SI-7556 Fix runtime reflection involving ScalaLongSignature

Scala type information is stored in classfiles in encoded in a String in the ScalaSignature annotation. When it is too big for a single String, it is split into an array of Strings in a different annotation, ScalaLongSignature. The enclosed test, with a class containing 3000 methods, uses the latter. It exposes a bug in the way runtime reflection decodes that data. It must concatentate and *then* decode, rather that the other way around.
scala · Jun 5, 2013 · 28c5f730820dd76d85c2f6f81bf60aae03aabe41 · 28c5f73
1 parent 681f207
commit 28c5f730820dd76d85c2f6f81bf60aae03aabe41
Unified Split
Showing with 3,019 additions and 9 deletions.
+4 −9 src/reflect/scala/reflect/runtime/JavaMirrors.scala
+2 −0 test/files/run/t7556.check
+11 −0 test/files/run/t7556/Test_2.scala
+3,002 −0 test/files/run/t7556/mega-class_1.scala
diff --git a/src/reflect/scala/reflect/runtime/JavaMirrors.scala b/src/reflect/scala/reflect/runtime/JavaMirrors.scala
@@ -567,15 +567,10 @@ private[reflect] trait JavaMirrors extends internal.SymbolTable with api.JavaUni
 loadBytes[Array[String]]("scala.reflect.ScalaLongSignature") match {
 case Some(slsig) =>
 info(s"unpickling Scala $clazz and $module with long Scala signature")
-
-val byteSegments = slsig map (_.getBytes)
-
-val lens = byteSegments map ByteCodecs.decode
-
-val bytes = Array.ofDim[Byte](lens.sum)
-
-var len = 0
-
-for ((bs, l) <- byteSegments zip lens) {
-
-bs.copyToArray(bytes, len, l)
-
-len += l
-
-}
-
-unpickler.unpickle(bytes, 0, clazz, module, jclazz.getName)
+
+val encoded = slsig flatMap (_.getBytes)
+
+val len = ByteCodecs.decode(encoded)
+
+val decoded = encoded.take(len)
+
+unpickler.unpickle(decoded, 0, clazz, module, jclazz.getName)
 case None =>
 // class does not have a Scala signature; it's a Java class
 info("translating reflection info for Java " + jclazz) //debug

diff --git a/test/files/run/t7556.check b/test/files/run/t7556.check
@@ -0,0 +1,2 @@
+
+class annotations: List(scala.reflect.ScalaLongSignature)
+
+3001 decls via runtime reflection
diff --git a/test/files/run/t7556/Test_2.scala b/test/files/run/t7556/Test_2.scala
@@ -0,0 +1,11 @@
+
+import scala.reflect.runtime.universe._
+
+
+
+object Test {
+
+def main(args: Array[String]) {
+
+val mc = new MegaClass
+
+val anns = mc.getClass.getAnnotations.map(_.annotationType.getName).toList.sorted
+
+println(s"class annotations: $anns")
+
+val N = typeTag[MegaClass].tpe.declarations.size // was: error reading Scala signature of MegaClass: 65935
+
+println(s"$N decls via runtime reflection")
+
+}
+
+}