feat: implement .loc, .file and .func debug directives

src/main/wacc/backend/LabelGenerator.scala

@@ -2,6 +2,7 @@ package wacc
 
 import scala.collection.mutable
 import cats.data.Chain
+import wacc.ast.Position
 
 private class LabelGenerator {
   import assemblyIR._
@@ -9,7 +10,9 @@ private class LabelGenerator {
   import asmGenerator.escaped
 
   private val strings = mutable.HashMap[String, String]()
+  private val files = mutable.HashMap[String, Int]()
   private var labelVal = -1
+  private var permittedFuncFile: Option[String] = None
 
   /** Get an arbitrary label. */
   def getLabel(): String = {
@@ -39,6 +42,25 @@ private class LabelGenerator {
   def getLabelArg(src: String, name: String): LabelArg =
     LabelArg(strings.getOrElseUpdate(src, s".L.$name.str${strings.size}"))
 
+  /** Get a debug directive for a file. */
+  def getDebugFile(file: java.io.File): Int =
+    files.getOrElseUpdate(file.getCanonicalPath, files.size)
+
+  /** Get a debug directive for a function. */
+  def getDebugFunc(pos: Position, name: String, label: LabelDef): Chain[AsmLine] = {
+    permittedFuncFile match {
+      case Some(f) if f != pos.file.getCanonicalPath => Chain.empty
+      case _ =>
+        permittedFuncFile = Some(pos.file.getCanonicalPath)
+        Chain(
+          LabelDef(name),
+          Directive.Location(getDebugFile(pos.file), pos.line, None),
+          Directive.Type(label, SymbolType.Function),
+          Directive.Func(name, label)
+        )
+    }
+  }
+
   /** Generate the assembly labels for constants that were labelled using the LabelGenerator. */
   def generateConstants: Chain[AsmLine] =
     strings.foldLeft(Chain.empty) { case (acc, (str, label)) =>
@@ -47,4 +69,10 @@ private class LabelGenerator {
         Directive.Asciz(str.escaped)
       )
     }
+
+  /** Generates debug directives that were created using the LabelGenerator. */
+  def generateDebug: Chain[AsmLine] =
+    files.foldLeft(Chain.empty) { case (acc, (file, no)) =>
+      acc :+ Directive.File(no, file)
+    }
 }