Merge pull request #8497 from dotty-staging/handle-quotecontext-paths-explicitly

Handle QuoteContext paths explicitly

Author: nicolasstucki

compiler/src/dotty/tools/dotc/core/Definitions.scala

@@ -690,6 +690,7 @@ class Definitions {
   @tu lazy val InternalQuotedModule: Symbol = ctx.requiredModule("scala.internal.quoted.CompileTime")
     @tu lazy val InternalQuoted_exprQuote  : Symbol = InternalQuotedModule.requiredMethod("exprQuote")
     @tu lazy val InternalQuoted_exprSplice : Symbol = InternalQuotedModule.requiredMethod("exprSplice")
+    @tu lazy val InternalQuoted_exprNestedSplice : Symbol = InternalQuotedModule.requiredMethod("exprNestedSplice")
     @tu lazy val InternalQuoted_typeQuote  : Symbol = InternalQuotedModule.requiredMethod("typeQuote")
     @tu lazy val InternalQuoted_patternHole: Symbol = InternalQuotedModule.requiredMethod("patternHole")
     @tu lazy val InternalQuoted_patternBindHoleAnnot: ClassSymbol = InternalQuotedModule.requiredClass("patternBindHole")

compiler/src/dotty/tools/dotc/printing/RefinedPrinter.scala

@@ -385,7 +385,7 @@ class RefinedPrinter(_ctx: Context) extends PlainPrinter(_ctx) {
           }
         else if (!printDebug && fun.hasType && fun.symbol == defn.InternalQuoted_exprQuote)
           keywordStr("'{") ~ toTextGlobal(args, ", ") ~ keywordStr("}")
-        else if (!printDebug && fun.hasType && fun.symbol == defn.InternalQuoted_exprSplice)
+        else if (!printDebug && fun.hasType && (fun.symbol == defn.InternalQuoted_exprSplice || fun.symbol == defn.InternalQuoted_exprNestedSplice))
           keywordStr("${") ~ toTextGlobal(args, ", ") ~ keywordStr("}")
         else
           toTextLocal(fun)

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

@@ -80,11 +80,16 @@ class PCPCheckAndHeal(@constructorOnly ictx: Context) extends TreeMapWithStages(
   protected def transformSplice(body: Tree, splice: Tree)(implicit ctx: Context): Tree = {
     val body1 = transform(body)(spliceContext)
     splice match {
-      case Apply(fun @ TypeApply(_, _ :: qctx :: Nil), _) if splice.isTerm =>
+      case Apply(fun @ TypeApply(_, _ :: Nil), _) if splice.isTerm =>
         // Type of the splice itsel must also be healed
         // internal.Quoted.expr[F[T]](... T ...)  -->  internal.Quoted.expr[F[$t]](... T ...)
         val tp = checkType(splice.sourcePos).apply(splice.tpe.widenTermRefExpr)
-        cpy.Apply(splice)(cpy.TypeApply(fun)(fun.fun, tpd.TypeTree(tp) :: qctx :: Nil), body1 :: Nil)
+        cpy.Apply(splice)(cpy.TypeApply(fun)(fun.fun, tpd.TypeTree(tp) :: Nil), body1 :: Nil)
+      case Apply(f @ Apply(fun @ TypeApply(_, _), qctx :: Nil), _) if splice.isTerm =>
+        // Type of the splice itsel must also be healed
+        // internal.Quoted.expr[F[T]](... T ...)  -->  internal.Quoted.expr[F[$t]](... T ...)
+        val tp = checkType(splice.sourcePos).apply(splice.tpe.widenTermRefExpr)
+        cpy.Apply(splice)(cpy.Apply(f)(cpy.TypeApply(fun)(fun.fun, tpd.TypeTree(tp) :: Nil), qctx :: Nil), body1 :: Nil)
       case splice: Select =>
         val tagRef = getQuoteTypeTags.getTagRef(splice.qualifier.tpe.asInstanceOf[TermRef])
         ref(tagRef).withSpan(splice.span)

