verify classpath feature to identify duplicate classes

2 files changed, 33 insertions, 2 deletions

diff --git a/stage1/ClassPath.scala b/stage1/ClassPath.scala
index 539efc7..b13bdaf 100644
--- a/stage1/ClassPath.scala
+++ b/stage1/ClassPath.scala
@@ -27,4 +27,34 @@ case class ClassPath(files: Seq[File] = Seq()){
       if( f.getName.endsWith(".jar") /* !f.isDirectory */ ) "" else "/"
     )
   }.sorted
+
+  def verify( lib: Stage1Lib ) = {
+    val ( directories, jarFiles ) = files.partition(_.isDirectory)
+    val all = lib.autoRelative(
+      directories
+    ) ++ jarFiles.flatMap{ f => 
+      import collection.JavaConverters._
+      new java.util.jar.JarFile(f).entries.asScala.filterNot(_.isDirectory).toVector.map(
+        f -> _.toString
+      )
+    }
+    val duplicates =
+      all
+        .groupBy( _._2 )
+        .filter( _._2.size > 1 )
+        .filter( _._1 endsWith ".class" )
+        .mapValues( _.map( _._1 ) )
+        .toSeq
+        .sortBy( _._1 )
+    assert(
+      duplicates.isEmpty,
+      {
+        "Conflicting:\n\n" +
+        duplicates.map{
+          case ( path, locations ) =>
+            path + " exits in multiple locations:\n" + locations.mkString("\n")
+        }.mkString("\n\n")
+      }
+    )
+  }
 }
diff --git a/stage1/resolver.scala b/stage1/resolver.scala
index 48099e5..f4a9b13 100644
--- a/stage1/resolver.scala
+++ b/stage1/resolver.scala
@@ -130,8 +130,9 @@ trait DependencyImplementation extends Dependency{
   }
 
   // FIXME: these probably need to update outdated as well
-  def classpath           : ClassPath = exportedClasspath ++ dependencyClasspath
-  def dependencyClasspath : ClassPath = taskCache[DependencyImplementation]( "dependencyClasspath" ).memoize{
+  def classpath: ClassPath = exportedClasspath ++ dependencyClasspath
+  def verifyClasspath: Unit = classpath.verify(lib)
+  def dependencyClasspath: ClassPath = taskCache[DependencyImplementation]( "dependencyClasspath" ).memoize{
     ClassPath(
       transitiveDependencies
       .flatMap(_.exportedClasspath.files)