Rewrite @ScalaSignature when shading

README.md

@@ -229,6 +229,13 @@ To see the verbose output for shading:
     logLevel in assembly := Level.Debug
 ```
 
+#### Scala libraries
+
+Scala classes contain an annotation which, among other things, contain all symbols referenced in that class. As of sbt-assembly XXX the rename rules
+will be applied to these annotations as well which makes it possible to compile or reflect against a shaded library.   
+
+This is currently limited to renaming packages. Renaming class names will not work and cause compiler errors when compiling against the shaded library.
+
 Excluding JARs and files
 ------------------------
 

build.sbt

@@ -14,7 +14,8 @@ lazy val root = (project in file(".")).
     scalacOptions := Seq("-deprecation", "-unchecked", "-Dscalac.patmat.analysisBudget=1024", "-Xfuture"),
     libraryDependencies ++= Seq(
       "org.scalactic" %% "scalactic" % "3.0.8",
-      "org.pantsbuild" % "jarjar" % "1.7.2"
+      "org.pantsbuild" % "jarjar" % "1.7.2",
+      "org.scalatest" %% "scalatest" % "3.1.1" % Test,
     ),
     crossSbtVersions := Seq("0.13.18", "1.2.8"), // https://github.com/sbt/sbt/issues/5049
     publishArtifact in (Compile, packageBin) := true,

src/main/scala/org/pantsbuild/jarjar/JJProcessor.scala

@@ -1,31 +1,99 @@
 package org.pantsbuild.jarjar
 
-import org.pantsbuild.jarjar.util.{EntryStruct, JarProcessor}
+import java.io.IOException
+
+import org.pantsbuild.jarjar.misplaced.MisplacedClassProcessorFactory
+import org.pantsbuild.jarjar.util.{EntryStruct, JarProcessor, JarProcessorChain, JarTransformerChain, RemappingClassTransformer, StandaloneJarProcessor}
 
 import scala.collection.JavaConverters._
+import scala.collection.mutable
+
+/**
+ * Creates a new JJProcessor, which automatically generates the standard zap, keep, remap, etc processors.
+ * This is a copy of the MainProcessor in JarJar with an added ScalaSigProcessor
+ *
+ * @param patterns               List of rules to parse.
+ * @param verbose                Whether to verbosely log information.
+ * @param skipManifest           If true, omits the manifest file from the processed jar.
+ * @param misplacedClassStrategy The strategy to use when processing class files that are in the
+ *                               wrong package (see MisplacedClassProcessorFactory.STRATEGY_* constants).
+ */
+class JJProcessor(val patterns: Seq[PatternElement], val verbose: Boolean, val skipManifest: Boolean, val misplacedClassStrategy: String) extends JarProcessor {
+
+  val zapList: Seq[Zap] = patterns.collect { case zap: Zap => zap }
+  val ruleList: Seq[Rule] = patterns.collect { case rule: Rule => rule }
+  val keepList: Seq[Keep] = patterns.collect { case keep: Keep => keep }
+  val renames: mutable.Map[String, String] = collection.mutable.HashMap[String, String]()
+
+  val kp: KeepProcessor = if (keepList.isEmpty) null else new KeepProcessor(keepList.asJava)
+
+  val pr = new PackageRemapper(ruleList.asJava, verbose)
 
-class JJProcessor(val proc: JarProcessor) {
+  val processors: mutable.ArrayBuffer[JarProcessor] = collection.mutable.ArrayBuffer[JarProcessor]()
+  if (skipManifest)
+    processors += ManifestProcessor.getInstance
+  if (kp != null)
+    processors += kp
 
-  def process(entry: EntryStruct): Boolean = proc.process(entry)
+  val misplacedClassProcessor: JarProcessor = MisplacedClassProcessorFactory.getInstance.getProcessorForName(misplacedClassStrategy)
+  processors += new ZapProcessor(zapList.asJava)
+  processors += misplacedClassProcessor
+  processors += new JarTransformerChain(Array[RemappingClassTransformer](new RemappingClassTransformer(pr)))
 
-  def getExcludes(): Set[String] = {
-    val field = proc.getClass().getDeclaredField("kp")
-    field.setAccessible(true)
-    val keepProcessor = field.get(proc)
+  val renamer: String => Option[String] = {
+    val wildcards = PatternElement.createWildcards(ruleList.asJava).asScala
 
-    if (keepProcessor == null) Set()
-    else {
-      val method = proc.getClass().getDeclaredMethod("getExcludes")
-      method.setAccessible(true)
-      method.invoke(proc).asInstanceOf[java.util.Set[String]].asScala.toSet
+    value: String => {
+      val result = wildcards.flatMap {
+        wc =>
+          val slashed = value.replace('.', '/') // The jarjar wildcards expect slashes instead of dots
+          // Hack to replace the package object name.
