Merge pull request #6881 from dotty-staging/contextualize-splices

Contextualize quote and splice internals

Author: nicolasstucki

community-build/community-projects/scalatest

@@ -14,6 +14,7 @@ import dotty.tools.dotc.core.Types._
 import dotty.tools.dotc.core.tasty.TreePickler.Hole
 import dotty.tools.dotc.core.tasty.{PositionPickler, TastyPickler, TastyPrinter, TastyString}
 import dotty.tools.dotc.core.tasty.TreeUnpickler.UnpickleMode
+import dotty.tools.dotc.tastyreflect.ReflectionImpl
 
 import scala.internal.quoted._
 import scala.reflect.ClassTag
@@ -47,7 +48,7 @@ object PickledQuotes {
       forceAndCleanArtefacts.transform(unpickled)
     case expr: TastyTreeExpr[Tree] @unchecked => healOwner(expr.tree)
     case expr: FunctionAppliedTo[_] =>
-      functionAppliedTo(quotedExprToTree(expr.f), expr.args.map(arg => quotedExprToTree(arg)).toList)
+      functionAppliedTo(quotedExprToTree(expr.f), expr.args.map(arg => quotedExprToTree(arg(new scala.quoted.QuoteContext(ReflectionImpl(ctx))))).toList)
   }
 
   /** Transform the expression into its fully spliced TypeTree */

compiler/src/dotty/tools/dotc/core/quoted/PickledQuotes.scala

@@ -1273,14 +1273,15 @@ class TreeUnpickler(reader: TastyReader,
       val args = until(end)(readTerm())
       val splice = splices(idx)
       def wrap(arg: Tree) =
-        if (arg.isTerm) new TastyTreeExpr(arg)
+        if (arg.isTerm) given (qctx: scala.quoted.QuoteContext) => new TastyTreeExpr(arg)
         else new TreeType(arg)
       val reifiedArgs = args.map(wrap)
       val filled = if (isType) {
         val quotedType = splice.asInstanceOf[Seq[Any] => quoted.Type[_]](reifiedArgs)
         PickledQuotes.quotedTypeToTree(quotedType)
       } else {
-        val quotedExpr = splice.asInstanceOf[Seq[Any] => quoted.Expr[_]](reifiedArgs)
+        val splice1 = splice.asInstanceOf[Seq[Any] => given scala.quoted.QuoteContext => quoted.Expr[_]]
+        val quotedExpr = splice1(reifiedArgs) given new scala.quoted.QuoteContext(tastyreflect.ReflectionImpl(ctx))
         PickledQuotes.quotedExprToTree(quotedExpr)
       }
       // We need to make sure a hole is created with the source file of the surrounding context, even if

compiler/src/dotty/tools/dotc/core/tasty/TreeUnpickler.scala

@@ -14,16 +14,19 @@ import dotty.tools.dotc.core.Decorators._
 import dotty.tools.dotc.tastyreflect.FromSymbol.{definitionFromSym, packageDefFromSym}
 import dotty.tools.dotc.parsing.Parsers.Parser
 import dotty.tools.dotc.typer.Implicits.{AmbiguousImplicits, DivergingImplicit, NoMatchingImplicits, SearchFailure, SearchFailureType}
-import dotty.tools.dotc.util.SourceFile
+import dotty.tools.dotc.util.{SourceFile, SourcePosition, Spans}
 
 import scala.tasty.reflect.Kernel
 
-class KernelImpl(val rootContext: core.Contexts.Context, val rootPosition: util.SourcePosition) extends Kernel {
+class KernelImpl(val rootContext: core.Contexts.Context) extends Kernel {
 
   private implicit def ctx: core.Contexts.Context = rootContext
 
   def settings: Settings = rootContext.settings
 
+  def rootPosition: util.SourcePosition =
+    tastyreflect.MacroExpansion.position.getOrElse(SourcePosition(rootContext.source, Spans.NoSpan))
+
   //
   // CONTEXT
   //

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

@@ -0,0 +1,18 @@
+package dotty.tools.dotc.tastyreflect
+
+import dotty.tools.dotc.ast.tpd
+import dotty.tools.dotc.core._
+import dotty.tools.dotc.core.Contexts._
+import dotty.tools.dotc.util.{Property, SourcePosition, Spans}
+
+object MacroExpansion {
+
+  private val MacroExpansionPosition = new Property.Key[SourcePosition]
+
+  def position(implicit ctx: Context): Option[SourcePosition] =
+    ctx.property(MacroExpansionPosition)
+
+  def context(inlinedFrom: tpd.Tree)(implicit ctx: Context): Context =
+    ctx.fresh.setProperty(MacroExpansionPosition, SourcePosition(inlinedFrom.source, inlinedFrom.span)).withSource(inlinedFrom.source)
+
+}

