Merge pull request scalacenter#389 from sjrd/java-annotations

Read Java annotations.

Author: bishabosha

build.sbt

@@ -68,6 +68,7 @@ lazy val testSources = crossProject(JSPlatform, JVMPlatform)
   .settings(
     publish / skip := true,
     scalacOptions += "-Xfatal-warnings",
+    javacOptions += "-parameters",
   )
 
 lazy val tastyQuery =

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

@@ -27,7 +27,7 @@ object Annotations:
 
     /** The symbol of the constructor used in the annotation.
       *
-      * This operation is not supported for annotations read from Scala 2.
+      * This operation is not supported for annotations read from Java or Scala 2.
       * It will throw an `UnsupportedOperationException`.
       */
     def annotConstructor(using Context): TermSymbol =
@@ -111,6 +111,24 @@ object Annotations:
 
       new Annotation(tree)
     end apply
+
+    private[tastyquery] def fromAnnotTypeAndArgs(annotationType: Type, args: List[TermTree]): Annotation =
+      val pos = SourcePosition.NoPosition
+
+      /* Create a TermTree for the annotation that is "good enough" for the main
+       * methods of `Annotation` to work, notably `symbol` and `arguments`.
+       * We have to cheat for the constructor, as we do not have its Signature.
+       * Instead we use an unsigned `nme.Constructor`. This is invalid and will
+       * cause `Annotation.annotConstructor` to fail, but we do not really have
+       * a choice.
+       */
+      val annotationTree: TermTree =
+        val newNode = New(TypeWrapper(annotationType)(pos))(pos)
+        val selectCtorNode = Select(newNode, nme.Constructor)(None)(pos) // cheating here
+        Apply(selectCtorNode, args)(pos)
+
+      Annotation(annotationTree)
+    end fromAnnotTypeAndArgs
   end Annotation
 
   private def computeAnnotSymbol(tree: TermTree)(using Context): ClassSymbol =
@@ -140,13 +158,15 @@ object Annotations:
     def invalid(): Nothing =
       throw InvalidProgramStructureException(s"Cannot find annotation constructor in $tree")
 
-    def unsupportedScala2(): Nothing =
-      throw UnsupportedOperationException(s"Cannot compute the annotation constructor of a Scala 2 annotation: $tree")
+    def unsupported(): Nothing =
+      throw UnsupportedOperationException(
+        s"Cannot compute the annotation constructor of a Java or Scala 2 annotation: $tree"
+      )
 
     @tailrec
     def loop(tree: TermTree): TermSymbol = tree match
       case Apply(fun, _)                 => loop(fun)
-      case tree @ Select(New(tpt), name) => if name == nme.Constructor then unsupportedScala2() else tree.symbol.asTerm
+      case tree @ Select(New(tpt), name) => if name == nme.Constructor then unsupported() else tree.symbol.asTerm
       case TypeApply(fun, _)             => loop(fun)
       case Block(_, expr)                => loop(expr)
       case _                             => invalid()

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

@@ -166,6 +166,13 @@ object Constants {
 
     def stringValue: String = if tag == NullTag then "null" else value.toString
 
+    /** The class type value of a `classOf` constant.
+      *
+      * This must be a "possibly parametrized class type" according to the
+      * specification of the language. If the class is polymorphic, it may be
+      * applied (making it a proper type) or not (in which case it is not a
+      * proper type).
+      */
     def typeValue: Type = value.asInstanceOf[Type]
 
     override def hashCode: Int = {

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

@@ -118,6 +118,7 @@ final class Definitions private[tastyquery] (ctx: Context, rootPackage: PackageS
       .withDeclaredType(tpe)
       .setAnnotations(Nil)
       .autoFillParamSymss()
+    sym.paramSymss.foreach(_.merge.foreach(_.setAnnotations(Nil)))
     sym.checkCompleted()
     sym
   end createSpecialMethod
@@ -347,6 +348,7 @@ final class Definitions private[tastyquery] (ctx: Context, rootPackage: PackageS
     )
     applyMethod.autoFillParamSymss()
     applyMethod.setAnnotations(Nil)
+    applyMethod.paramSymss.foreach(_.merge.foreach(_.setAnnotations(Nil)))
     applyMethod.checkCompleted()
 
     cls.checkCompleted()

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

@@ -489,7 +489,6 @@ object Symbols {
             .createNotDeclaration(name, this)
             .withFlags(EmptyFlagSet, privateWithin = None)
             .withDeclaredType(paramType)
-            .setAnnotations(Nil)
         }
         Left(paramSyms) :: autoComputeParamSymss(tpe.resultType)
 
