1 files changed, 190 insertions, 0 deletions
diff --git a/chiselFrontend/src/main/scala/chisel3/internal/Builder.scala b/chiselFrontend/src/main/scala/chisel3/internal/Builder.scala
new file mode 100644
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--- /dev/null
+++ b/chiselFrontend/src/main/scala/chisel3/internal/Builder.scala
@@ -0,0 +1,190 @@
+// See LICENSE for license details.
+
+package chisel3.internal
+
+import scala.util.DynamicVariable
+import scala.collection.mutable.{ArrayBuffer, HashMap}
+
+import chisel3._
+import core._
+import firrtl._
+
+private[chisel3] class Namespace(parent: Option[Namespace], keywords: Set[String]) {
+  private val names = collection.mutable.HashMap[String, Long]()
+  for (keyword <- keywords)
+    names(keyword) = 1
+
+  private def rename(n: String): String = {
+    val index = names.getOrElse(n, 1L)
+    val tryName = s"${n}_${index}"
+    names(n) = index + 1
+    if (this contains tryName) rename(n) else tryName
+  }
+
+  private def sanitize(s: String): String = {
+    // TODO what character set does FIRRTL truly support? using ANSI C for now
+    def legalStart(c: Char) = (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || c == '_'
+    def legal(c: Char) = legalStart(c) || (c >= '0' && c <= '9')
+    val res = s filter legal
+    if (res.isEmpty || !legalStart(res.head)) s"_$res" else res
+  }
+
+  def contains(elem: String): Boolean = {
+    names.contains(elem) || parent.map(_ contains elem).getOrElse(false)
+  }
+
+  def name(elem: String): String = {
+    val sanitized = sanitize(elem)
+    if (this contains sanitized) {
+      name(rename(sanitized))
+    } else {
+      names(sanitized) = 1
+      sanitized
+    }
+  }
+
+  def child(kws: Set[String]): Namespace = new Namespace(Some(this), kws)
+  def child: Namespace = child(Set())
+}
+
+private[chisel3] class IdGen {
+  private var counter = -1L
+  def next: Long = {
+    counter += 1
+    counter
+  }
+}
+
+/** Public API to access Node/Signal names.
+  * currently, the node's name, the full path name, and references to its parent Module and component.
+  * These are only valid once the design has been elaborated, and should not be used during its construction.
+  */
+trait InstanceId {
+  def instanceName: String
+  def pathName: String
+  def parentPathName: String
+  def parentModName: String
+}
+
+private[chisel3] trait HasId extends InstanceId {
+  private[chisel3] def _onModuleClose: Unit = {} // scalastyle:ignore method.name
+  private[chisel3] val _parent: Option[Module] = Builder.currentModule
+  _parent.foreach(_.addId(this))
+
+  private[chisel3] val _id: Long = 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[chisel3] 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[chisel3] 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[chisel3] def setRef(imm: Arg): Unit = _ref = Some(imm)
+  private[chisel3] def setRef(parent: HasId, name: String): Unit = setRef(Slot(Node(parent), name))
+  private[chisel3] def setRef(parent: HasId, index: Int): Unit = setRef(Index(Node(parent), ILit(index)))
+  private[chisel3] def setRef(parent: HasId, index: UInt): Unit = setRef(Index(Node(parent), index.ref))
+  private[chisel3] def getRef: Arg = _ref.get
+
+  // Implementation of public methods.
+  def instanceName = _parent match {
+    case Some(p) => p._component match {
+      case Some(c) => getRef fullName c
+      case None => throwException("signalName/pathName should be called after circuit elaboration")
+    }
+    case None => throwException("this cannot happen")
+  }
+  def pathName = _parent match {
+    case None => instanceName
+    case Some(p) => s"${p.pathName}.$instanceName"
+  }
+  def parentPathName = _parent match {
+    case Some(p) => p.pathName
+    case None => throwException(s"$instanceName doesn't have a parent")
+  }
+  def parentModName = _parent match {
+    case Some(p) => p.modName
+    case None => throwException(s"$instanceName doesn't have a parent")
+  }
+}
+
+private[chisel3] 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[chisel3] object Builder {
+  // All global mutable state must be referenced via dynamicContextVar!!
+  private val dynamicContextVar = new DynamicVariable[Option[DynamicContext]](None)
+  private def dynamicContext: DynamicContext =
+    dynamicContextVar.value.getOrElse(new DynamicContext)
+
+  def idGen: IdGen = dynamicContext.idGen
+  def globalNamespace: Namespace = dynamicContext.globalNamespace
+  def components: ArrayBuffer[Component] = dynamicContext.components
+
+  def currentModule: Option[Module] = dynamicContext.currentModule
+  def currentModule_=(target: Option[Module]): Unit = {
+    dynamicContext.currentModule = target
+  }
+  def forcedModule: Module = currentModule match {
+    case Some(module) => module
+    case None => throw new Exception(
+      "Error: Not in a Module. Likely cause: Missed Module() wrap or bare chisel API call."
+      // A bare api call is, e.g. calling Wire() from the scala console).
+    )
+  }
+
+  // TODO(twigg): Ideally, binding checks and new bindings would all occur here
+  // However, rest of frontend can't support this yet.
+  def pushCommand[T <: Command](c: T): T = {
+    forcedModule._commands += c
+    c
+  }
+  def pushOp[T <: Data](cmd: DefPrim[T]): T = {
+    // Bind each element of the returned Data to being a Op
+    Binding.bind(cmd.id, OpBinder(forcedModule), "Error: During op creation, fresh result")
+    pushCommand(cmd).id
+  }
+
+  def errors: ErrorLog = dynamicContext.errors
+  def error(m: => String): Unit = errors.error(m)
+  def warning(m: => String): Unit = errors.warning(m)
+  def deprecated(m: => String): Unit = errors.deprecated(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)
+    }
+  }
+}