aliasing this with a def below to make the ScalaDoc show up for the field + _total: Boolean +)( + implicit private[chisel3] val sourceInfo: SourceInfo +) { + /** Indicates if the mapping contains every field of the target */ + def total: Boolean = _total + + override def toString: String = { + val base = sourceInfo.makeMessage(x => x) + val loc = if (base.nonEmpty) base else "@unknown" + val name = if (total) "DataView" else "PartialDataView" + s"$name(defined $loc)" + } + + /** Compose two `DataViews` together to construct a view from the target of this `DataView` to the + * view type of the second `DataView` + * + * @param g a DataView from `V` to new view-type `V2` + * @tparam V2 View type of `DataView` `g` + * @return a new `DataView` from the original `T` to new view-type `V2` + */ + def andThen[V2 <: Data](g: DataView[V, V2])(implicit sourceInfo: SourceInfo): DataView[T, V2] = { + val self = this + // We have to pass the DataProducts and DataViews manually to .viewAs below + val tdp = implicitly[DataProduct[T]] + val vdp = implicitly[DataProduct[V]] + new DataView[T, V2]( + t => g.mkView(mkView(t)), + { case (t, v2) => List(t.viewAs[V](tdp, self).viewAs[V2](vdp, g) -> v2) }, + this.total && g.total + ) { + override def toString: String = s"$self andThen $g" + } + } +} + +/** Factory methods for constructing [[DataView]]s, see class for example use */ +object DataView { + + /** Default factory method, alias for [[pairs]] */ + def apply[T : DataProduct, V <: Data](mkView: T => V, pairs: ((T, V) => (Data, Data))*)(implicit sourceInfo: SourceInfo): DataView[T, V] = + DataView.pairs(mkView, pairs: _*) + + /** Construct [[DataView]]s with pairs of functions from the target and view to corresponding fields */ + def pairs[T : DataProduct, V <: Data](mkView: T => V, pairs: ((T, V) => (Data, Data))*)(implicit sourceInfo: SourceInfo): DataView[T, V] = + mapping(mkView: T => V, swizzle(pairs)) + + /** More general factory method for complex mappings */ + def mapping[T : DataProduct, V <: Data](mkView: T => V, mapping: (T, V) => Iterable[(Data, Data)])(implicit sourceInfo: SourceInfo): DataView[T, V] = + new DataView[T, V](mkView, mapping, _total = true) + + /** 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) + } + } + + private[dataview] def swizzle[A, B, C, D](fs: Iterable[(A, B) => (C, D)]): (A, B) => Iterable[(C, D)] = { + case (a, b) => fs.map(f => f(a, b)) + } + + private 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) + } + + /** All Chisel Data are viewable as their own type */ + implicit def identityView[A <: Data](implicit sourceInfo: SourceInfo): DataView[A, A] = + DataView[A, A](chiselTypeOf.apply, { case (x, y) => (x, y) }) +} + +/** Factory methods for constructing non-total [[DataView]]s */ +object PartialDataView { + + /** Default factory method, alias for [[pairs]] */ + def apply[T: DataProduct, V <: Data](mkView: T => V, pairs: ((T, V) => (Data, Data))*)(implicit sourceInfo: SourceInfo): DataView[T, V] = + PartialDataView.pairs(mkView, pairs: _*) + + /** Construct [[DataView]]s with pairs of functions from the target and view to corresponding fields */ + def pairs[T: DataProduct, V <: Data](mkView: T => V, pairs: ((T, V) => (Data, Data))*)(implicit sourceInfo: SourceInfo): DataView[T, V] = + mapping(mkView, DataView.swizzle(pairs)) + + /** More general factory method for complex mappings */ + def mapping[T: DataProduct, V <: Data](mkView: T => V, mapping: (T, V) => Iterable[(Data, Data)])(implicit sourceInfo: SourceInfo): DataView[T, V] = + new DataView[T, V](mkView, mapping, _total = false) +} diff --git a/core/src/main/scala/chisel3/experimental/dataview/package.scala b/core/src/main/scala/chisel3/experimental/dataview/package.scala new file mode 100644 index 00000000..1acf43e1 --- /dev/null +++ b/core/src/main/scala/chisel3/experimental/dataview/package.scala @@ -0,0 +1,251 @@ +// SPDX-License-Identifier: Apache-2.0 + +package chisel3.experimental + +import chisel3._ +import chisel3.internal._ +import chisel3.internal.sourceinfo.SourceInfo + +import scala.annotation.