From 164490c8fbf132ca65644d05d6ff8d0d7a3beb20 Mon Sep 17 00:00:00 2001 From: Adam Izraelevitz Date: Wed, 29 Jul 2020 20:48:31 -0700 Subject: Improved Chisel Naming via Compiler Plugins + Prefixing (#1448) Added prefixing and a compiler plugin to improve naming. Only works for Scala 2.12 and above. Co-authored-by: Jack Koenig --- plugin/src/main/resources/scalac-plugin.xml | 4 + .../scala-2.12/chisel3/plugin/ChiselPlugin.scala | 139 +++++++++++++++++++++ 2 files changed, 143 insertions(+) create mode 100644 plugin/src/main/resources/scalac-plugin.xml create mode 100644 plugin/src/main/scala-2.12/chisel3/plugin/ChiselPlugin.scala (limited to 'plugin') diff --git a/plugin/src/main/resources/scalac-plugin.xml b/plugin/src/main/resources/scalac-plugin.xml new file mode 100644 index 00000000..b2b44fc6 --- /dev/null +++ b/plugin/src/main/resources/scalac-plugin.xml @@ -0,0 +1,4 @@ + + chiselplugin + chisel3.plugin.ChiselPlugin + diff --git a/plugin/src/main/scala-2.12/chisel3/plugin/ChiselPlugin.scala b/plugin/src/main/scala-2.12/chisel3/plugin/ChiselPlugin.scala new file mode 100644 index 00000000..785a253d --- /dev/null +++ b/plugin/src/main/scala-2.12/chisel3/plugin/ChiselPlugin.scala @@ -0,0 +1,139 @@ +// See LICENSE for license details. + +package chisel3.plugin + +import scala.tools.nsc +import nsc.{Global, Phase} +import nsc.plugins.Plugin +import nsc.plugins.PluginComponent +import scala.reflect.internal.Flags +import scala.tools.nsc.transform.TypingTransformers + +// The plugin to be run by the Scala compiler during compilation of Chisel code +class ChiselPlugin(val global: Global) extends Plugin { + val name = "chiselplugin" + val description = "Plugin for Chisel 3 Hardware Description Language" + val components = List[PluginComponent](new ChiselComponent(global)) +} + +// The component of the chisel plugin. Not sure exactly what the difference is between +// a Plugin and a PluginComponent. +class ChiselComponent(val global: Global) extends PluginComponent with TypingTransformers { + import global._ + val runsAfter = List[String]("typer") + override val runsRightAfter: Option[String] = Some("typer") + val phaseName: String = "chiselcomponent" + def newPhase(_prev: Phase): ChiselComponentPhase = new ChiselComponentPhase(_prev) + class ChiselComponentPhase(prev: Phase) extends StdPhase(prev) { + override def name: String = phaseName + def apply(unit: CompilationUnit): Unit = { + // This plugin doesn't work on Scala 2.11. Rather than complicate the sbt build flow, + // instead we just check the version and if its an early Scala version, the plugin does nothing + if(scala.util.Properties.versionNumberString.split('.')(1).toInt >= 12) { + unit.body = new MyTypingTransformer(unit).transform(unit.body) + } + } + } + + class MyTypingTransformer(unit: CompilationUnit) + extends TypingTransformer(unit) { + + // Determines if the chisel plugin should match on this type + def shouldMatch(q: Type, bases: Seq[Tree]): Boolean = { + + // If subtype of Data or BaseModule, its a match! + def terminate(t: Type): Boolean = bases.exists { base => t <:< inferType(base) } + + // Recurse through subtype hierarchy finding containers + // Seen is only updated when we recurse into type parameters, thus it is typically small + def recShouldMatch(s: Type, seen: Set[Type]): Boolean = { + def outerMatches(t: Type): Boolean = { + val str = t.toString + str.startsWith("Option[") || str.startsWith("Iterable[") + } + if (terminate(s)) { + true + } else if (seen.contains(s)) { + false + } else if (outerMatches(s)) { + // These are type parameters, loops *are* possible here + recShouldMatch(s.typeArgs.head, seen + s) + } else { + // This is the standard inheritance hierarchy, Scalac catches loops here + s.parents.exists( p => recShouldMatch(p, seen) ) + } + } + + // If doesn't match container pattern, exit early + def earlyExit(t: Type): Boolean = { + !(t.matchesPattern(inferType(tq"Iterable[_]")) || t.matchesPattern(inferType(tq"Option[_]"))) + } + + // First check if a match, then check early exit, then recurse + if(terminate(q)){ + true + } else if(earlyExit(q)) { + false + } else { + recShouldMatch(q, Set.empty) + } + } + + // Given a type tree, infer the type and return it + def inferType(t: Tree): Type = localTyper.typed(t, nsc.Mode.TYPEmode).tpe + + // Indicates whether a ValDef is properly formed to get name + def okVal(dd: ValDef, bases: Tree*): Boolean = { + + // These were found through trial and error + def okFlags(mods: Modifiers): Boolean = { + val badFlags = Set( + Flag.PARAM, + Flag.SYNTHETIC, + Flag.DEFERRED, + Flags.TRIEDCOOKING, + Flags.CASEACCESSOR, + Flags.PARAMACCESSOR + ) + badFlags.forall{ x => !mods.hasFlag(x)} + } + + // Ensure expression isn't null, as you can't call `null.autoName("myname")` + val isNull = dd.rhs match { + case Literal(Constant(null)) => true + case _ => false + } + okFlags(dd.mods) && shouldMatch(inferType(dd.tpt), bases) && !isNull && dd.rhs != EmptyTree + } + + // Whether this val is directly enclosed by a Bundle type + def inBundle(dd: ValDef): Boolean = { + dd.symbol.logicallyEnclosingMember.thisType <:< inferType(tq"chisel3.Bundle") + } + + // Method called by the compiler to modify source tree + override def transform(tree: Tree): Tree = tree match { + // If a Data and in a Bundle, just get the name but not a prefix + case dd @ ValDef(mods, name, tpt, rhs) if okVal(dd, tq"chisel3.Data") && inBundle(dd) => + val TermName(str: String) = name + val newRHS = super.transform(rhs) + val named = q"chisel3.experimental.autoNameRecursively($str, $newRHS)" + treeCopy.ValDef(dd, mods, name, tpt, localTyper typed named) + // If a Data or a Memory, get the name and a prefix + case dd @ ValDef(mods, name, tpt, rhs) if okVal(dd, tq"chisel3.Data", tq"chisel3.MemBase[_]") => + val TermName(str: String) = name + val newRHS = super.transform(rhs) + val prefixed = q"chisel3.experimental.prefix.apply[$tpt](name=$str)(f=$newRHS)" + val named = q"chisel3.experimental.autoNameRecursively($str, $prefixed)" + treeCopy.ValDef(dd, mods, name, tpt, localTyper typed named) + // If an instance, just get a name but no prefix + case dd @ ValDef(mods, name, tpt, rhs) if okVal(dd, tq"chisel3.experimental.BaseModule") => + val TermName(str: String) = name + val newRHS = super.transform(rhs) + val named = q"chisel3.experimental.autoNameRecursively($str, $newRHS)" + treeCopy.ValDef(dd, mods, name, tpt, localTyper typed named) + // Otherwise, continue + case _ => super.transform(tree) + } + } +} -- cgit v1.2.3