Merge pull request #9975 from dotty-staging/fix-#9972

Fix #9972: Add missing span on implicit search failures

Author: odersky

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

@@ -409,13 +409,13 @@ object Implicits:
   }
 
   object SearchFailure {
-    def apply(tpe: SearchFailureType)(using Context): SearchFailure = {
+    def apply(tpe: SearchFailureType, span: Span)(using Context): SearchFailure = {
       val id = tpe match
         case tpe: AmbiguousImplicits =>
           untpd.SearchFailureIdent(nme.AMBIGUOUS, s"/* ambiguous: ${tpe.explanation} */")
         case _ =>
           untpd.SearchFailureIdent(nme.MISSING, "/* missing */")
-      SearchFailure(id.withTypeUnchecked(tpe))
+      SearchFailure(id.withTypeUnchecked(tpe).withSpan(span))
     }
   }
 
@@ -483,7 +483,7 @@ object Implicits:
   @sharable object NoMatchingImplicits extends NoMatchingImplicits(NoType, EmptyTree, OrderingConstraint.empty)
 
   @sharable val NoMatchingImplicitsFailure: SearchFailure =
-    SearchFailure(NoMatchingImplicits)(using NoContext)
+    SearchFailure(NoMatchingImplicits, NoSpan)(using NoContext)
 
   /** An ambiguous implicits failure */
   class AmbiguousImplicits(val alt1: SearchSuccess, val alt2: SearchSuccess, val expectedType: Type, val argument: Tree) extends SearchFailureType {
@@ -1022,7 +1022,7 @@ trait Implicits:
               }
             else result
           case NoMatchingImplicitsFailure =>
-            SearchFailure(new NoMatchingImplicits(pt, argument, ctx.typerState.constraint))
+            SearchFailure(new NoMatchingImplicits(pt, argument, ctx.typerState.constraint), span)
           case _ =>
             result0
         }
@@ -1123,7 +1123,7 @@ trait Implicits:
       */
     def tryImplicit(cand: Candidate, contextual: Boolean): SearchResult =
       if checkDivergence(cand) then
-        SearchFailure(new DivergingImplicit(cand.ref, wideProto, argument))
+        SearchFailure(new DivergingImplicit(cand.ref, wideProto, argument), span)
       else {
         val history = ctx.searchHistory.nest(cand, pt)
         val result =
@@ -1174,7 +1174,7 @@ trait Implicits:
 
           if diff < 0 then alt2
           else if diff > 0 then alt1
-          else SearchFailure(new AmbiguousImplicits(alt1, alt2, pt, argument))
+          else SearchFailure(new AmbiguousImplicits(alt1, alt2, pt, argument), span)
         case _: SearchFailure => alt2
 
       /** Try to find a best matching implicit term among all the candidates in `pending`.

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

@@ -132,7 +132,7 @@ object ProtoTypes {
 
     // equals comes from case class; no need to redefine
   end IgnoredProto
-  
+
   final class CachedIgnoredProto(ignored: Type) extends IgnoredProto(ignored)
 
   object IgnoredProto:

tests/neg-macros/i9972/Macro_1.scala

@@ -0,0 +1,7 @@
+package notmacro
+
+import scala.util.Not
+
+object Main extends App {
+  summon[Not[T[Int]]] // error
+}

tests/neg-macros/i9972/Test_2.scala

@@ -0,0 +1,12 @@
+package notmacro
+
+import scala.quoted._
+
+case class T[A <: AnyKind](s: String)
+
+object T {
+  implicit inline def derived[A <: AnyKind]: T[A] = ${ reprImpl[A] }
+
+  def reprImpl[A <: AnyKind](using t: Type[A])(using ctx: QuoteContext): Expr[T[A]] =
+    '{ T[A]("") }
+}

tests/neg-macros/i9972b/Macro_1.scala

@@ -0,0 +1,3 @@
+
+def test: Unit =
+  summon[scala.util.Not[T[Int]]] // error

tests/neg-macros/i9972b/Test_2.scala

@@ -0,0 +1,5 @@
+
+class T[A]
+
+object T:
+  implicit inline def derived[A]: T[A] = new T[A]