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

@@ -2,20 +2,17 @@ package dotty.tools.dotc.tastyreflect
 
 import dotty.tools.dotc.ast.tpd
 import dotty.tools.dotc.core._
-import dotty.tools.dotc.util.{SourcePosition, Spans}
+import dotty.tools.dotc.core.Contexts._
 
 import scala.quoted.show.SyntaxHighlight
 
 object ReflectionImpl {
 
   def apply(rootContext: Contexts.Context): scala.tasty.Reflection =
-    apply(rootContext, SourcePosition(rootContext.source, Spans.NoSpan))
-
-  def apply(rootContext: Contexts.Context, rootPosition: SourcePosition): scala.tasty.Reflection =
-    new scala.tasty.Reflection(new KernelImpl(rootContext, rootPosition))
+    new scala.tasty.Reflection(new KernelImpl(rootContext))
 
   def showTree(tree: tpd.Tree)(implicit ctx: Contexts.Context): String = {
-    val refl = new scala.tasty.Reflection(new KernelImpl(ctx, tree.sourcePos))
+    val refl = new scala.tasty.Reflection(new KernelImpl(MacroExpansion.context(tree)))
     val reflCtx = ctx.asInstanceOf[refl.Context]
     val reflTree = tree.asInstanceOf[refl.Tree]
     val syntaxHighlight =

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

@@ -177,7 +177,6 @@ class ReifyQuotes extends MacroTransform {
      */
     override protected def transformQuotation(body: Tree, quote: Tree)(implicit ctx: Context): Tree = {
       val isType = quote.symbol eq defn.InternalQuoted_typeQuote
-      assert(!(body.symbol.isSplice && (body.isInstanceOf[GenericApply[_]] || body.isInstanceOf[Select])))
       if (level > 0) {
         val body1 = nested(isQuote = true).transform(body)(quoteContext)
         super.transformQuotation(body1, quote)
@@ -209,35 +208,37 @@ class ReifyQuotes extends MacroTransform {
         qctx
       }
 
-      def liftedValue[T](value: T, name: TermName, qctx: Tree) =
-        ref(defn.LiftableModule).select(name).select("toExpr".toTermName).appliedTo(Literal(Constant(value))).select(nme.apply).appliedTo(qctx)
-
-      def pickleAsValue[T](value: T) = value match {
-        case null => ref(defn.QuotedExprModule).select("nullExpr".toTermName).appliedTo(qctx)
-        case _: Unit => ref(defn.QuotedExprModule).select("unitExpr".toTermName).appliedTo(qctx)
-        case _: Boolean => liftedValue(value, "Liftable_Boolean_delegate".toTermName, qctx)
-        case _: Byte => liftedValue(value, "Liftable_Byte_delegate".toTermName, qctx)
-        case _: Short => liftedValue(value, "Liftable_Short_delegate".toTermName, qctx)
-        case _: Int => liftedValue(value, "Liftable_Int_delegate".toTermName, qctx)
-        case _: Long => liftedValue(value, "Liftable_Long_delegate".toTermName, qctx)
-        case _: Float => liftedValue(value, "Liftable_Float_delegate".toTermName, qctx)
-        case _: Double => liftedValue(value, "Liftable_Double_delegate".toTermName, qctx)
-        case _: Char => liftedValue(value, "Liftable_Char_delegate".toTermName, qctx)
-        case _: String => liftedValue(value, "Liftable_String_delegate".toTermName, qctx)
+      def liftedValue[T](value: T, name: TermName) =
+        ref(defn.LiftableModule).select(name).select("toExpr".toTermName).appliedTo(Literal(Constant(value)))
+
+      def pickleAsValue[T](value: T) = {
+        value match {
+          case null => ref(defn.QuotedExprModule).select("nullExpr".toTermName)
+          case _: Unit => ref(defn.QuotedExprModule).select("unitExpr".toTermName)
+          case _: Boolean => liftedValue(value, "Liftable_Boolean_delegate".toTermName)
+          case _: Byte => liftedValue(value, "Liftable_Byte_delegate".toTermName)
+          case _: Short => liftedValue(value, "Liftable_Short_delegate".toTermName)
+          case _: Int => liftedValue(value, "Liftable_Int_delegate".toTermName)
+          case _: Long => liftedValue(value, "Liftable_Long_delegate".toTermName)
+          case _: Float => liftedValue(value, "Liftable_Float_delegate".toTermName)
+          case _: Double => liftedValue(value, "Liftable_Double_delegate".toTermName)
+          case _: Char => liftedValue(value, "Liftable_Char_delegate".toTermName)
+          case _: String => liftedValue(value, "Liftable_String_delegate".toTermName)
+        }
       }
 