+          val renamed = Option(wc.replace(slashed)).orElse(Option(wc.replace(slashed + "/")).map(_.dropRight(1)))
+          renamed.map(_.replace('/', '.'))  // Unslash
+      }.headOption
+
+      result
     }
   }
 
-}
+  processors += new ScalaSigProcessor(renamer)
+  processors += new MethodSignatureProcessor(pr)
+  processors += new ResourceProcessor(pr)
+  val chain = new JarProcessorChain(processors.toArray)
 
-object JJProcessor {
+  @throws[IOException]
+  def strip(file: Nothing): Unit = {
+    if (kp != null) {
+      val excludes = getExcludes
+      if (excludes.nonEmpty) StandaloneJarProcessor.run(file, file, new ExcludeProcessor(excludes.asJava, verbose))
+    }
+  }
 
-  def apply(patterns: Seq[PatternElement], verbose: Boolean, skipManifest: Boolean): JJProcessor =
-    new JJProcessor(new MainProcessor(patterns.asJava, verbose, skipManifest))
+  /**
+   * Returns the <code>.class</code> files to delete. As well the root-parameter as the rename ones
+   * are taken in consideration, so that the concerned files are not listed in the result.
+   *
+   * @return the paths of the files in the jar-archive, including the <code>.class</code> suffix
+   */
+  def getExcludes: Set[String] = if (kp != null) kp.getExcludes.asScala.map { exclude =>
+      val name = exclude + ".class"
+      renames.getOrElse(name, name)
+    }.toSet else Set.empty
 
+  /**
+   *
+   * @param struct entry struct to process
+   * @return <code>true</code> if the entry is to include in the output jar
+   * @throws IOException
+   */
+  @throws[IOException]
+  def process(struct: EntryStruct): Boolean = {
+    val name = struct.name
+    val keepIt = chain.process(struct)
+    if (keepIt) if (!name.equals(struct.name)) {
+      if (kp != null) renames.put(name, struct.name)
+      if (verbose) System.err.println("Renamed " + name + " -> " + struct.name)
+    } else if (verbose) System.err.println("Removed " + name)
+    keepIt
+  }
 }

src/main/scala/org/pantsbuild/jarjar/ScalaSigProcessor.scala

@@ -0,0 +1,20 @@
+package org.pantsbuild.jarjar
+
+import org.objectweb.asm.{ClassReader, ClassWriter}
+import org.pantsbuild.jarjar.util.{EntryStruct, JarProcessor}
+import sbtassembly.scalasig.ScalaSigClassVisitor
+
+class ScalaSigProcessor(renamer: String => Option[String]) extends JarProcessor {
+  override def process(struct: EntryStruct): Boolean = {
+
+    if (!struct.name.endsWith(".class") || struct.skipTransform) true
+    else {
+      val classWriter = new ClassWriter(ClassWriter.COMPUTE_MAXS)
+      val reader = new ClassReader(struct.data)
+
+      reader.accept(new ScalaSigClassVisitor(classWriter, renamer), ClassReader.EXPAND_FRAMES)
+      struct.data = classWriter.toByteArray
+      true
+    }
+  }
+}

src/main/scala/sbtassembly/Shader.scala

@@ -2,9 +2,8 @@ package sbtassembly
 
 import java.io.File
 
-import org.pantsbuild.jarjar._
+import org.pantsbuild.jarjar.{JJProcessor, _}
 import org.pantsbuild.jarjar.util.EntryStruct
-
 import sbt._
 
 case class ShadeRule(shadePattern: ShadePattern, targets: Seq[ShadeTarget] = Seq()) {
@@ -83,7 +82,7 @@ private[sbtassembly] object Shader {
       case _ => Nil
     }}
 
-    val proc = JJProcessor(jjrules, verbose = level == Level.Debug, true)
+    val proc = new JJProcessor(jjrules, verbose = level == Level.Debug, true, null)
 
     /*
     jarjar MisplacedClassProcessor class transforms byte[] to a class using org.objectweb.asm.ClassReader.getClassName
@@ -104,7 +103,7 @@ private[sbtassembly] object Shader {
         IO.write(dir / entry.name, entry.data)
       }
     }
-    val excludes = proc.getExcludes()
+    val excludes = proc.getExcludes
     excludes.foreach(exclude => IO.delete(dir / exclude))
   }
-}
+}

src/main/scala/sbtassembly/scalasig/ByteArrayReader.scala

@@ -0,0 +1,22 @@
+package sbtassembly.scalasig
+
+// Utility class to read the content of a single table entry
+class ByteArrayReader(bytes: Array[Byte]) extends Nat.Reader {
+  private var readIndex = 0
+
+  /** Read a byte */
+  override def readByte(): Int = {
+    val x = bytes(readIndex).toInt
+    readIndex += 1
+    x
+  }
+
+  /** Reads a number of bytes into an array */
+  def readBytes(len: Int): Array[Byte] = {
+    val result = bytes.slice(readIndex, readIndex + len)
+    readIndex += len
+    result
+  }
+
+  def atEnd: Boolean = readIndex == bytes.length
+}

src/main/scala/sbtassembly/scalasig/EntryTable.scala

@@ -0,0 +1,150 @@
+package sbtassembly.scalasig
+
+import java.io.ByteArrayOutputStream
+
+import scala.collection.mutable
+import scala.reflect.internal.pickling.PickleFormat
+
+/**
+ * Mutable table of tagged entries
+ * @param majorVersion major table version
+ * @param minorVersion minor table version
+ * @param entries initial table entries
+ */
+class EntryTable(majorVersion: Int, minorVersion: Int, entries: mutable.Buffer[TaggedEntry]) {
+  // Mapping of known TermName or TypeNames to their index in the table.
