Allow Side Effecting Statement to have Names (#2057)

* firrtl: add optional statement labels for stop, printf, assert, assume and cover

* test: parsing of statement labels

* ir: ensure that name is properly retained

* SymbolTable: add support for labled statements

* test: parsing statement labels

* test: lower types name collisions with named statements

* ignore empty names

* Inline: deal with named and unnamed statements

* RemoveWires: treat stop, printf and verification statements as "others"

* test: fix InlineInstance tests

* DeadCodeEliminations: statements are now als declarations

* CheckHighForm: ensure that statement names are not used as references

* CheckSpec: throw error if statement name collides

* add pass to automatically add missing statement names

* check: make sure that two statements cannot have the same name

* stmtLabel -> stmtName

* scalafmt

* add statement names to spec

* spec: meta data -> metadata

* EnsureStatementNames: explain naming algorithm

* remove returns

* better namespace use

* ir: add CanBeReferenced trait

* ir: add newline as jack requested

1 files changed, 12 insertions, 6 deletions

diff --git a/src/main/scala/firrtl/ir/Serializer.scala b/src/main/scala/firrtl/ir/Serializer.scala
index 983a7866..caea0a9c 100644
--- a/src/main/scala/firrtl/ir/Serializer.scala
+++ b/src/main/scala/firrtl/ir/Serializer.scala
@@ -102,11 +102,13 @@ object Serializer {
         s(it.next())
         if (it.hasNext) newLineAndIndent()
       }
-    case Stop(info, ret, clk, en) =>
-      b ++= "stop("; s(clk); b ++= ", "; s(en); b ++= ", "; b ++= ret.toString; b += ')'; s(info)
-    case Print(info, string, args, clk, en) =>
+    case stop @ Stop(info, ret, clk, en) =>
+      b ++= "stop("; s(clk); b ++= ", "; s(en); b ++= ", "; b ++= ret.toString; b += ')'
+      sStmtName(stop.name); s(info)
+    case print @ Print(info, string, args, clk, en) =>
       b ++= "printf("; s(clk); b ++= ", "; s(en); b ++= ", "; b ++= string.escape
-      if (args.nonEmpty) b ++= ", "; s(args, ", "); b += ')'; s(info)
+      if (args.nonEmpty) b ++= ", "; s(args, ", "); b += ')'
+      sStmtName(print.name); s(info)
     case IsInvalid(info, expr)    => s(expr); b ++= " is invalid"; s(info)
     case DefWire(info, name, tpe) => b ++= "wire "; b ++= name; b ++= " : "; s(tpe); s(info)
     case DefRegister(info, name, tpe, clock, reset, init) =>
@@ -138,9 +140,9 @@ object Serializer {
     case Attach(info, exprs)             =>
       // exprs should never be empty since the attach statement takes *at least* two signals according to the spec
       b ++= "attach ("; s(exprs, ", "); b += ')'; s(info)
-    case Verification(op, info, clk, pred, en, msg) =>
+    case veri @ Verification(op, info, clk, pred, en, msg) =>
       b ++= op.toString; b += '('; s(List(clk, pred, en), ", ", false); b ++= msg.escape
-      b += ')'; s(info)
+      b += ')'; sStmtName(veri.name); s(info)
 
     // WIR
     case firrtl.CDefMemory(info, name, tpe, size, seq, readUnderWrite) =>
@@ -155,6 +157,10 @@ object Serializer {
     case other => b ++= other.serialize // Handle user-defined nodes
   }
 
+  private def sStmtName(lbl: String)(implicit b: StringBuilder): Unit = {
+    if (lbl.nonEmpty) { b ++= s" : $lbl" }
+  }
+
   private def s(node: Width)(implicit b: StringBuilder, indent: Int): Unit = node match {
     case IntWidth(width) => b += '<'; b ++= width.toString(); b += '>'
     case UnknownWidth    => // empty string