       def pickleAsTasty() = {
         val meth =
           if (isType) ref(defn.Unpickler_unpickleType).appliedToType(originalTp)
           else ref(defn.Unpickler_unpickleExpr).appliedToType(originalTp.widen)
-        def wildcardQuotedType = defn.QuotedTypeClass.typeRef.appliedTo(WildcardType)
         val spliceResType =
-          if (isType) wildcardQuotedType
-          else defn.QuotedExprClass.typeRef.appliedTo(defn.AnyType) | wildcardQuotedType
-        meth.appliedTo(
-          liftList(PickledQuotes.pickleQuote(body).map(x => Literal(Constant(x))), defn.StringType),
-          liftList(splices, defn.FunctionType(1).appliedTo(defn.SeqType.appliedTo(defn.AnyType), spliceResType)))
+          if (isType) defn.QuotedTypeClass.typeRef.appliedTo(WildcardType)
+          else defn.FunctionType(1, isContextual = true).appliedTo(defn.QuoteContextClass.typeRef, defn.QuotedExprClass.typeRef.appliedTo(defn.AnyType)) | defn.QuotedTypeClass.typeRef.appliedTo(WildcardType)
+        val pickledQuoteStrings = liftList(PickledQuotes.pickleQuote(body).map(x => Literal(Constant(x))), defn.StringType)
+        val splicesList = liftList(splices, defn.FunctionType(1).appliedTo(defn.SeqType.appliedTo(defn.AnyType), spliceResType))
+        meth.appliedTo(pickledQuoteStrings, splicesList)
       }
+
       if (splices.nonEmpty) pickleAsTasty()
       else if (isType) {
         def tag(tagName: String) = ref(defn.QuotedTypeModule).select(tagName.toTermName).appliedTo(qctx)
@@ -316,7 +317,7 @@ class ReifyQuotes extends MacroTransform {
                 assert(tpw.isInstanceOf[ValueType])
                 val argTpe =
                   if (tree.isType) defn.QuotedTypeClass.typeRef.appliedTo(tpw)
-                  else defn.QuotedExprClass.typeRef.appliedTo(tpw)
+                  else defn.FunctionType(1, isContextual = true).appliedTo(defn.QuoteContextClass.typeRef, defn.QuotedExprClass.typeRef.appliedTo(tpw))
                 val selectArg = arg.select(nme.apply).appliedTo(Literal(Constant(i))).cast(argTpe)
                 val capturedArg = SyntheticValDef(UniqueName.fresh(tree.symbol.name.toTermName).toTermName, selectArg)
                 i += 1
@@ -357,7 +358,9 @@ class ReifyQuotes extends MacroTransform {
       val tree2 = transform(tree)
       capturers --= outer.localSymbols
 
-      seq(captured.result().valuesIterator.toList, tree2)
+      val captures = captured.result().valuesIterator.toList
+      if (captures.isEmpty) tree2
+      else Block(captures, tree2)
     }
 
     /** Returns true if this tree will be captured by `makeLambda`. Checks phase consistency and presence of capturer. */

