Avoid leak of internal implementation in tasty.Reflection

* Remove `Reflection.internal`: the source of the leak
* Add `CompilerInterface` as a self type
* Add common type abstraction for `Reflection` and `ComplerInterface`
* Add `ComplerInterface.leak` to allow access to internals within the library

Author: nicolasstucki

compiler/src/dotty/tools/dotc/tastyreflect/ReflectionCompilerInterface.scala

@@ -21,7 +21,11 @@ import scala.internal.tasty.CompilerInterface
 
 import scala.tasty.reflect.TypeTest
 
-class ReflectionCompilerInterface(val rootContext: core.Contexts.Context) extends CompilerInterface {
+// NOTE: `ReflectionCompilerInterface` should be a class to make sure that all functionality of
+//       `CompilerInterface` is implemented here.
+
+/** Part of the reflection interface that is implemented by the compiler */
+class ReflectionCompilerInterface(val rootContext: Context) extends CompilerInterface {
   import tpd._
 
   private given core.Contexts.Context = rootContext

compiler/src/dotty/tools/dotc/tastyreflect/ReflectionImpl.scala

@@ -9,10 +9,10 @@ import scala.quoted.show.SyntaxHighlight
 object ReflectionImpl {
 
   def apply(rootContext: Contexts.Context): scala.tasty.Reflection =
-    new scala.tasty.Reflection(new ReflectionCompilerInterface(rootContext))
+    new ReflectionImpl(rootContext)
 
   def showTree(tree: tpd.Tree)(using Contexts.Context): String = {
-    val refl = new scala.tasty.Reflection(new ReflectionCompilerInterface(MacroExpansion.context(tree)))
+    val refl = new ReflectionImpl(MacroExpansion.context(tree))
     val reflCtx = ctx.asInstanceOf[refl.Context]
     val reflTree = tree.asInstanceOf[refl.Tree]
     val syntaxHighlight =
@@ -22,3 +22,6 @@ object ReflectionImpl {
   }
 }
 
+// NOTE: This class should only mixin the compiler interface and the reflection interface.
+//       We should not implementt methods here, all should be implemented by `ReflectionCompilerInterface`
+class ReflectionImpl(ctx: Context) extends ReflectionCompilerInterface(ctx) with scala.tasty.Reflection

library/src-bootstrapped/scala/internal/quoted/Expr.scala

@@ -19,7 +19,7 @@ import scala.quoted._
   }
 
   def unseal(using qctx: QuoteContext): qctx.tasty.Term =
-    if (qctx.tasty.internal.compilerId != scopeId)
+    if (scala.internal.tasty.CompilerInterface.leaked(qctx).tasty.compilerId != scopeId)
       throw new scala.quoted.ScopeException("Cannot call `scala.quoted.staging.run(...)` within a macro or another `run(...)`")
     tree.asInstanceOf[qctx.tasty.Term]
 
@@ -52,7 +52,7 @@ object Expr {
    */
   def unapply[TypeBindings <: Tuple, Tup <: Tuple](scrutineeExpr: scala.quoted.Expr[Any])(using patternExpr: scala.quoted.Expr[Any],
         hasTypeSplices: Boolean, qctx: QuoteContext): Option[Tup] = {
-    new Matcher.QuoteMatcher[qctx.type].termMatch(scrutineeExpr.unseal, patternExpr.unseal, hasTypeSplices).asInstanceOf[Option[Tup]]
+    new Matcher.QuoteMatcher[qctx.type](qctx).termMatch(scrutineeExpr.unseal, patternExpr.unseal, hasTypeSplices).asInstanceOf[Option[Tup]]
   }
 
   /** Returns a null expresssion equivalent to `'{null}` */

library/src-bootstrapped/scala/internal/quoted/Matcher.scala

@@ -122,7 +122,9 @@ object Matcher {
   @compileTimeOnly("Illegal reference to `scala.internal.quoted.CompileTime.fromAbove`")
   class fromAbove extends Annotation
 
-  class QuoteMatcher[QCtx <: QuoteContext & Singleton](using val qctx: QCtx) {
+  class QuoteMatcher[QCtx <: QuoteContext & Singleton](val qctx0: QCtx) {
+    val qctx = scala.internal.tasty.CompilerInterface.leaked(qctx0)
+
     // TODO improve performance
 
