Merge pull request scala#4486 from mpociecha/ticket/8679

SI-8679 Add support for ScalaLongSignature attribute in scalap

Author: lrytz

src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala

@@ -925,6 +925,7 @@ abstract class ClassfileParser {
       Some(ScalaSigBytes(pool.getBytes(entries.toList)))
     }
 
+    // TODO SI-9296 duplicated code, refactor
     /* Parse and return a single annotation.  If it is malformed,
      * return None.
      */

src/reflect/scala/reflect/runtime/JavaMirrors.scala

@@ -591,6 +591,7 @@ private[scala] trait JavaMirrors extends internal.SymbolTable with api.JavaUnive
       // don't use classOf[scala.reflect.ScalaSignature] here, because it will use getClass.getClassLoader, not mirror's classLoader
       // don't use asInstanceOf either because of the same reason (lol, I cannot believe I fell for it)
       // don't use structural types to simplify reflective invocations because of the same reason
+      // TODO SI-9296 duplicated code, refactor
       def loadAnnotation(name: String): Option[java.lang.annotation.Annotation] =
         tryJavaClass(name) flatMap { annotClass =>
           val anns = jclazz.getAnnotations

src/scalap/scala/tools/scalap/Main.scala

@@ -28,6 +28,7 @@ import scalax.rules.scalasig._
 class Main {
   val SCALA_SIG            = "ScalaSig"
   val SCALA_SIG_ANNOTATION = "Lscala/reflect/ScalaSignature;"
+  val SCALA_LONG_SIG_ANNOTATION = "Lscala/reflect/ScalaLongSignature;"
   val BYTES_VALUE          = "bytes"
 
   val versionMsg = "Scala classfile decoder %s -- %s\n".format(Properties.versionString, Properties.copyrightString)

src/scalap/scala/tools/scalap/scalax/rules/scalasig/ScalaSig.scala

@@ -14,20 +14,32 @@ package scalasig
 import scala.language.postfixOps
 import scala.language.implicitConversions
 
-import ClassFileParser.{ ConstValueIndex, Annotation }
+import ClassFileParser._
 import scala.reflect.internal.pickling.ByteCodecs
 
 object ScalaSigParser {
-  import Main.{ SCALA_SIG, SCALA_SIG_ANNOTATION, BYTES_VALUE }
+  import Main.{ BYTES_VALUE, SCALA_LONG_SIG_ANNOTATION, SCALA_SIG, SCALA_SIG_ANNOTATION }
 
+  // TODO SI-9296 duplicated code, refactor
   def scalaSigFromAnnotation(classFile: ClassFile): Option[ScalaSig] = {
     import classFile._
 
-    classFile.annotation(SCALA_SIG_ANNOTATION) map {
+    def getBytes(bytesElem: AnnotationElement): Array[Byte] = bytesElem.elementValue match {
+      case ConstValueIndex(index) => bytesForIndex(index)
+      case ArrayValue(signatureParts) => mergedLongSignatureBytes(signatureParts)
+    }
+
+    def mergedLongSignatureBytes(signatureParts: Seq[ElementValue]): Array[Byte] = signatureParts.flatMap {
+      case ConstValueIndex(index) => bytesForIndex(index)
+    }(collection.breakOut)
+
+    def bytesForIndex(index: Int) = constantWrapped(index).asInstanceOf[StringBytesPair].bytes
+
+    classFile.annotation(SCALA_SIG_ANNOTATION)
+      .orElse(classFile.annotation(SCALA_LONG_SIG_ANNOTATION)).map {
       case Annotation(_, elements) =>
         val bytesElem = elements.find(elem => constant(elem.elementNameIndex) == BYTES_VALUE).get
-        val bytes = ((bytesElem.elementValue match {case ConstValueIndex(index) => constantWrapped(index)})
-                .asInstanceOf[StringBytesPair].bytes)
+        val bytes = getBytes(bytesElem)
         val length = ByteCodecs.decode(bytes)
 
         ScalaSigAttributeParsers.parse(ByteCode(bytes.take(length)))