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

@@ -41,15 +41,18 @@ object Splicer {
       val interpreter = new Interpreter(pos, classLoader)
       try {
         // Some parts of the macro are evaluated during the unpickling performed in quotedExprToTree
-        val interpretedExpr = interpreter.interpret[scala.quoted.Expr[Any]](tree)
-        interpretedExpr.fold(tree)(x => PickledQuotes.quotedExprToTree(x))
+        val interpretedExpr = interpreter.interpret[scala.quoted.QuoteContext => scala.quoted.Expr[Any]](tree)
+        interpretedExpr.fold(tree)(macroClosure => PickledQuotes.quotedExprToTree(macroClosure(new scala.quoted.QuoteContext(ReflectionImpl(ctx)))))
       }
       catch {
+        case ex: StopInterpretation =>
+          ctx.error(ex.msg, ex.pos)
+          EmptyTree
         case NonFatal(ex) =>
           val msg =
             s"""Failed to evaluate macro.
                |  Caused by ${ex.getClass}: ${if (ex.getMessage == null) "" else ex.getMessage}
-               |    ${ex.getStackTrace.takeWhile(_.getClassName != "dotty.tools.dotc.transform.Splicer$").init.mkString("\n    ")}
+               |    ${ex.getStackTrace.takeWhile(_.getClassName != "dotty.tools.dotc.transform.Splicer$").drop(1).mkString("\n    ")}
              """.stripMargin
           ctx.error(msg, pos)
           EmptyTree
@@ -65,19 +68,24 @@ object Splicer {
   def checkValidMacroBody(tree: Tree)(implicit ctx: Context): Unit = tree match {
     case Quoted(_) => // ok
     case _ =>
-      def checkValidStat(tree: Tree): Unit = tree match {
+      type Env = Set[Symbol]
+
+      def checkValidStat(tree: Tree) given Env: Env = tree match {
         case tree: ValDef if tree.symbol.is(Synthetic) =>
           // Check val from `foo(j = x, i = y)` which it is expanded to
           // `val j$1 = x; val i$1 = y; foo(i = i$1, j = j$1)`
           checkIfValidArgument(tree.rhs)
+          the[Env] + tree.symbol
         case _ =>
           ctx.error("Macro should not have statements", tree.sourcePos)
+          the[Env]
       }
-      def checkIfValidArgument(tree: Tree): Unit = tree match {
+
+      def checkIfValidArgument(tree: Tree) given Env: Unit = tree match {
         case Block(Nil, expr) => checkIfValidArgument(expr)
         case Typed(expr, _) => checkIfValidArgument(expr)
 
-        case Apply(TypeApply(fn, _), quoted :: Nil) if fn.symbol == defn.InternalQuoted_exprQuote =>
+        case Apply(Select(Apply(fn, quoted :: Nil), nme.apply), _) if fn.symbol == defn.InternalQuoted_exprQuote =>
           // OK
 
         case TypeApply(fn, quoted :: Nil) if fn.symbol == defn.InternalQuoted_typeQuote =>
@@ -101,7 +109,7 @@ object Splicer {
         case SeqLiteral(elems, _) =>
           elems.foreach(checkIfValidArgument)
 
-        case tree: Ident if tree.symbol.is(Inline) || tree.symbol.is(Synthetic) =>
+        case tree: Ident if tree.symbol.is(Inline) || the[Env].contains(tree.symbol) =>
           // OK
 
         case _ =>
@@ -114,10 +122,14 @@ object Splicer {
               | * Literal values of primitive types
               |""".stripMargin, tree.sourcePos)
       }
-      def checkIfValidStaticCall(tree: Tree): Unit = tree match {
+
+      def checkIfValidStaticCall(tree: Tree) given Env: Unit = tree match {
+        case closureDef(ddef @ DefDef(_, Nil, (ev :: Nil) :: Nil, _, _)) if ddef.symbol.info.isContextualMethod =>
+          checkIfValidStaticCall(ddef.rhs) given (the[Env] + ev.symbol)
+
         case Block(stats, expr) =>
-          stats.foreach(checkValidStat)
-          checkIfValidStaticCall(expr)
+          val newEnv = stats.foldLeft(the[Env])((env, stat) => checkValidStat(stat) given env)
+          checkIfValidStaticCall(expr) given newEnv
 
         case Typed(expr, _) =>
           checkIfValidStaticCall(expr)
@@ -126,6 +138,8 @@ object Splicer {
             if (fn.symbol.isConstructor && fn.symbol.owner.owner.is(Package)) ||
                fn.symbol.is(Module) || fn.symbol.isStatic ||
                (fn.qualifier.symbol.is(Module) && fn.qualifier.symbol.isStatic) =>
+          if (fn.symbol.flags.is(Inline))
+            ctx.error("Macro cannot be implemented with an `inline` method", fn.sourcePos)
           args.flatten.foreach(checkIfValidArgument)
 
         case _ =>
@@ -136,35 +150,29 @@ object Splicer {
               |""".stripMargin, tree.sourcePos)
       }
 
-      checkIfValidStaticCall(tree)
+      checkIfValidStaticCall(tree) given Set.empty
   }
 
   /** Tree interpreter that evaluates the tree */
   private class Interpreter(pos: SourcePosition, classLoader: ClassLoader)(implicit ctx: Context) {
 
-    type Env = Map[Name, Object]
+    type Env = Map[Symbol, Object]
 