{implicitNotFound, tailrec} +import scala.collection.mutable +import scala.collection.immutable.LazyList // Needed for 2.12 alias + +package object dataview { + case class InvalidViewException(message: String) extends ChiselException(message) + + /** Provides `viewAs` for types that have an implementation of [[DataProduct]] + * + * Calling `viewAs` also requires an implementation of [[DataView]] for the target type + */ + implicit class DataViewable[T](target: T) { + def viewAs[V <: Data](implicit dataproduct: DataProduct[T], dataView: DataView[T, V]): V = { + // TODO put a try catch here for ExpectedHardwareException and perhaps others + // It's likely users will accidentally use chiselTypeOf or something that may error, + // The right thing to use is DataMirror...chiselTypeClone because of composition with DataView.andThen + // Another option is that .andThen could give a fake binding making chiselTypeOfs in the user code safe + val result: V = dataView.mkView(target) + requireIsChiselType(result, "viewAs") + + doBind(target, result, dataView) + + // Setting the parent marks these Data as Views + result.setAllParents(Some(ViewParent)) + // The names of views do not matter except for when a view is annotated. For Views that correspond + // To a single Data, we just forward the name of the Target. For Views that correspond to more + // than one Data, we return this assigned name but rename it in the Convert stage + result.forceName(None, "view", Builder.viewNamespace) + result + } + } + + // This private type alias lets us provide a custom error message for misuing the .viewAs for upcasting Bundles + @implicitNotFound("${A} is not a subtype of ${B}! Did you mean .viewAs[${B}]? " + + "Please see https://www.chisel-lang.org/chisel3/docs/cookbooks/dataview") + private type SubTypeOf[A, B] = A <:< B + + /** Provides `viewAsSupertype` for subclasses of [[Bundle]] */ + implicit class BundleUpcastable[T <: Bundle](target: T) { + /** View a [[Bundle]] or [[Record]] as a parent type (upcast) */ + def viewAsSupertype[V <: Bundle](proto: V)(implicit ev: SubTypeOf[T, V], sourceInfo: SourceInfo): V = { + implicit val dataView = PartialDataView.mapping[T, V](_ => proto, { + case (a, b) => + val aElts = a.elements + val bElts = b.elements + val bKeys = bElts.keySet + val keys = aElts.keysIterator.filter(bKeys.contains) + keys.map(k => aElts(k) -> bElts(k)).toSeq + }) + target.viewAs[V] + } + } + + private def nonTotalViewException(dataView: DataView[_, _], target: Any, view: Data, targetFields: Seq[String], viewFields: Seq[String]) = { + def missingMsg(name: String, fields: Seq[String]): Option[String] = { + val str = fields.mkString(", ") + fields.size match { + case 0 => None + case 1 => Some(s"$name field '$str' is missing") + case _ => Some(s"$name fields '$str' are missing") + } + } + val vs = missingMsg("view", viewFields) + val ts = missingMsg("target", targetFields) + val reasons = (ts ++ vs).mkString(" and ").capitalize + val suggestion = if (ts.nonEmpty) "\n If the view *should* be non-total, try a 'PartialDataView'." else "" + val msg = s"Viewing $target as $view is non-Total!\n $reasons.\n DataView used is $dataView.$suggestion" + throw InvalidViewException(msg) + } + + // TODO should this be moved to class Aggregate / can it be unified with Aggregate.bind? + private def doBind[T : DataProduct, V <: Data](target: T, view: V, dataView: DataView[T, V]): Unit = { + val mapping = dataView.mapping(target, view) + val total = dataView.total + // Lookups to check the mapping results + val viewFieldLookup: Map[Data, String] = getRecursiveFields(view, "_").toMap + val targetContains: Data => Boolean = implicitly[DataProduct[T]].dataSet(target) + + // Resulting bindings for each Element of the View + val childBindings = + new mutable.HashMap[Data, mutable.ListBuffer[Element]] ++ + viewFieldLookup.view + .collect { case (elt: Element, _) => elt } + .map(_ -> new mutable.ListBuffer[Element]) + + def viewFieldName(d: Data): String = + viewFieldLookup.get(d).map(_ + " ").getOrElse("") + d.toString + + // Helper for recording the binding of each + def onElt(te: Element, ve: Element): Unit = { + // TODO can/should we aggregate these errors? + def err(name: String, arg: Data) = + throw InvalidViewException(s"View mapping must only contain Elements within the $name, got $arg") + + // The elements may themselves be views, look through the potential chain of views for the Elements + // that are actually members of the target or view + val tex = unfoldView(te).find(targetContains).getOrElse(err("Target", te)) + val vex = unfoldView(ve).find(viewFieldLookup.contains).getOrElse(err("View", ve)) + + if (tex.getClass != vex.getClass) { + val fieldName = viewFieldName(vex) + throw InvalidViewException(s"Field $fieldName specified as view of non-type-equivalent value $tex") + } + // View width must be unknown or match target width + if (vex.widthKnown && vex.width != tex.width) { + def widthAsString(x: Element) = x.widthOption.map("<" + _ + ">").getOrElse("<unknown>") + val fieldName = viewFieldName(vex) + val vwidth = widthAsString(vex) + val twidth = widthAsString(tex) + throw InvalidViewException(s"View field $fieldName has width ${vwidth} that is incompatible with target value $tex's width ${twidth}") + } + childBindings(vex) += tex + } + + mapping.foreach { + // Special cased because getMatchedFields checks typeEquivalence on