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

@@ -343,7 +343,7 @@ class ReifyQuotes extends MacroTransform {
             val body = capturers(tree.symbol).apply(tree)
             val splice: Tree =
               if (tree.isType) body.select(tpnme.splice)
-              else ref(defn.InternalQuoted_exprSplice).appliedToTypes(List(tree.tpe, defn.QuoteContextClass.typeRef)).appliedTo(body)
+              else ref(defn.InternalQuoted_exprSplice).appliedToType(tree.tpe).appliedTo(body)
 
             transformSplice(body, splice)
 

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

@@ -219,7 +219,7 @@ class SymUtils(val self: Symbol) extends AnyVal {
 
   /** Is symbol a splice operation? */
   def isSplice(implicit ctx: Context): Boolean =
-    self == defn.InternalQuoted_exprSplice || self == defn.QuotedType_splice
+    self == defn.InternalQuoted_exprSplice || self == defn.InternalQuoted_exprNestedSplice || self == defn.QuotedType_splice
 
   def isCollectiveExtensionClass(using Context): Boolean =
     self.is(ModuleClass) && self.sourceModule.is(Extension, butNot = Method)

compiler/src/dotty/tools/dotc/typer/QuotesAndSplices.scala

@@ -80,7 +80,7 @@ trait QuotesAndSplices {
           spliceContext.retractMode(Mode.QuotedPattern).withOwner(spliceOwner(ctx)))
         val baseType = pat.tpe.baseType(defn.QuotedExprClass)
         val argType = if baseType != NoType then baseType.argTypesHi.head else defn.NothingType
-        ref(defn.InternalQuoted_exprSplice).appliedToTypes(List(argType, defn.QuoteContextClass.typeRef)).appliedTo(pat)
+        ref(defn.InternalQuoted_exprSplice).appliedToType(argType).appliedTo(pat)
       }
       else {
         ctx.error(i"Type must be fully defined.\nConsider annotating the splice using a type ascription:\n  ($tree: XYZ).", tree.expr.sourcePos)
@@ -113,7 +113,12 @@ trait QuotesAndSplices {
       val qctxParam = untpd.makeParameter(qctxParamName, qctxParamTpt, untpd.Modifiers(Given))
       val expr = untpd.Function(List(qctxParam), tree.expr).withSpan(tree.span)
 
-      typedApply(untpd.Apply(untpd.ref(defn.InternalQuoted_exprSplice.termRef), expr), pt)(ctx1).withSpan(tree.span)
+      val internalSplice =
+        outerQctx match
+          case Some(qctxRef) => untpd.Apply(untpd.Apply(untpd.ref(defn.InternalQuoted_exprNestedSplice.termRef), qctxRef), expr)
+          case _ => untpd.Apply(untpd.ref(defn.InternalQuoted_exprSplice.termRef), expr)
+
+      typedApply(internalSplice, pt)(ctx1).withSpan(tree.span)
     }
   }
 
@@ -210,10 +215,7 @@ trait QuotesAndSplices {
         case Typed(Apply(fn, pat :: Nil), tpt) if fn.symbol == defn.InternalQuoted_exprSplice && !tpt.tpe.derivesFrom(defn.RepeatedParamClass) =>
           val tpt1 = transform(tpt) // Transform type bindings
           val exprTpt = AppliedTypeTree(TypeTree(defn.QuotedExprClass.typeRef), tpt1 :: Nil)
-          val newSplice =
-            ref(defn.InternalQuoted_exprSplice)
-              .appliedToTypes(List(tpt1.tpe, defn.QuoteContextClass.typeRef))
-              .appliedTo(Typed(pat, exprTpt))
+          val newSplice = ref(defn.InternalQuoted_exprSplice).appliedToType(tpt1.tpe).appliedTo(Typed(pat, exprTpt))
           transform(newSplice)
         case Apply(fn, pat :: Nil) if fn.symbol == defn.InternalQuoted_exprSplice =>
           try ref(defn.InternalQuoted_patternHole.termRef).appliedToType(tree.tpe).withSpan(tree.span)

