Remove state from TreeMapWithStages

nicolasstucki · nicolasstucki · commit 095a7f1e53b8 · 2023-05-01T11:00:07.000+02:00
diff --git a/compiler/src/dotty/tools/dotc/staging/CrossStageSafety.scala b/compiler/src/dotty/tools/dotc/staging/CrossStageSafety.scala
@@ -50,7 +50,7 @@ class CrossStageSafety extends TreeMapWithStages {
   override def transform(tree: Tree)(using Context): Tree =
     if (tree.source != ctx.source && tree.source.exists)
       transform(tree)(using ctx.withSource(tree.source))
-    else if !isInQuoteOrSplice then
+    else if !inQuoteOrSpliceScope then
       checkAnnotations(tree)
       super.transform(tree)
     else tree match {
diff --git a/compiler/src/dotty/tools/dotc/staging/StagingLevel.scala b/compiler/src/dotty/tools/dotc/staging/StagingLevel.scala
@@ -31,6 +31,10 @@ object StagingLevel {
   def spliceContext(using Context): FreshContext =
     ctx.fresh.setProperty(LevelKey, level - 1)
 
+  /** If we are inside a quote or a splice */
+  def inQuoteOrSpliceScope(using Context): Boolean =
+    ctx.property(LevelKey).isDefined
+
   /** The quotation level of the definition of the locally defined symbol */
   def levelOf(sym: Symbol)(using Context): Int =
     ctx.property(LevelOfKey) match
diff --git a/compiler/src/dotty/tools/dotc/staging/TreeMapWithStages.scala b/compiler/src/dotty/tools/dotc/staging/TreeMapWithStages.scala
@@ -15,12 +15,6 @@ import scala.collection.mutable
 abstract class TreeMapWithStages extends TreeMapWithImplicits {
   import tpd._
 
-  /** If we are inside a quote or a splice */
-  private[this] var inQuoteOrSplice = false
-
-  /** If we are inside a quote or a splice */
-  protected def isInQuoteOrSplice: Boolean = inQuoteOrSplice
-
   /** Transform the quote `quote` which contains the quoted `body`.
    *
    *  - `quoted.runtime.Expr.quote[T](<body0>)`  --> `quoted.runtime.Expr.quote[T](<body>)`
@@ -53,41 +47,28 @@ abstract class TreeMapWithStages extends TreeMapWithImplicits {
 
       tree match {
         case tree @ QuotedTypeOf(quotedTree) =>
-          val old = inQuoteOrSplice
-          inQuoteOrSplice = true
-          try transformQuotedType(quotedTree, tree)
-          finally inQuoteOrSplice = old
-
+          transformQuotedType(quotedTree, tree)
         case tree @ Quote(quotedTree) =>
-          val old = inQuoteOrSplice
-          inQuoteOrSplice = true
-          try dropEmptyBlocks(quotedTree) match {
+          dropEmptyBlocks(quotedTree) match {
             case Splice(t) =>
               // Optimization: `'{ $x }` --> `x`
               // and adapt the refinement of `Quotes { type reflect: ... } ?=> Expr[T]`
               transform(t).asInstance(tree.tpe)
             case _ =>
               transformQuote(quotedTree, tree)
           }
-          finally inQuoteOrSplice = old
 
         case tree @ Splice(splicedTree) =>
-          val old = inQuoteOrSplice
-          inQuoteOrSplice = true
-          try dropEmptyBlocks(splicedTree) match {
+          dropEmptyBlocks(splicedTree) match {
             case Quote(t) =>
               // Optimization: `${ 'x }` --> `x`
               transform(t)
             case _ =>
               transformSplice(splicedTree, tree)
           }
-          finally inQuoteOrSplice = old
 
         case tree @ SplicedType(splicedTree) =>
-          val old = inQuoteOrSplice
-          inQuoteOrSplice = true
-          try transformSpliceType(splicedTree, tree)
-          finally inQuoteOrSplice = old
+          transformSpliceType(splicedTree, tree)
 
         case Block(stats, _) =>
           val defSyms = stats.collect { case defTree: DefTree => defTree.symbol }