@@ -498,7 +497,6 @@ object Symbols {
           LocalTypeParamSymbol
             .create(name, this)
             .withFlags(EmptyFlagSet, privateWithin = None)
-            .setAnnotations(Nil)
         }
         val paramSymRefs = paramSyms.map(_.localRef)
         def subst(t: TypeOrMethodic): t.ThisTypeMappableType =

tasty-query/shared/src/main/scala/tastyquery/reader/classfiles/ClassfileParser.scala

@@ -1,23 +1,28 @@
 package tastyquery.reader.classfiles
 
+import scala.annotation.switch
+
 import scala.collection.mutable
 
-import tastyquery.Annotations.Annotation as TQAnnotation
+import tastyquery.Annotations.*
 import tastyquery.Classpaths.*
 import tastyquery.Contexts.*
+import tastyquery.Constants.*
 import tastyquery.Exceptions.*
 import tastyquery.Flags
 import tastyquery.Flags.*
 import tastyquery.Names.*
 import tastyquery.SourceLanguage
+import tastyquery.SourcePosition
 import tastyquery.Symbols.*
+import tastyquery.Trees.*
 import tastyquery.Types.*
 
 import tastyquery.reader.ReaderContext
 import tastyquery.reader.ReaderContext.rctx
 import tastyquery.reader.pickles.{Unpickler, PickleReader}
 
-import ClassfileReader.*
+import ClassfileReader.{Annotation as CFAnnotation, *}
 import ClassfileReader.Access.AccessFlags
 import Constants.*
 
@@ -63,6 +68,8 @@ private[reader] object ClassfileParser {
     def resolve(binaryName: SimpleName)(using ReaderContext, InnerClasses): TypeRef =
       lookup(binaryName, isStatic = false).asTypeRef
 
+    def resolveStatic(binaryName: SimpleName)(using ReaderContext, InnerClasses): TermRef =
+      lookup(binaryName, isStatic = true).asTermRef
   end Resolver
 
   /** The inner classes local to a class file */
@@ -127,10 +134,10 @@ private[reader] object ClassfileParser {
 
     val sigBytes = scalaSigAnnotation.tpe match {
       case annot.ScalaSignature =>
-        val bytesArg = scalaSigAnnotation.values.head.asInstanceOf[AnnotationValue.Const]
+        val bytesArg = scalaSigAnnotation.values.head._2.asInstanceOf[AnnotationValue.Const]
         pool.sigbytes(bytesArg.valueIdx)
       case annot.ScalaLongSignature =>
-        val bytesArrArg = scalaSigAnnotation.values.head.asInstanceOf[AnnotationValue.Arr]
+        val bytesArrArg = scalaSigAnnotation.values.head._2.asInstanceOf[AnnotationValue.Arr]
         val idxs = bytesArrArg.values.map(_.asInstanceOf[AnnotationValue.Const].valueIdx)
         pool.sigbytes(idxs)
     }
@@ -200,15 +207,31 @@ private[reader] object ClassfileParser {
       else false
     end isSignaturePolymorphic
 
-    def createMember(name: SimpleName, isMethod: Boolean, javaFlags: AccessFlags, memberSig: MemberSig): TermSymbol =
+    def createMember(
+      name: SimpleName,
+      isMethod: Boolean,
+      javaFlags: AccessFlags,
+      descriptor: String,
+      attributes: Map[SimpleName, Forked[DataStream]]
+    ): TermSymbol =
       // Select the right owner and create the symbol
       val owner = if javaFlags.isStatic then moduleClass else cls
       val sym = TermSymbol.create(name, owner)
       allRegisteredSymbols += sym
 
+      // Read parameter names
+      val methodParamNames =
+        if isMethod then readMethodParameters(attributes).map(_._1)
+        else Nil
+
+      // Find the signature, or fall back to the descriptor
+      val memberSig = attributes.get(attr.Signature) match
+        case Some(stream) => stream.use(ClassfileReader.readSignature)
+        case None         => descriptor
+
       // Parse the signature into a declared type for the symbol
       val declaredType =
-        val parsedType = JavaSignatures.parseSignature(sym, isMethod, memberSig, allRegisteredSymbols)
+        val parsedType = JavaSignatures.parseSignature(sym, isMethod, methodParamNames, memberSig, allRegisteredSymbols)
         val adaptedType =
           if isMethod && sym.name == nme.Constructor then cls.makePolyConstructorType(parsedType)
           else if isMethod && javaFlags.isVarargsIfMethod then patchForVarargs(sym, parsedType)
@@ -226,23 +249,46 @@ private[reader] object ClassfileParser {
       end flags
       sym.withFlags(flags, privateWithin(javaFlags))
 
