Cache ctx.settings.Yscala2Stdlib.value

Author: nicolasstucki

compiler/src/dotty/tools/dotc/ast/Desugar.scala

@@ -19,6 +19,7 @@ import printing.Formatting.hl
 import config.Printers
 
 import scala.annotation.internal.sharable
+import scala.annotation.threadUnsafe
 
 object desugar {
   import untpd._
@@ -487,6 +488,7 @@ object desugar {
     def isNonEnumCase = !isEnumCase && (isCaseClass || isCaseObject)
     val isValueClass = parents.nonEmpty && isAnyVal(parents.head)
       // This is not watertight, but `extends AnyVal` will be replaced by `inline` later.
+    val caseClassInScala2StdLib = isCaseClass && ctx.settings.Yscala2Stdlib.value
 
     val originalTparams = constr1.leadingTypeParams
     val originalVparamss = asTermOnly(constr1.trailingParamss)
@@ -662,9 +664,7 @@ object desugar {
     //       new C[...](p1, ..., pN)(moreParams)
     val (caseClassMeths, enumScaffolding) = {
       def syntheticProperty(name: TermName, tpt: Tree, rhs: Tree) =
-        val mods =
-          if ctx.settings.Yscala2Stdlib.value then synthetic | Inline
-          else synthetic
+        val mods = if caseClassInScala2StdLib then synthetic | Inline else synthetic
         DefDef(name, Nil, tpt, rhs).withMods(mods)
 
       def productElemMeths =
@@ -782,7 +782,7 @@ object desugar {
           val unapplyParam = makeSyntheticParameter(tpt = classTypeRef)
           val unapplyRHS =
             if (arity == 0) Literal(Constant(true))
-            else if ctx.settings.Yscala2Stdlib.value then scala2LibCompatUnapplyRhs(unapplyParam.name)
+            else if caseClassInScala2StdLib then scala2LibCompatUnapplyRhs(unapplyParam.name)
             else Ident(unapplyParam.name)
           val unapplyResTp = if (arity == 0) Literal(Constant(true)) else TypeTree()
 

compiler/src/dotty/tools/dotc/transform/PostTyper.scala

@@ -80,6 +80,10 @@ class PostTyper extends MacroTransform with InfoTransformer { thisPhase =>
   def newTransformer(using Context): Transformer =
     new PostTyperTransformer
 
+  private var compilingScala2StdLib = false
+  override def initContext(ctx: FreshContext): Unit =
+    compilingScala2StdLib = ctx.settings.Yscala2Stdlib.value(using ctx)
+
   val superAcc: SuperAccessors = new SuperAccessors(thisPhase)
   val synthMbr: SyntheticMembers = new SyntheticMembers(thisPhase)
   val beanProps: BeanProperties = new BeanProperties(thisPhase)
@@ -536,7 +540,7 @@ class PostTyper extends MacroTransform with InfoTransformer { thisPhase =>
 
     private def scala2LibPatch(tree: TypeDef)(using Context) =
       val sym = tree.symbol
-      if ctx.settings.Yscala2Stdlib.value
+      if compilingScala2StdLib
         && sym.is(ModuleClass) && !sym.derivesFrom(defn.SerializableClass)
         && sym.companionClass.derivesFrom(defn.SerializableClass)
       then
@@ -550,7 +554,7 @@ class PostTyper extends MacroTransform with InfoTransformer { thisPhase =>
   }
 
   protected override def infoMayChange(sym: Symbol)(using Context): Boolean =
-    ctx.settings.Yscala2Stdlib.value && sym.isAllOf(ModuleClass, butNot = Package)
+    compilingScala2StdLib && sym.isAllOf(ModuleClass, butNot = Package)
 
   def transformInfo(tp: Type, sym: Symbol)(using Context): Type = tp match
     case info: ClassInfo =>