refactor: return args and defs from labelGenerator, instead of strings

src/main/wacc/backend/LabelGenerator.scala

@@ -17,23 +17,27 @@ private class LabelGenerator {
     s".L$labelVal"
   }
 
-  /** Get a named label for a function. */
-  def getLabel(target: CallTarget): String = target match {
-    case Ident(v, _)   => s"wacc_$v"
-    case Builtin(name) => s"_$name"
+  private def getLabel(target: CallTarget | RuntimeError): String = target match {
+    case Ident(v, _)       => s"wacc_$v"
+    case Builtin(name)     => s"_$name"
+    case err: RuntimeError => s".L.${err.name}"
   }
 
-  /** Get a named label for an error. */
-  def getLabel(target: RuntimeError): String =
-    s".L.${target.name}"
+  /** Get a named label def for a function or error. */
+  def getLabelDef(target: CallTarget | RuntimeError): LabelDef =
+    LabelDef(getLabel(target))
+
+  /** Get a named label for a function or error. */
+  def getLabelArg(target: CallTarget | RuntimeError): LabelArg =
+    LabelArg(getLabel(target))
 
   /** Get an arbitrary label for a string. */
-  def getLabel(str: String): String =
-    strings.getOrElseUpdate(str, s".L.str${strings.size}")
+  def getLabelArg(str: String): LabelArg =
+    LabelArg(strings.getOrElseUpdate(str, s".L.str${strings.size}"))
 
   /** Get a named label for a string. */
-  def getLabel(src: String, name: String): String =
-    strings.getOrElseUpdate(src, s".L.$name.str${strings.size}")
+  def getLabelArg(src: String, name: String): LabelArg =
+    LabelArg(strings.getOrElseUpdate(src, s".L.$name.str${strings.size}"))
 
   /** Generate the assembly labels for constants that were labelled using the LabelGenerator. */
   def generateConstants: Chain[AsmLine] =