+  private val nameIndices: mutable.Map[NameEntry, Int] = mutable.HashMap(
+    entries.zipWithIndex.collect {
+      case (entry: NameEntry, index) => (entry, index)
+    }:_*
+  )
+
+  /**
+   * Return the current table entries as an immutable seq.
+   * @return table entries
+   */
+  def toSeq: Seq[TaggedEntry] = entries.toVector
+
+  /**
+   * Rename term and type entries in this table according to the renamer function.
+   * A name or type is referred to by a Ref entry. The existing ref entries are reused to references to them will remain intact.
+   * Unused entries will not be removed from the table.
+   *
+   * @param renamer renames a fully qualified type or term name or return None if it does not match.
+   */
+  def renameEntries(renamer: String => Option[String]): Unit = {
+
+    entries.zipWithIndex.collect {
+      case (ref: RefEntry, index) =>
+        entries(ref.nameRef) match {
+          case nameEntry: NameEntry =>
+            for {
+              fqName <- resolveRef(ref)
+              renamed <- renamer(fqName)
+            } {
+              val parts = renamed.split('.')
+
+              val myOwner = parts.init.foldLeft(Option.empty[Int]) { (owner, part) =>
+                val nameIndex = getOrAppendNameEntry(NameEntry(PickleFormat.TERMname, part))
+                val nextOwner = appendEntry(RefEntry(PickleFormat.EXTMODCLASSref, nameIndex, owner))
+                Some(nextOwner)
+              }
+
+              entries(index) = ref.copy(nameRef = getOrAppendNameEntry(nameEntry.copy(name = parts.last)), ownerRef = myOwner)
+            }
+
+          case other =>
+            throw new RuntimeException(s"Ref entry does not point to a name but to a ${other.tag}")
+        }
+    }
+  }
+
+  // Return existing name entry or append a new one.
+  private def getOrAppendNameEntry(name: NameEntry): Int = {
+    nameIndices.getOrElse(name, appendEntry(name))
+  }
+
+  private def appendEntry(entry: TaggedEntry): Int = {
+    val index = entries.size
+    entries += entry
+
+    entry match {
+      case name: NameEntry =>
+        nameIndices.put(name, index)
+      case _ => // NoOp
+    }
+
+    index
+  }
+
+  // Resolves a ref into a fully qualified name
+  def resolveRef(extMod: RefEntry): Option[String] = {
+
+    val myName = entries(extMod.nameRef) match {
+      case term: NameEntry => term.name
+      case raw: RawEntry => throw new RuntimeException(s"Unexpected raw type for nameref ${raw.tag}")
+      case other => throw new RuntimeException(s"Unexpected type for nameref $other")
+    }
+    extMod.ownerRef match {
+      case None => Some(myName)
+      case Some(owner) =>
+        entries(owner) match {
+          case name: NameEntry =>
+            Some(s"$name/$myName")
+          case mod: RefEntry =>
+            resolveRef(mod).map(p => s"$p.$myName")
+          case raw: RawEntry if raw.tag == PickleFormat.NONEsym =>
+            None
+          case raw: RawEntry =>
+            throw new RuntimeException(s"Not a known owner type tag for $myName : ${raw.tag}")
+        }
+    }
+  }
+
+  /**
+   * Serializes this entry table into a byte array.
+   */
+  def toBytes: Array[Byte] = {
+    val os = new ByteArrayOutputStream()
+    val writer = new Nat.Writer {
+      override def writeByte(b: Int): Unit = os.write(b)
+    }
+
+    writer.writeNat(majorVersion)
+    writer.writeNat(minorVersion)
+    writer.writeNat(entries.size)
+
+    entries.foreach { entry =>
+      val payloadBytes = entry.toBytes
+      writer.writeNat(entry.tag)            // Tag of entry
+      writer.writeNat(payloadBytes.length)  // Size of payload
+      os.write(payloadBytes)
+    }
+
+    os.toByteArray
+  }
+}
+
+object EntryTable {
+
+  /**
+   * Parse bytes into a EntryTable
+   */
+  def fromBytes(bytes: Array[Byte]): EntryTable = {
+    val reader = new ByteArrayReader(bytes)
+
+    val majorVersion = reader.readNat()
+    val minorVersion = reader.readNat()
+
+    val result = new Array[TaggedEntry](reader.readNat())
+
+    result.indices foreach { index =>
+      val tag = reader.readNat()
+      val len = reader.readNat()
+
+      result(index) = TaggedEntry(tag, reader.readBytes(len))
+    }
+
+    new EntryTable(majorVersion, minorVersion, result.toBuffer)
+  }
+}