     // TODO use flag from qctx.tasty.rootContext. Maybe -debug or add -debug-macros
@@ -147,14 +149,14 @@ object Matcher {
     def termMatch(scrutineeTerm: Term, patternTerm: Term, hasTypeSplices: Boolean): Option[Tuple] = {
       given Env = Map.empty
       if (hasTypeSplices) {
-        val ctx: Context = internal.Constraints_init(rootContext)
+        val ctx: Context = qctx.tasty.Constraints_init(rootContext)
         given Context = ctx
         val matchings = scrutineeTerm =?= patternTerm
         // After matching and doing all subtype checks, we have to approximate all the type bindings
         // that we have found and seal them in a quoted.Type
         matchings.asOptionOfTuple.map { tup =>
           Tuple.fromArray(tup.toArray.map { // TODO improve performance
-            case x: SymBinding => internal.Constraints_approximation(summon[Context])(x.sym, !x.fromAbove).seal
+            case x: SymBinding => qctx.tasty.Constraints_approximation(summon[Context])(x.sym, !x.fromAbove).seal
             case x => x
           })
         }
@@ -168,14 +170,14 @@ object Matcher {
     def typeTreeMatch(scrutineeTypeTree: TypeTree, patternTypeTree: TypeTree, hasTypeSplices: Boolean): Option[Tuple] = {
       given Env = Map.empty
       if (hasTypeSplices) {
-        val ctx: Context = internal.Constraints_init(rootContext)
+        val ctx: Context = qctx.tasty.Constraints_init(rootContext)
         given Context = ctx
         val matchings = scrutineeTypeTree =?= patternTypeTree
         // After matching and doing all subtype checks, we have to approximate all the type bindings
         // that we have found and seal them in a quoted.Type
         matchings.asOptionOfTuple.map { tup =>
           Tuple.fromArray(tup.toArray.map { // TODO improve performance
-            case x: SymBinding => internal.Constraints_approximation(summon[Context])(x.sym, !x.fromAbove).seal
+            case x: SymBinding => qctx.tasty.Constraints_approximation(summon[Context])(x.sym, !x.fromAbove).seal
             case x => x
           })
         }
@@ -190,13 +192,13 @@ object Matcher {
     private def hasFromAboveAnnotation(sym: Symbol) = sym.annots.exists(isFromAboveAnnotation)
 
     private def isPatternTypeAnnotation(tree: Tree): Boolean = tree match {
-      case New(tpt) => tpt.symbol == internal.Definitions_InternalQuotedMatcher_patternTypeAnnot
-      case annot => annot.symbol.owner == internal.Definitions_InternalQuotedMatcher_patternTypeAnnot
+      case New(tpt) => tpt.symbol == qctx.tasty.Definitions_InternalQuotedMatcher_patternTypeAnnot
+      case annot => annot.symbol.owner == qctx.tasty.Definitions_InternalQuotedMatcher_patternTypeAnnot
     }
 
     private def isFromAboveAnnotation(tree: Tree): Boolean = tree match {
-      case New(tpt) => tpt.symbol == internal.Definitions_InternalQuotedMatcher_fromAboveAnnot
-      case annot => annot.symbol.owner == internal.Definitions_InternalQuotedMatcher_fromAboveAnnot
+      case New(tpt) => tpt.symbol == qctx.tasty.Definitions_InternalQuotedMatcher_fromAboveAnnot
+      case annot => annot.symbol.owner == qctx.tasty.Definitions_InternalQuotedMatcher_fromAboveAnnot
     }
 
     /** Check that all trees match with `mtch` and concatenate the results with &&& */
@@ -250,22 +252,22 @@ object Matcher {
           /* Term hole */
           // Match a scala.internal.Quoted.patternHole typed as a repeated argument and return the scrutinee tree
           case (scrutinee @ Typed(s, tpt1), Typed(TypeApply(patternHole, tpt :: Nil), tpt2))
-              if patternHole.symbol == internal.Definitions_InternalQuotedMatcher_patternHole &&
+              if patternHole.symbol == qctx.tasty.Definitions_InternalQuotedMatcher_patternHole &&
                  s.tpe <:< tpt.tpe &&
                  tpt2.tpe.derivesFrom(defn.RepeatedParamClass) =>
             matched(scrutinee.seal)
 
