Merge pull request #7600 from dotty-staging/fix-#7264a

Fix #7264: Propagate prototypes in quoted type patterns

Author: odersky

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

@@ -97,26 +97,25 @@ trait QuotesAndSplices {
  ctx.warning("Canceled quote directly inside a splice. ${ '[ XYZ ] } is equivalent to XYZ.", tree.sourcePos)
  case _ =>
  }
+
  if (ctx.mode.is(Mode.QuotedPattern) && level == 1)
- if (isFullyDefined(pt, ForceDegree.all)) {
- ctx.error(i"Spliced type pattern must not be fully defined. Consider using $pt directly", tree.expr.sourcePos)
- tree.withType(UnspecifiedErrorType)
- }
- else {
- def spliceOwner(ctx: Context): Symbol =
- if (ctx.mode.is(Mode.QuotedPattern)) spliceOwner(ctx.outer) else ctx.owner
- val name = tree.expr match {
- case Ident(name) => ("$" + name).toTypeName
- case expr =>
- ctx.error("expected a name binding", expr.sourcePos)
- "$error".toTypeName
- }
- val typeSym = ctx.newSymbol(spliceOwner(ctx), name, EmptyFlags, TypeBounds.empty, NoSymbol, tree.expr.span)
- typeSym.addAnnotation(Annotation(New(ref(defn.InternalQuoted_patternBindHoleAnnot.typeRef)).withSpan(tree.expr.span)))
- val pat = typedPattern(tree.expr, defn.QuotedTypeClass.typeRef.appliedTo(typeSym.typeRef))(
- spliceContext.retractMode(Mode.QuotedPattern).withOwner(spliceOwner(ctx)))
- pat.select(tpnme.splice)
+ def spliceOwner(ctx: Context): Symbol =
+ if (ctx.mode.is(Mode.QuotedPattern)) spliceOwner(ctx.outer) else ctx.owner
+ val name = tree.expr match {
+ case Ident(name) => ("$" + name).toTypeName
+ case expr =>
+ ctx.error("expected a name binding", expr.sourcePos)
+ "$error".toTypeName
  }
+
+ val typeSymInfo = pt match
+ case pt: TypeBounds => pt
+ case _ => TypeBounds.empty
+ val typeSym = ctx.newSymbol(spliceOwner(ctx), name, EmptyFlags, typeSymInfo, NoSymbol, tree.expr.span)
+ typeSym.addAnnotation(Annotation(New(ref(defn.InternalQuoted_patternBindHoleAnnot.typeRef)).withSpan(tree.expr.span)))
+ val pat = typedPattern(tree.expr, defn.QuotedTypeClass.typeRef.appliedTo(typeSym.typeRef))(
+ spliceContext.retractMode(Mode.QuotedPattern).withOwner(spliceOwner(ctx)))
+ pat.select(tpnme.splice)
  else
  typedSelect(untpd.Select(tree.expr, tpnme.splice), pt)(spliceContext).withSpan(tree.span)
  }
@@ -191,11 +190,13 @@ trait QuotesAndSplices {
  patBuf += pat1
  }
  case Select(pat, _) if tree.symbol == defn.QuotedType_splice =>
- val sym = tree.tpe.dealias.typeSymbol.asType
- val tdef = TypeDef(sym).withSpan(sym.span)
- freshTypeBindingsBuff += transformTypeBindingTypeDef(tdef, freshTypePatBuf)
- TypeTree(tree.tpe.dealias).withSpan(tree.span)
-
+ val sym = tree.tpe.dealias.typeSymbol
+ if sym.exists then
+ val tdef = TypeDef(sym.asType).withSpan(sym.span)
+ freshTypeBindingsBuff += transformTypeBindingTypeDef(tdef, freshTypePatBuf)
+ TypeTree(tree.tpe.dealias).withSpan(tree.span)
+ else
+ tree
  case ddef: ValOrDefDef =>
  if (ddef.symbol.hasAnnotation(defn.InternalQuoted_patternBindHoleAnnot)) {
  val bindingType = ddef.symbol.info match {
@@ -317,13 +318,16 @@ trait QuotesAndSplices {
  ctx.error(missingArgMsg(qctx, defn.QuoteContextClass.typeRef, ""), ctx.source.atSpan(tree.span))
 