-      // Auto fill the param symbols from the declared type
-      sym.autoFillParamSymss()
-
-      sym.setAnnotations(Nil) // TODO Read Java annotations on fields and methods
+      // Read and fill annotations
+      val annots = readAnnotations(sym, attributes)
+      sym.setAnnotations(annots)
+
+      // Handle parameters
+      if isMethod then
+        // Auto fill the param symbols from the declared type
+        sym.autoFillParamSymss()
+
+        val termParamAnnots = readTermParamAnnotations(attributes)
+        if termParamAnnots.isEmpty then
+          // fast path
+          sym.paramSymss.foreach(_.merge.foreach(_.setAnnotations(Nil)))
+        else
+          val termParamAnnotsIter = termParamAnnots.iterator
+
+          for paramSyms <- sym.paramSymss do
+            paramSyms match
+              case Left(termParamSyms) =>
+                for termParamSym <- termParamSyms do
+                  val annots = if termParamAnnotsIter.hasNext then termParamAnnotsIter.next() else Nil
+                  termParamSym.setAnnotations(annots)
+              case Right(typeParamSyms) =>
+                // TODO Maybe one day we also read type annotations
+                typeParamSyms.foreach(_.setAnnotations(Nil))
+        end if
+      end if
 
       sym
     end createMember
 
     def loadMembers(): Unit =
       structure.fields.use {
-        ClassfileReader.readFields { (name, sigOrDesc, javaFlags) =>
-          createMember(name, isMethod = false, javaFlags, sigOrDesc)
+        ClassfileReader.readMembers { (javaFlags, name, descriptor, attributes) =>
+          createMember(name, isMethod = false, javaFlags, descriptor, attributes)
         }
       }
       structure.methods.use {
-        ClassfileReader.readMethods { (name, sigOrDesc, javaFlags) =>
-          createMember(name, isMethod = true, javaFlags, sigOrDesc)
+        ClassfileReader.readMembers { (javaFlags, name, descriptor, attributes) =>
+          createMember(name, isMethod = true, javaFlags, descriptor, attributes)
         }
       }
     end loadMembers
@@ -254,7 +300,9 @@ private[reader] object ClassfileParser {
       val parents = attributes.get(attr.Signature) match
         case Some(stream) =>
           val sig = stream.use(ClassfileReader.readSignature)
-          JavaSignatures.parseSignature(cls, isMethod = false, sig, allRegisteredSymbols).requireType match
+          val parsedSig =
+            JavaSignatures.parseSignature(cls, isMethod = false, methodParameterNames = Nil, sig, allRegisteredSymbols)
+          parsedSig.requireType match
             case mix: AndType => mix.parts
             case sup          => sup :: Nil
         case None =>
@@ -273,7 +321,6 @@ private[reader] object ClassfileParser {
 
     cls.withGivenSelfType(None)
     cls.withFlags(clsFlags, clsPrivateWithin)
-    cls.setAnnotations(Nil) // TODO Read Java annotations on classes
     initParents()
 
     // Intercept special classes to create their magic methods
@@ -284,6 +331,9 @@ private[reader] object ClassfileParser {
 
     loadMembers()
 
+    val annotations = readAnnotations(cls, attributes)
+    cls.setAnnotations(annotations)
+
     for sym <- allRegisteredSymbols do
       sym.checkCompleted()
       assert(sym.sourceLanguage == SourceLanguage.Java, s"$sym of ${sym.getClass()}")
@@ -324,6 +374,115 @@ private[reader] object ClassfileParser {
           None
   end ArrayTypeExtractor
 