           /* Term hole */
           // Match a scala.internal.Quoted.patternHole and return the scrutinee tree
           case (ClosedPatternTerm(scrutinee), TypeApply(patternHole, tpt :: Nil))
-              if patternHole.symbol == internal.Definitions_InternalQuotedMatcher_patternHole &&
+              if patternHole.symbol == qctx.tasty.Definitions_InternalQuotedMatcher_patternHole &&
                  scrutinee.tpe <:< tpt.tpe =>
             matched(scrutinee.seal)
 
           /* Higher order term hole */
           // Matches an open term and wraps it into a lambda that provides the free variables
           case (scrutinee, pattern @ Apply(TypeApply(Ident("higherOrderHole"), List(Inferred())), Repeated(args, _) :: Nil))
-              if pattern.symbol == internal.Definitions_InternalQuotedMatcher_higherOrderHole =>
+              if pattern.symbol == qctx.tasty.Definitions_InternalQuotedMatcher_higherOrderHole =>
 
             def bodyFn(lambdaArgs: List[Tree]): Tree = {
               val argsMap = args.map(_.symbol).zip(lambdaArgs.asInstanceOf[List[Term]]).toMap
@@ -323,7 +325,7 @@ object Matcher {
             fn1 =?= fn2 &&& args1 =?= args2
 
           case (Block(stats1, expr1), Block(binding :: stats2, expr2)) if isTypeBinding(binding) =>
-            qctx.tasty.internal.Constraints_add(summon[Context])(binding.symbol :: Nil)
+            qctx.tasty.Constraints_add(summon[Context])(binding.symbol :: Nil)
             matched(new SymBinding(binding.symbol, hasFromAboveAnnotation(binding.symbol))) &&& Block(stats1, expr1) =?= Block(stats2, expr2)
 
           /* Match block */
@@ -340,7 +342,7 @@ object Matcher {
 
           case (scrutinee, Block(typeBindings, expr2)) if typeBindings.forall(isTypeBinding) =>
             val bindingSymbols = typeBindings.map(_.symbol)
-            qctx.tasty.internal.Constraints_add(summon[Context])(bindingSymbols)
+            qctx.tasty.Constraints_add(summon[Context])(bindingSymbols)
             bindingSymbols.foldRight(scrutinee =?= expr2)((x, acc) => matched(new SymBinding(x, hasFromAboveAnnotation(x))) &&& acc)
 
           /* Match if */

library/src-bootstrapped/scala/internal/quoted/Type.scala

@@ -14,7 +14,7 @@ final class Type[Tree](val typeTree: Tree, val scopeId: Int) extends scala.quote
 
   /** View this expression `quoted.Type[T]` as a `TypeTree` */
   def unseal(using qctx: QuoteContext): qctx.tasty.TypeTree =
-    if (qctx.tasty.internal.compilerId != scopeId)
+    if (scala.internal.tasty.CompilerInterface.leaked(qctx).tasty.compilerId != scopeId)
       throw new scala.quoted.ScopeException("Cannot call `scala.quoted.staging.run(...)` within a macro or another `run(...)`")
     typeTree.asInstanceOf[qctx.tasty.TypeTree]
 
@@ -39,7 +39,7 @@ object Type {
    */
   def unapply[TypeBindings <: Tuple, Tup <: Tuple](scrutineeType: scala.quoted.Type[_])(using patternType: scala.quoted.Type[_],
         hasTypeSplices: Boolean, qctx: QuoteContext): Option[Tup] = {
-    new Matcher.QuoteMatcher[qctx.type].typeTreeMatch(scrutineeType.unseal, patternType.unseal, hasTypeSplices).asInstanceOf[Option[Tup]]
+    new Matcher.QuoteMatcher[qctx.type](qctx).typeTreeMatch(scrutineeType.unseal, patternType.unseal, hasTypeSplices).asInstanceOf[Option[Tup]]
   }
 