  val quoted = tree.quoted
- val exprPt = pt.baseType(defn.QuotedExprClass)
+ val exprPt = pt.baseType(if quoted.isType then defn.QuotedTypeClass else defn.QuotedExprClass)
  val quotedPt = exprPt.argInfos.headOption match {
  case Some(argPt: ValueType) => argPt // excludes TypeBounds
  case _ => defn.AnyType
  }
  val quoted0 = desugar.quotedPattern(quoted, untpd.TypedSplice(TypeTree(quotedPt)))
- val quoted1 = typedExpr(quoted0, WildcardType)(quoteContext.addMode(Mode.QuotedPattern))
+ val quoteCtx = quoteContext.addMode(Mode.QuotedPattern)
+ val quoted1 =
+ if quoted.isType then typedType(quoted0, WildcardType)(quoteCtx)
+ else typedExpr(quoted0, WildcardType)(quoteCtx)
 
  val (typeBindings, shape, splices) = splitQuotePattern(quoted1)
 

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

@@ -1389,8 +1389,10 @@ class Typer extends Namer
  def typedArg(arg: untpd.Tree, tparam: ParamInfo) = {
  def tparamBounds = tparam.paramInfoAsSeenFrom(tpt1.tpe.appliedTo(tparams.map(_ => TypeBounds.empty)))
  val (desugaredArg, argPt) =
- if (ctx.mode is Mode.Pattern)
+ if ctx.mode.is(Mode.Pattern) then
  (if (untpd.isVarPattern(arg)) desugar.patternVar(arg) else arg, tparamBounds)
+ else if ctx.mode.is(Mode.QuotedPattern) then
+ (arg, tparamBounds)
  else
  (arg, WildcardType)
  if (tpt1.symbol.isClass)
@@ -2177,7 +2179,7 @@ class Typer extends Namer
 
  /** Typecheck and adapt tree, returning a typed tree. Parameters as for `typedUnadapted` */
  def typed(tree: untpd.Tree, pt: Type, locked: TypeVars)(implicit ctx: Context): Tree =
- trace(i"typing $tree", typr, show = true) {
+ trace(i"typing $tree, pt = $pt", typr, show = true) {
  record(s"typed $getClass")
  record("typed total")
  assertPositioned(tree)
@@ -3030,7 +3032,7 @@ class Typer extends Namer
  tree.tpe.EtaExpand(tp.typeParamSymbols)
  tree.withType(tp1)
  }
- if ((ctx.mode is Mode.Pattern) || tree1.tpe <:< pt) tree1
+ if (ctx.mode.is(Mode.Pattern) || ctx.mode.is(Mode.QuotedPattern) || tree1.tpe <:< pt) tree1
  else err.typeMismatch(tree1, pt)
  }
 

tests/neg/i7264d.scala

@@ -0,0 +1,7 @@
+import scala.quoted._
+class Foo {
+ def f[T2: Type](e: Expr[T2])(given QuoteContext) = e match {
+ case '{ $x: *:[Int, Any] } => // error: Type argument Any does not conform to upper bound Tuple
+
+ }
+}

tests/pos/i7264.scala

@@ -0,0 +1,7 @@
+import scala.quoted._
+class Foo {
+ def f[T2](t: Type[T2])(given QuoteContext) = t match {
+ case '[ *:[Int, $t] ] =>
+ '[ *:[Int, $t] ]
+ }
+}

tests/pos/i7264b.scala

@@ -0,0 +1,7 @@
+import scala.quoted._
+class Foo {
+ def f[T2: Type](e: Expr[T2])(given QuoteContext) = e match {
+ case '{ $x: *:[Int, $t] } =>
+ '[ *:[Int, $t] ]
+ }
+}

tests/pos/i7264c.scala

@@ -0,0 +1,9 @@
+import scala.quoted._
+class Foo {
+ def f[T2: Type](e: Expr[T2])(given QuoteContext) = e match {
+ case '{ $x: $t0 } =>
+ t0 match
+ case '[ *:[Int, $t] ] =>
+ '[ *:[Int, $t] ]
+ }
+}