1 files changed, 122 insertions, 0 deletions
diff --git a/chiselFrontend/src/main/scala/Chisel/internal/Builder.scala b/chiselFrontend/src/main/scala/Chisel/internal/Builder.scala
new file mode 100644
index 00000000..c7ecdaa0
--- /dev/null
+++ b/chiselFrontend/src/main/scala/Chisel/internal/Builder.scala
@@ -0,0 +1,122 @@
+// See LICENSE for license details.
+
+package Chisel.internal
+
+import scala.util.DynamicVariable
+import scala.collection.mutable.{ArrayBuffer, HashMap}
+
+import Chisel._
+import Chisel.internal.firrtl._
+
+private[Chisel] class Namespace(parent: Option[Namespace], keywords: Set[String]) {
+  private var i = 0L
+  private val names = collection.mutable.HashSet[String]()
+
+  private def rename(n: String) = { i += 1; s"${n}_${i}" }
+
+  def contains(elem: String): Boolean = {
+    keywords.contains(elem) || names.contains(elem) ||
+      parent.map(_ contains elem).getOrElse(false)
+  }
+
+  def name(elem: String): String = {
+    if (this contains elem) {
+      name(rename(elem))
+    } else {
+      names += elem
+      elem
+    }
+  }
+
+  def child(kws: Set[String]): Namespace = new Namespace(Some(this), kws)
+  def child: Namespace = child(Set())
+}
+
+private[Chisel] class IdGen {
+  private var counter = -1L
+  def next: Long = {
+    counter += 1
+    counter
+  }
+}
+
+private[Chisel] trait HasId {
+  private[Chisel] def _onModuleClose {} // scalastyle:ignore method.name
+  private[Chisel] val _parent = Builder.dynamicContext.currentModule
+  _parent.foreach(_.addId(this))
+
+  private[Chisel] val _id = Builder.idGen.next
+  override def hashCode: Int = _id.toInt
+  override def equals(that: Any): Boolean = that match {
+    case x: HasId => _id == x._id
+    case _ => false
+  }
+
+  // Facilities for 'suggesting' a name to this.
+  // Post-name hooks called to carry the suggestion to other candidates as needed
+  private var suggested_name: Option[String] = None
+  private val postname_hooks = scala.collection.mutable.ListBuffer.empty[String=>Unit]
+  // Only takes the first suggestion!
+  def suggestName(name: =>String): this.type = {
+    if(suggested_name.isEmpty) suggested_name = Some(name)
+    for(hook <- postname_hooks) { hook(name) }
+    this
+  }
+  private[Chisel] def addPostnameHook(hook: String=>Unit): Unit = postname_hooks += hook
+
+  // Uses a namespace to convert suggestion into a true name
+  // Will not do any naming if the reference already assigned.
+  // (e.g. tried to suggest a name to part of a Bundle)
+  private[Chisel] def forceName(default: =>String, namespace: Namespace): Unit =
+    if(_ref.isEmpty) {
+      val candidate_name = suggested_name.getOrElse(default)
+      val available_name = namespace.name(candidate_name)
+      setRef(Ref(available_name))
+    }
+
+  private var _ref: Option[Arg] = None
+  private[Chisel] def setRef(imm: Arg): Unit = _ref = Some(imm)
+  private[Chisel] def setRef(parent: HasId, name: String): Unit = setRef(Slot(Node(parent), name))
+  private[Chisel] def setRef(parent: HasId, index: Int): Unit = setRef(Index(Node(parent), ILit(index)))
+  private[Chisel] def setRef(parent: HasId, index: UInt): Unit = setRef(Index(Node(parent), index.ref))
+  private[Chisel] def getRef: Arg = _ref.get
+}
+
+private[Chisel] class DynamicContext {
+  val idGen = new IdGen
+  val globalNamespace = new Namespace(None, Set())
+  val components = ArrayBuffer[Component]()
+  var currentModule: Option[Module] = None
+  val errors = new ErrorLog
+}
+
+private[Chisel] object Builder {
+  // All global mutable state must be referenced via dynamicContextVar!!
+  private val dynamicContextVar = new DynamicVariable[Option[DynamicContext]](None)
+
+  def dynamicContext: DynamicContext = dynamicContextVar.value.get
+  def idGen: IdGen = dynamicContext.idGen
+  def globalNamespace: Namespace = dynamicContext.globalNamespace
+  def components: ArrayBuffer[Component] = dynamicContext.components
+
+  def pushCommand[T <: Command](c: T): T = {
+    dynamicContext.currentModule.foreach(_._commands += c)
+    c
+  }
+  def pushOp[T <: Data](cmd: DefPrim[T]): T = pushCommand(cmd).id
+
+  def errors: ErrorLog = dynamicContext.errors
+  def error(m: => String): Unit = errors.error(m)
+
+  def build[T <: Module](f: => T): Circuit = {
+    dynamicContextVar.withValue(Some(new DynamicContext)) {
+      errors.info("Elaborating design...")
+      val mod = f
+      mod.forceName(mod.name, globalNamespace)
+      errors.checkpoint()
+      errors.info("Done elaborating.")
+
+      Circuit(components.last.name, components)
+    }
+  }
+}