   def Unit: QuoteContext ?=> quoted.Type[Unit] =

library/src-bootstrapped/scala/internal/quoted/Unpickler.scala

@@ -12,16 +12,16 @@ object Unpickler {
    *  replacing splice nodes with `args`
    */
   def unpickleExpr[T](repr: PickledQuote, args: PickledArgs): QuoteContext ?=> Expr[T] =
-    val ctx = summon[QuoteContext]
-    val tree = ctx.tasty.internal.unpickleExpr(repr, args)
-    new scala.internal.quoted.Expr(tree, ctx.tasty.internal.compilerId).asInstanceOf[Expr[T]]
+    val qctx = scala.internal.tasty.CompilerInterface.leaked(summon[QuoteContext])
+    val tree = qctx.tasty.unpickleExpr(repr, args)
+    new scala.internal.quoted.Expr(tree, qctx.tasty.compilerId).asInstanceOf[Expr[T]]
 
   /** Unpickle `repr` which represents a pickled `Type` tree,
    *  replacing splice nodes with `args`
    */
   def unpickleType[T](repr: PickledQuote, args: PickledArgs): QuoteContext ?=> Type[T] =
-    val ctx = summon[QuoteContext]
-    val tree = ctx.tasty.internal.unpickleType(repr, args)
-    new scala.internal.quoted.Type(tree, ctx.tasty.internal.compilerId).asInstanceOf[Type[T]]
+    val qctx = scala.internal.tasty.CompilerInterface.leaked(summon[QuoteContext])
+    val tree = qctx.tasty.unpickleType(repr, args)
+    new scala.internal.quoted.Type(tree, qctx.tasty.compilerId).asInstanceOf[Type[T]]
 
 }

library/src-bootstrapped/scala/quoted/Expr.scala

@@ -75,7 +75,8 @@ object Expr {
    *   Otherwise returns `expr`.
    */
   def betaReduce[T](expr: Expr[T])(using qctx: QuoteContext): Expr[T] =
-    qctx.tasty.internal.betaReduce(expr.unseal) match
+    val qctx2 = scala.internal.tasty.CompilerInterface.leaked(qctx)
+    qctx2.tasty.betaReduce(expr.unseal) match
       case Some(expr1) => expr1.seal.asInstanceOf[Expr[T]]
       case _ => expr
 

library/src-bootstrapped/scala/quoted/Lambda.scala

@@ -19,12 +19,12 @@ object Lambda {
     import qctx.tasty._
     val argTypes = functionType.unseal.tpe match
       case AppliedType(_, functionArguments) => functionArguments.init.asInstanceOf[List[Type]]
-    qctx.tasty.internal.lambdaExtractor(expr.unseal, argTypes).map { fn =>
+    val qctx2 = scala.internal.tasty.CompilerInterface.leaked(qctx)
+    qctx2.tasty.lambdaExtractor(expr.unseal, argTypes).map { fn =>
       def f(args: Tuple.Map[Args, Expr]): Expr[Res] =
         fn(args.toArray.toList.map(_.asInstanceOf[Expr[Any]].unseal)).seal.asInstanceOf[Expr[Res]]
       tg.untupled(f)
     }
-
   }
 
 }

library/src-non-bootstrapped/scala/internal/quoted/Expr.scala

@@ -19,7 +19,7 @@ import scala.quoted._
   }
 
   def unseal(using qctx: QuoteContext): qctx.tasty.Term =
-    if (qctx.tasty.internal.compilerId != scopeId)
+    if (scala.internal.tasty.CompilerInterface.leaked(qctx).tasty.compilerId != scopeId)
       throw new scala.quoted.ScopeException("Cannot call `scala.quoted.staging.run(...)` within a macro or another `run(...)`")
     tree.asInstanceOf[qctx.tasty.Term]
 

library/src-non-bootstrapped/scala/internal/quoted/Type.scala

@@ -14,7 +14,7 @@ final class Type[Tree](val typeTree: Tree, val scopeId: Int) extends scala.quote
 
   /** View this expression `quoted.Type[T]` as a `TypeTree` */
   def unseal(using qctx: QuoteContext): qctx.tasty.TypeTree =
-    if (qctx.tasty.internal.compilerId != scopeId)
+    if (scala.internal.tasty.CompilerInterface.leaked(qctx).tasty.compilerId != scopeId)
       throw new scala.quoted.ScopeException("Cannot call `scala.quoted.staging.run(...)` within a macro or another `run(...)`")
     typeTree.asInstanceOf[qctx.tasty.TypeTree]