     /** Returns the interpreted result of interpreting the code a call to the symbol with default arguments.
      *  Return Some of the result or None if some error happen during the interpretation.
      */
     def interpret[T](tree: Tree)(implicit ct: ClassTag[T]): Option[T] = {
-      try {
-        interpretTree(tree)(Map.empty) match {
-          case obj: T => Some(obj)
-          case obj =>
-            // TODO upgrade to a full type tag check or something similar
-            ctx.error(s"Interpreted tree returned a result of an unexpected type. Expected ${ct.runtimeClass} but was ${obj.getClass}", pos)
-            None
-        }
-      } catch {
-        case ex: StopInterpretation =>
-          ctx.error(ex.msg, ex.pos)
+      interpretTree(tree)(Map.empty) match {
+        case obj: T => Some(obj)
+        case obj =>
+          // TODO upgrade to a full type tag check or something similar
+          ctx.error(s"Interpreted tree returned a result of an unexpected type. Expected ${ct.runtimeClass} but was ${obj.getClass}", pos)
           None
       }
     }
 
     def interpretTree(tree: Tree)(implicit env: Env): Object = tree match {
-      case Apply(TypeApply(fn, _), quoted :: Nil) if fn.symbol == defn.InternalQuoted_exprQuote =>
+      case Apply(Select(Apply(TypeApply(fn, _), quoted :: Nil), nme.apply), _) if fn.symbol == defn.InternalQuoted_exprQuote =>
         val quoted1 = quoted match {
           case quoted: Ident if quoted.symbol.isAllOf(InlineByNameProxy) =>
             // inline proxy for by-name parameter
@@ -199,14 +207,17 @@ object Splicer {
             val staticMethodCall = interpretedStaticMethodCall(fn.qualifier.symbol.moduleClass, fn.symbol)
             staticMethodCall(args.flatten.map(interpretTree))
           }
-        } else if (env.contains(fn.name)) {
-          env(fn.name)
+        } else if (env.contains(fn.symbol)) {
+          env(fn.symbol)
         } else if (tree.symbol.is(InlineProxy)) {
           interpretTree(tree.symbol.defTree.asInstanceOf[ValOrDefDef].rhs)
         } else {
           unexpectedTree(tree)
         }
 
+      case closureDef((ddef @ DefDef(_, _, (arg :: Nil) :: Nil, _, _))) =>
+        (obj: AnyRef) => interpretTree(ddef.rhs) given env.updated(arg.symbol, obj)
+
       // Interpret `foo(j = x, i = y)` which it is expanded to
       // `val j$1 = x; val i$1 = y; foo(i = i$1, j = j$1)`
       case Block(stats, expr) => interpretBlock(stats, expr)
@@ -228,7 +239,7 @@ object Splicer {
       var unexpected: Option[Object] = None
       val newEnv = stats.foldLeft(env)((accEnv, stat) => stat match {
         case stat: ValDef =>
-          accEnv.updated(stat.name, interpretTree(stat.rhs)(accEnv))
+          accEnv.updated(stat.symbol, interpretTree(stat.rhs)(accEnv))
         case stat =>
           if (unexpected.isEmpty)
             unexpected = Some(unexpectedTree(stat))
@@ -250,7 +261,7 @@ object Splicer {
       args.toSeq
 
     private def interpretQuoteContext()(implicit env: Env): Object =
-      new scala.quoted.QuoteContext(ReflectionImpl(ctx, pos))
+      new scala.quoted.QuoteContext(ReflectionImpl(ctx))
 
     private def interpretedStaticMethodCall(moduleClass: Symbol, fn: Symbol)(implicit env: Env): List[Object] => Object = {
       val (inst, clazz) =
@@ -339,10 +350,13 @@ object Splicer {
           throw new StopInterpretation(sw.toString, pos)
         case ex: InvocationTargetException =>
           val sw = new StringWriter()
-          sw.write("An exception occurred while executing macro expansion\n")
+          sw.write("An exception occurred while executing macro expansion: ")
           sw.write(ex.getTargetException.getMessage)
           sw.write("\n")
-          ex.getTargetException.printStackTrace(new PrintWriter(sw))
+          for (stack <- ex.getTargetException.getStackTrace.iterator.takeWhile(_.getClassName != this.getClass.getName).drop(1)) {
+            sw.write(stack.toString)
+            sw.write("\n")
+          }
           sw.write("\n")
           throw new StopInterpretation(sw.toString, pos)
       }
@@ -404,11 +418,12 @@ object Splicer {
       allParams.map(paramClass)
     }
 
-    /** Exception that stops interpretation if some issue is found */
-    private class StopInterpretation(val msg: String, val pos: SourcePosition) extends Exception
 
   }
 
+  /** Exception that stops interpretation if some issue is found */
+  private class StopInterpretation(val msg: String, val pos: SourcePosition) extends Exception
+
   object Call {
     /** Matches an expression that is either a field access or an application
      *  It retruns a TermRef containing field accessed or a method reference and the arguments passed to it.