tilelink2: get rid of fragile implicit lazyModule pattern, and support :=

We can more reliably find the current LazyModule from the LazyModule.stack

src/main/scala/uncore/tilelink2/Buffer.scala

@@ -39,10 +39,10 @@ class TLBuffer(entries: Int = 2, pipe: Boolean = false) extends LazyModule
 
 object TLBuffer
 {
-  // applied to the TL source node; connect (TLBuffer(x.node) -> y.node)
+  // applied to the TL source node; y.node := TLBuffer(x.node)
-  def apply(x: TLBaseNode, entries: Int = 2, pipe: Boolean = false)(implicit lazyModule: LazyModule, sourceInfo: SourceInfo): TLBaseNode = {
+  def apply(x: TLBaseNode, entries: Int = 2, pipe: Boolean = false)(implicit sourceInfo: SourceInfo): TLBaseNode = {
     val buffer = LazyModule(new TLBuffer(entries, pipe))
-    lazyModule.connect(x -> buffer.node)
+    buffer.node := x
     buffer.node
   }
 }

src/main/scala/uncore/tilelink2/Fragmenter.scala

@@ -240,10 +240,10 @@ class TLFragmenter(minSize: Int, maxSize: Int, alwaysMin: Boolean = false) exten
 
 object TLFragmenter
 {
-  // applied to the TL source node; connect (TLFragmenter(x.node, 256, 4) -> y.node)
+  // applied to the TL source node; y.node := TLFragmenter(x.node, 256, 4)
-  def apply(x: TLBaseNode, minSize: Int, maxSize: Int, alwaysMin: Boolean = false)(implicit lazyModule: LazyModule, sourceInfo: SourceInfo): TLBaseNode = {
+  def apply(x: TLBaseNode, minSize: Int, maxSize: Int, alwaysMin: Boolean = false)(implicit sourceInfo: SourceInfo): TLBaseNode = {
     val fragmenter = LazyModule(new TLFragmenter(minSize, maxSize, alwaysMin))
-    lazyModule.connect(x -> fragmenter.node)
+    fragmenter.node := x
     fragmenter.node
   }
 }

src/main/scala/uncore/tilelink2/HintHandler.scala

@@ -90,10 +90,10 @@ class TLHintHandler(supportManagers: Boolean = true, supportClients: Boolean = f
 
 object TLHintHandler
 {
-  // applied to the TL source node; connect (TLHintHandler(x.node) -> y.node)
+  // applied to the TL source node; y.node := TLHintHandler(x.node)
-  def apply(x: TLBaseNode, supportManagers: Boolean = true, supportClients: Boolean = false, passthrough: Boolean = true)(implicit lazyModule: LazyModule, sourceInfo: SourceInfo): TLBaseNode = {
+  def apply(x: TLBaseNode, supportManagers: Boolean = true, supportClients: Boolean = false, passthrough: Boolean = true)(implicit sourceInfo: SourceInfo): TLBaseNode = {
     val hints = LazyModule(new TLHintHandler(supportManagers, supportClients, passthrough))
-    lazyModule.connect(x -> hints.node)
+    hints.node := x
     hints.node
   }
 }

src/main/scala/uncore/tilelink2/LazyModule.scala

@@ -18,16 +18,13 @@ abstract class LazyModule
 
   // Use as: connect(source -> sink, source2 -> sink2, ...)
   def connect[PO, PI, EO, EI, B <: Data](edges: (BaseNode[PO, PI, EO, EI, B], BaseNode[PO, PI, EO, EI, B])*)(implicit sourceInfo: SourceInfo) = {
-    edges.foreach { case (source, sink) =>
+    edges.foreach { case (source, sink) => sink := source }
-      bindings = (source edge sink) :: bindings
-    }
   }
 
   def name = getClass.getName.split('.').last
   def line = sourceLine(info)
 
   def module: LazyModuleImp
-  implicit val lazyModule = this
 
   protected[tilelink2] def instantiate() = {
     children.reverse.foreach { c => 

src/main/scala/uncore/tilelink2/Nodes.scala

@@ -76,20 +76,21 @@ class BaseNode[PO, PI, EO, EI, B <: Data](imp: NodeImp[PO, PI, EO, EI, B])(
   def connectOut = bundleOut
   def connectIn = bundleIn
 
-  // source.edge(sink)
+  protected[tilelink2] def := (y: BaseNode[PO, PI, EO, EI, B])(implicit sourceInfo: SourceInfo) = {
-  protected[tilelink2] def edge(x: BaseNode[PO, PI, EO, EI, B])(implicit sourceInfo: SourceInfo) = {
+    val x = this // x := y
     val info = sourceLine(sourceInfo, " at ", "")
-    require (!noOs, s"${name}${lazyModule.line} was incorrectly connected as a source" + info)
+    require (!LazyModule.stack.isEmpty, s"${y.name} cannot be connected to ${x.name} outside of LazyModule scope" + info)
-    require (!oRealized, s"${name}${lazyModule.line} was incorrectly connected as a source after it's .module was used" + info)
+    require (!y.noOs, s"${y.name}${y.lazyModule.line} was incorrectly connected as a source" + info)
+    require (!y.oRealized, s"${y.name}${y.lazyModule.line} was incorrectly connected as a source after it's .module was used" + info)
     require (!x.noIs, s"${x.name}${x.lazyModule.line} was incorrectly connected as a sink" + info)
     require (!x.iRealized, s"${x.name}${x.lazyModule.line} was incorrectly connected as a sink after it's .module was used" + info)
     val i = x.accPI.size
-    val o = accPO.size
+    val o = y.accPO.size
-    accPO += ((i, x))
+    y.accPO += ((i, x))
-    x.accPI += ((o, this))
+    x.accPI += ((o, y))
-    () => {
+    LazyModule.stack.head.bindings = (() => {
-      imp.connect(connectOut(o), edgesOut(o), x.connectIn(i), x.edgesIn(i))
+      imp.connect(y.connectOut(o), y.edgesOut(o), x.connectIn(i), x.edgesIn(i))
-    }
+    }) :: LazyModule.stack.head.bindings
   }
 }
 

src/main/scala/uncore/tilelink2/WidthWidget.scala

@@ -171,10 +171,10 @@ class TLWidthWidget(innerBeatBytes: Int) extends LazyModule
 
 object TLWidthWidget
 {
-  // applied to the TL source node; connect (WidthWidget(x.node, 16) -> y.node)
+  // applied to the TL source node; y.node := WidthWidget(x.node, 16)
-  def apply(x: TLBaseNode, innerBeatBytes: Int)(implicit lazyModule: LazyModule, sourceInfo: SourceInfo): TLBaseNode = {
+  def apply(x: TLBaseNode, innerBeatBytes: Int)(implicit sourceInfo: SourceInfo): TLBaseNode = {
     val widget = LazyModule(new TLWidthWidget(innerBeatBytes))
-    lazyModule.connect(x -> widget.node)
+    widget.node := x
     widget.node
   }
 }