Elements (and is used in Aggregate path) + // Also saves object allocations on common case of Elements + case (ae: Element, be: Element) => onElt(ae, be) + + case (aa: Aggregate, ba: Aggregate) => + if (!ba.typeEquivalent(aa)) { + val fieldName = viewFieldLookup(ba) + throw InvalidViewException(s"field $fieldName specified as view of non-type-equivalent value $aa") + } + getMatchedFields(aa, ba).foreach { + case (aelt: Element, belt: Element) => onElt(aelt, belt) + case _ => // Ignore matching of Aggregates + } + } + + // Errors in totality of the View, use var List to keep fast path cheap (no allocation) + var viewNonTotalErrors: List[Data] = Nil + var targetNonTotalErrors: List[String] = Nil + + val targetSeen: Option[mutable.Set[Data]] = if (total) Some(mutable.Set.empty[Data]) else None + + val resultBindings = childBindings.map { case (data, targets) => + val targetsx = targets match { + case collection.Seq(target: Element) => target + case collection.Seq() => + viewNonTotalErrors = data :: viewNonTotalErrors + data.asInstanceOf[Element] // Return the Data itself, will error after this map, cast is safe + case x => + throw InvalidViewException(s"Got $x, expected Seq(_: Direct)") + } + // TODO record and report aliasing errors + targetSeen.foreach(_ += targetsx) + data -> targetsx + }.toMap + + // Check for totality of Target + targetSeen.foreach { seen => + val lookup = implicitly[DataProduct[T]].dataIterator(target, "_") + for (missed <- lookup.collect { case (d: Element, name) if !seen(d) => name }) { + targetNonTotalErrors = missed :: targetNonTotalErrors + } + } + if (viewNonTotalErrors != Nil || targetNonTotalErrors != Nil) { + val viewErrors = viewNonTotalErrors.map(f => viewFieldLookup.getOrElse(f, f.toString)) + nonTotalViewException(dataView, target, view, targetNonTotalErrors, viewErrors) + } + + view match { + case elt: Element => view.bind(ViewBinding(resultBindings(elt))) + case agg: Aggregate => + // We record total Data mappings to provide a better .toTarget + val topt = target match { + case d: Data if total => Some(d) + case _ => + // Record views that don't have the simpler .toTarget for later renaming + Builder.unnamedViews += view + None + } + // TODO We must also record children as unnamed, some could be namable but this requires changes to the Binding + getRecursiveFields.lazily(view, "_").foreach { + case (agg: Aggregate, _) if agg != view => + Builder.unnamedViews += agg + case _ => // Do nothing + } + agg.bind(AggregateViewBinding(resultBindings, topt)) + } + } + + // Traces an Element that may (or may not) be a view until it no longer maps + // Inclusive of the argument + private def unfoldView(elt: Element): LazyList[Element] = { + def rec(e: Element): LazyList[Element] = e.topBindingOpt match { + case Some(ViewBinding(target)) => target #:: rec(target) + case Some(AggregateViewBinding(mapping, _)) => + val target = mapping(e) + target #:: rec(target) + case Some(_) | None => LazyList.empty + } + elt #:: rec(elt) + } + + // Safe for all Data + private[chisel3] def isView(d: Data): Boolean = d._parent.contains(ViewParent) + + /** Turn any [[Element]] that could be a View into a concrete Element + * + * This is the fundamental "unwrapping" or "tracing" primitive operation for handling Views within + * Chisel. + */ + private[chisel3] def reify(elt: Element): Element = + reify(elt, elt.topBinding) + + /** Turn any [[Element]] that could be a View into a concrete Element + * + * This is the fundamental "unwrapping" or "tracing" primitive operation for handling Views within + * Chisel. + */ + @tailrec private[chisel3] def reify(elt: Element, topBinding: TopBinding): Element = + topBinding match { + case ViewBinding(target) => reify(target, elt.topBinding) + case _ => elt + } + + /** Determine the target of a View if it is a single Target + * + * @note An Aggregate may be a view of unrelated [[Data]] (eg. like a Seq or tuple) and thus this + * there is no single Data representing the Target and this function will return None + * @return The single Data target of this view or None if a single Data doesn't exist + */ + private[chisel3] def reifySingleData(data: Data): Option[Data] = { + val candidate: Option[Data] = + data.binding.collect { // First check if this is a total mapping of an Aggregate + case AggregateViewBinding(_, Some(t)) => t + }.orElse { // Otherwise look via top binding + data.topBindingOpt match { + case None => None + case Some(ViewBinding(target)) => Some(target) + case Some(AggregateViewBinding(lookup, _)) => lookup.get(data) + case Some(_) => None + } + } + candidate.flatMap { d => + // Candidate may itself be a view, keep tracing in those cases + if (isView(d)) reifySingleData(d) else Some(d) + } + } + +} |