Merge pull request #410 from sjrd/missing-annotations

Fix #402: Recover from annotations that are missing on the classpath.

Author: sjrd

tasty-query/shared/src/main/scala/tastyquery/Annotations.scala

@@ -13,6 +13,7 @@ import tastyquery.Types.*
 object Annotations:
   final class Annotation(val tree: TermTree):
     private var mySymbol: ClassSymbol | Null = null
+    private var mySafeSymbol: Option[ClassSymbol] | Null = null
     private var myArguments: List[TermTree] | Null = null
 
     /** The annotation class symbol. */
@@ -22,9 +23,27 @@ object Annotations:
       else
         val computed = computeAnnotSymbol(tree)
         mySymbol = computed
+        mySafeSymbol = Some(computed)
         computed
     end symbol
 
+    /** Tests whether the annotation has the given class symbol.
+      *
+      * If the class of this annotation cannot be successfully resolved, returns `false`.
+      */
+    private[tastyquery] def safeHasSymbol(cls: ClassSymbol)(using Context): Boolean =
+      val safeSymbol =
+        val local = mySafeSymbol
+        if local != null then local
+        else
+          val local = computeSafeAnnotSymbol(tree)
+          local.foreach(mySymbol = _)
+          mySafeSymbol = local
+          local
+
+      safeSymbol.contains(cls)
+    end safeHasSymbol
+
     /** The symbol of the constructor used in the annotation.
       *
       * This operation is not supported for annotations read from Java or Scala 2.
@@ -138,6 +157,14 @@ object Annotations:
     }
   end computeAnnotSymbol
 
+  private def computeSafeAnnotSymbol(tree: TermTree)(using Context): Option[ClassSymbol] =
+    // This is not a very efficient way to deal with this, but I don't really see a good solution
+    try Some(computeAnnotSymbol(tree))
+    catch
+      case _: MemberNotFoundException =>
+        None
+  end computeSafeAnnotSymbol
+
   private def findNewAnnotTypeTree(tree: TermTree): TypeTree =
     def invalid(): Nothing =
       throw InvalidProgramStructureException(s"Cannot find annotation class in $tree")

tasty-query/shared/src/main/scala/tastyquery/Symbols.scala

@@ -199,13 +199,13 @@ object Symbols {
     final def asPackage: PackageSymbol = this.asInstanceOf[PackageSymbol]
 
     final def hasAnnotation(annotClass: ClassSymbol)(using Context): Boolean =
-      annotations.exists(_.symbol == annotClass)
+      annotations.exists(_.safeHasSymbol(annotClass))
 
     final def getAnnotations(annotClass: ClassSymbol)(using Context): List[Annotation] =
-      annotations.filter(_.symbol == annotClass)
+      annotations.filter(_.safeHasSymbol(annotClass))
 
     final def getAnnotation(annotClass: ClassSymbol)(using Context): Option[Annotation] =
-      annotations.find(_.symbol == annotClass)
+      annotations.find(_.safeHasSymbol(annotClass))
 
     override def toString: String = {
       val ownerPrefix = owner match

test-sources/src/main/scala/simple_trees/MissingAnnotations.scala

@@ -0,0 +1,15 @@
+package simple_trees
+
+import javax.annotation.processing.SupportedAnnotationTypes
+
+class MissingAnnotations:
+  @SupportedAnnotationTypes(Array("foo.bar"))
+  def foo(): String = "hello"
+end MissingAnnotations
+
+object MissingAnnotationsTest:
+  def test(): Unit =
+    // This used to fail to resolve under JDK 11+, because the annotation is not available in java.base
+    new MissingAnnotations().foo()
+  end test
+end MissingAnnotationsTest