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

@@ -0,0 +1,54 @@
+package scala.internal.quoted
+
+import scala.annotation.{Annotation, compileTimeOnly}
+import scala.quoted._
+
+@compileTimeOnly("Illegal reference to `scala.internal.quoted.CompileTime`")
+object CompileTime {
+
+  /** A term quote is desugared by the compiler into a call to this method */
+  @compileTimeOnly("Illegal reference to `scala.internal.quoted.CompileTime.exprQuote`")
+  def exprQuote[T](x: T): QuoteContext ?=> Expr[T] = ???
+
+  /** A term splice is desugared by the compiler into a call to this method */
+  @compileTimeOnly("Illegal reference to `scala.internal.quoted.CompileTime.exprSplice`")
+  def exprSplice[T](x: QuoteContext ?=> Expr[T]): T = ???
+
+  /** A term splice nested within a quote is desugared by the compiler into a call to this method.
+   *  `ctx` is the `QuoteContext` that the quote of this splice uses.
+   */
+  @compileTimeOnly("Illegal reference to `scala.internal.quoted.CompileTime.exprNestedSplice`")
+  def exprNestedSplice[T](ctx: QuoteContext)(x: ctx.NestedContext ?=> Expr[T]): T = ???
+
+  /** A type quote is desugared by the compiler into a call to this method */
+  @compileTimeOnly("Illegal reference to `scala.internal.quoted.CompileTime.typeQuote`")
+  def typeQuote[T <: AnyKind]: Type[T] = ???
+
+  /** A splice in a quoted pattern is desugared by the compiler into a call to this method */
+  @compileTimeOnly("Illegal reference to `scala.internal.quoted.CompileTime.patternHole`")
+  def patternHole[T]: T = ???
+
+  /** A splice of a name in a quoted pattern is desugared by wrapping getting this annotation */
+  @compileTimeOnly("Illegal reference to `scala.internal.quoted.CompileTime.patternBindHole`")
+  class patternBindHole extends Annotation
+
+  /** A splice of a name in a quoted pattern is that marks the definition of a type splice */
+  @compileTimeOnly("Illegal reference to `scala.internal.quoted.CompileTime.patternType`")
+  class patternType extends Annotation
+
+  /** A type pattern that must be aproximated from above */
+  @compileTimeOnly("Illegal reference to `scala.internal.quoted.CompileTime.fromAbove`")
+  class fromAbove extends Annotation
+
+  /** Artifact of pickled type splices
+   *
+   *  During quote reification a quote `'{ ... F[$t] ... }` will be transformed into
+   *  `'{ @quoteTypeTag type T$1 = $t ... F[T$1] ... }` to have a tree for `$t`.
+   *  This artifact is removed during quote unpickling.
+   *
+   *  See ReifyQuotes.scala and PickledQuotes.scala
+   */
+  @compileTimeOnly("Illegal reference to `scala.internal.quoted.CompileTime.quoteTypeTag`")
+  class quoteTypeTag extends Annotation
+
+}

library/src/scala/internal/quoted/CompileTime.scala renamed to library/src-non-bootstrapped/scala/internal/quoted/CompileTime.scala

@@ -4,13 +4,13 @@ def test(using QuoteContext) = {
 
   '{
     val qctx: QuoteContext = ???
-    given qctx.type = qctx
+    given x1 as qctx.type = qctx
 
     val b = '{3}
 
     '{
       val qctx: QuoteContext = ???
-      given qctx.type = qctx
+      given x2 as qctx.type = qctx
 
       b // error
       ${b}

tests/neg/i4044b.scala

@@ -0,0 +1,13 @@
+
+import scala.quoted._
+
+inline def power(x: Double, inline n: Int) = ${ powerCode1('x, 'n) }
+
+private def powerCode1(using qctx: QuoteContext)(x: Expr[Double], n: Expr[Int]): Expr[Double] =
+  powerCode(x, n.value)
+
+private def powerCode(using qctx: QuoteContext)(x: Expr[Double], n: Int): Expr[Double] =
+  if (n == 0) Expr(1.0)
+  else if (n == 1) x
+  else if (n % 2 == 0) '{ val y = $x * $x; ${ powerCode('y, n / 2) } }
+  else '{ $x * ${ powerCode(x, n - 1) } }