+  private def readMethodParameters(attributes: AttributeMap)(
+    using ConstantPool
+  ): List[(UnsignedTermName, AccessFlags)] =
+    attributes.get(attr.MethodParameters) match
+      case Some(stream) => stream.use(ClassfileReader.readMethodParameters())
+      case None         => Nil
+  end readMethodParameters
+
+  private def readAnnotations(
+    sym: TermOrTypeSymbol,
+    attributes: AttributeMap
+  )(using ConstantPool, ReaderContext, InnerClasses, Resolver): List[Annotation] =
+    readAnnotations(sym, attributes.get(attr.RuntimeVisibleAnnotations))
+      ::: readAnnotations(sym, attributes.get(attr.RuntimeInvisibleAnnotations))
+  end readAnnotations
+
+  private def readAnnotations(
+    sym: TermOrTypeSymbol,
+    annotationsStream: Option[Forked[DataStream]]
+  )(using ConstantPool, ReaderContext, InnerClasses, Resolver): List[Annotation] =
+    annotationsStream.fold(Nil)(readAnnotations(sym, _))
+  end readAnnotations
+
+  private def readAnnotations(
+    sym: TermOrTypeSymbol,
+    annotationsStream: Forked[DataStream]
+  )(using ConstantPool, ReaderContext, InnerClasses, Resolver): List[Annotation] =
+    val classfileAnnots = annotationsStream.use(ClassfileReader.readAllAnnotations())
+    classfileAnnots.map(classfileAnnotToAnnot(_))
+
+  private def readTermParamAnnotations(
+    attributes: AttributeMap
+  )(using ConstantPool, ReaderContext, InnerClasses, Resolver): List[List[Annotation]] =
+    val runtimeVisible = attributes.get(attr.RuntimeVisibleParameterAnnotations) match
+      case None         => Nil
+      case Some(stream) => stream.use(ClassfileReader.readAllParameterAnnotations())
+
+    val runtimeInvisible = attributes.get(attr.RuntimeInvisibleParameterAnnotations) match
+      case None         => Nil
+      case Some(stream) => stream.use(ClassfileReader.readAllParameterAnnotations())
+
+    if runtimeVisible.isEmpty && runtimeInvisible.isEmpty then
+      // fast path
+      Nil
+    else
+      for (rtVisible, rtInvisible) <- runtimeVisible.zipAll(runtimeInvisible, Nil, Nil)
+      yield (rtVisible ::: rtInvisible).map(classfileAnnotToAnnot(_))
+  end readTermParamAnnotations
+
+  private def classfileAnnotToAnnot(
+    classfileAnnot: CFAnnotation
+  )(using ConstantPool, ReaderContext, InnerClasses, Resolver): Annotation =
+    val annotationType = JavaSignatures.parseFieldDescriptor(classfileAnnot.tpe.name)
+
+    val args: List[TermTree] =
+      for (name, value) <- classfileAnnot.values.toList yield
+        val valueTree = annotationValueToTree(value)
+        NamedArg(name, valueTree)(SourcePosition.NoPosition)
+
+    Annotation.fromAnnotTypeAndArgs(annotationType, args)
+  end classfileAnnotToAnnot
+
+  private def annotationValueToTree(
+    value: AnnotationValue
+  )(using ConstantPool, ReaderContext, InnerClasses, Resolver): TermTree =
+    import AnnotationValue.Tags
+
+    val pool = summon[ConstantPool]
+    val pos = SourcePosition.NoPosition
+
+    value match
+      case AnnotationValue.Const(tag, valueIdx) =>
+        val constant = (tag: @switch) match
+          case Tags.Byte    => Constant(pool.integer(valueIdx).toByte)
+          case Tags.Char    => Constant(pool.integer(valueIdx).toChar)
+          case Tags.Double  => Constant(pool.double(valueIdx))
+          case Tags.Float   => Constant(pool.float(valueIdx))
+          case Tags.Int     => Constant(pool.integer(valueIdx))
+          case Tags.Long    => Constant(pool.long(valueIdx))
+          case Tags.Short   => Constant(pool.integer(valueIdx).toShort)
+          case Tags.Boolean => Constant(pool.integer(valueIdx) != 0)
+          case Tags.String  => Constant(pool.utf8(valueIdx).name)
+        Literal(constant)(pos)
+
+      case AnnotationValue.EnumConst(descriptor, constName) =>
+        /* JVMS says that it can be any field descriptor,
+         * but I don't see what we would do with a base type or array type.
+         */
+        val binaryName = descriptor.name match
+          case s"L$binaryName;" => binaryName
+          case other            => throw ClassfileFormatException(s"unexpected non-class field descriptor: $other")
+        val enumClassStaticRef = resolver.resolveStatic(termName(binaryName))
+        val constRef = TermRef(enumClassStaticRef, constName)
+        Ident(constName)(constRef)(pos)
+
+      case AnnotationValue.ClassConst(descriptor) =>
+        val classType = JavaSignatures.parseReturnDescriptor(descriptor.name)
+        Literal(Constant(classType))(pos)
+
+      case AnnotationValue.NestedAnnotation(annotation) =>
+        val nestedAnnot = classfileAnnotToAnnot(annotation)
+        nestedAnnot.tree
+
+      case AnnotationValue.Arr(values) =>
+        val valueTrees = values.map(annotationValueToTree(_)).toList
+        val elemType = rctx.AnyType // TODO This will not be type-correct
+        SeqLiteral(valueTrees, TypeWrapper(elemType)(pos))(pos)
+  end annotationValueToTree
+
   def detectClassKind(structure: Structure): ClassKind =
     import structure.given