Do not crash when reading a Scala 2 macro definition.

It contains an annotation with a subtree that is an `IDENTtree` without prefix nor symbol, with the name `macro`. That is then `Apply`ed and `TypeApply`ed in ways that make no semantic sense. We define a special symbol in `Definitions`, which we attach to such fake identifiers.
scalacenter · Dec 14, 2023 · 12152c4 · 12152c4
1 parent f450e46
commit 12152c4
Show file tree

Hide file tree

Showing 4 changed files with 19 additions and 4 deletions.
diff --git a/tasty-query/shared/src/main/scala/tastyquery/Definitions.scala b/tasty-query/shared/src/main/scala/tastyquery/Definitions.scala
@@ -145,6 +145,15 @@ final class Definitions private[tastyquery] (ctx: Context, rootPackage: PackageS
       .checkCompleted()
   end scala2FakeOwner
 
+  private[tastyquery] val scala2MacroInfoFakeMethod: TermSymbol =
+    TermSymbol
+      .createNotDeclaration(nme.m_macro, scalaPackage)
+      .withFlags(Synthetic, None)
+      .withDeclaredType(NothingType)
+      .setAnnotations(Nil)
+      .checkCompleted()
+  end scala2MacroInfoFakeMethod
+
   private def createSpecialTypeAlias(
     name: TypeName,
     owner: DeclaringSymbol,

diff --git a/tasty-query/shared/src/main/scala/tastyquery/Names.scala b/tasty-query/shared/src/main/scala/tastyquery/Names.scala
@@ -63,6 +63,8 @@ object Names {
 
     val m_apply: SimpleName = termName("apply")
     val m_unapply: SimpleName = termName("unapply")
+
+    private[tastyquery] val m_macro: SimpleName = termName("macro")
   }
 
   object tpnme {

diff --git a/tasty-query/shared/src/main/scala/tastyquery/reader/ReaderContext.scala b/tasty-query/shared/src/main/scala/tastyquery/reader/ReaderContext.scala
@@ -45,6 +45,8 @@ private[reader] final class ReaderContext(underlying: Context):
 
   def scala2FakeOwner: TermSymbol = underlying.defn.scala2FakeOwner
 
+  def scala2MacroInfoFakeMethod: TermSymbol = underlying.defn.scala2MacroInfoFakeMethod
+
   def findPackageFromRootOrCreate(fullyQualifiedName: PackageFullName): PackageSymbol =
     underlying.findPackageFromRootOrCreate(fullyQualifiedName)
 

diff --git a/tasty-query/shared/src/main/scala/tastyquery/reader/pickles/PickleReader.scala b/tasty-query/shared/src/main/scala/tastyquery/reader/pickles/PickleReader.scala
@@ -1006,10 +1006,12 @@ private[pickles] class PickleReader {
         val designator = readMaybeExternalSymbolRef()
         val name = readTermNameRef()
         val tpe: TermReferenceType = designator match
-          case sym: TermSymbol             => sym.localRef
-          case sym: PackageSymbol          => sym.packageRef
-          case external: ExternalSymbolRef => external.toTermRef(NoPrefix)
-          case _                           => errorBadSignature(s"illegal $designator for IDENTtree (name '$name')")
+          case sym: TermSymbol                               => sym.localRef
+          case sym: PackageSymbol                            => sym.packageRef
+          case external: ExternalSymbolRef                   => external.toTermRef(NoPrefix)
+          case _: NoExternalSymbolRef if name == nme.m_macro => rctx.scala2MacroInfoFakeMethod.localRef
+          case _ =>
+            errorBadSignature(s"illegal $designator for IDENTtree (name '$name')")
         Ident(name)(tpe)(pos)
 
       case LITERALtree =>