Fix #10127: Don't try to get tags after error

The tags may be unavailablle due to the error.

Author: nicolasstucki

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

@@ -140,8 +140,11 @@ class PCPCheckAndHeal(@constructorOnly ictx: Context) extends TreeMapWithStages(
 
   protected def transformSpliceType(body: Tree, splice: Select)(using Context): Tree = {
     val body1 = transform(body)(using spliceContext)
-    val tagRef = getQuoteTypeTags.getTagRef(splice.qualifier.tpe.asInstanceOf[TermRef])
-    ref(tagRef).withSpan(splice.span)
+    if ctx.reporter.hasErrors then
+      splice
+    else
+      val tagRef = getQuoteTypeTags.getTagRef(splice.qualifier.tpe.asInstanceOf[TermRef])
+      ref(tagRef).withSpan(splice.span)
   }
 
   /** Check that annotations do not contain quotes and and that splices are valid */

tests/neg-macros/i10127-a.scala

@@ -0,0 +1,8 @@
+import scala.quoted._
+
+object T {
+  def impl[A](using t: Type[A])(using Quotes): Expr[Unit] = {
+    Expr.summon[t.Underlying] // error
+    '{}
+  }
+}

tests/neg-macros/i10127-b.scala

@@ -0,0 +1,10 @@
+import scala.quoted._
+
+case class T(x: Type[_ <: Any])
+
+object T {
+  def impl[A](t: T)(using ctx: Quotes): Expr[Unit] = {
+    Expr.summon[t.x.Underlying] // error // error
+    '{}
+  }
+}

tests/pos-macros/i10127.scala

@@ -0,0 +1,8 @@
+import scala.quoted._
+
+object T {
+  def impl[A](using Type[A])(using Quotes): Expr[Unit] = {
+    Expr.summon[A]
+    '{}
+  }
+}