Merge pull request #14800 from dotty-staging/fix-14788

Handle this prefix in classes (in quote patterns)

Author: smarter

compiler/src/scala/quoted/runtime/impl/QuoteMatcher.scala

@@ -245,11 +245,12 @@ object QuoteMatcher {
                   ref match
                     case Select(qual1, _) => qual1 =?= qual2
                     case ref: Ident =>
-                      ref.tpe match
-                        case TermRef(qual: TermRef, _) => tpd.ref(qual) =?= qual2
-                        case TermRef(qual: ThisType, _) if qual.classSymbol.is(Module, butNot = Package) =>
-                          tpd.ref(qual.classSymbol.companionModule) =?= qual2
-                        case _ => matched
+                      if qual2.existsSubTree(_.symbol == defn.QuotedRuntimePatterns_patternHole) then
+                        // Prefix has a hole, so we need to match the prefix to extract the value of the hole
+                        tpd.desugarIdentPrefix(ref) =?= qual2
+                      else
+                        matched
+
                 /* Match reference */
                 case _: Ident if symbolMatch(scrutinee, pattern) => matched
                 /* Match type */

tests/run-custom-args/tasty-inspector/i14788.scala

@@ -0,0 +1,55 @@
+
+import scala.quoted.*
+import scala.tasty.inspector.Inspector
+import scala.tasty.inspector.Tasty
+import scala.tasty.inspector.TastyInspector
+import scala.reflect.ClassTag
+
+import scala.quoted.*
+import scala.tasty.inspector.*
+
+@main def Test: Unit = {
+  // Artefact of the current test infrastructure
+  // TODO improve infrastructure to avoid needing this code on each test
+  val classpath = dotty.tools.dotc.util.ClasspathFromClassloader(this.getClass.getClassLoader).split(java.io.File.pathSeparator).find(_.contains("runWithCompiler")).get
+  val allTastyFiles = dotty.tools.io.Path(classpath).walkFilter(_.extension == "tasty").map(_.toString).toList
+  val tastyFiles = allTastyFiles.filter(_.contains("MySeq"))
+
+  TastyInspector.inspectTastyFiles(tastyFiles)(new MyInspector)
+}
+
+class MySeq(override val length: Int) extends collection.Seq[String] {
+  def foo: Int = length // error
+
+  def apply(v1: Int): String = ???
+  def iterator: Iterator[String] = ???
+}
+
+class MyInspector extends Inspector {
+  def inspect(using Quotes)(tastys: List[Tasty[quotes.type]]): Unit = {
+    import quotes.reflect.*
+    val traverser = new TreeTraverser {
+      override def traverseTree(tree: Tree)(owner: Symbol): Unit = {
+        if (tree.isExpr) {
+          try {
+            tree.asExpr match {
+              case '{ ($x: collection.Seq[t]).length } =>
+                super.traverseTree(tree)(owner)
+              case _ =>
+                super.traverseTree(tree)(owner)
+            }
+          } catch {
+            case e =>
+              report.error(s"unexpected error ${e}", tree.pos)
+              throw e
+          }
+        } else {
+          super.traverseTree(tree)(owner)
+        }
+      }
+    }
+    tastys.foreach{ tasty =>
+      traverser.traverseTree(tasty.ast)(tasty.ast.symbol)
+    }
+  }
+}