scalac portion of fix for #2689.

3 files changed, 43 insertions, 1 deletions

diff --git a/src/compiler/scala/tools/nsc/Settings.scala b/src/compiler/scala/tools/nsc/Settings.scala
index 23ceb37c95..b039a9e90d 100644
--- a/src/compiler/scala/tools/nsc/Settings.scala
+++ b/src/compiler/scala/tools/nsc/Settings.scala
@@ -372,6 +372,37 @@ object Settings {
           }
       }
     }
+
+    /** Return the source file path(s) which correspond to the given
+     *  classfile path and SourceFile attribute value, subject to the
+     *  condition that source files are arranged in the filesystem
+     *  according to Java package layout conventions.
+     *
+     *  The given classfile path must be contained in at least one of
+     *  the specified output directories. If it does not then this
+     *  method returns Nil.
+     *
+     *  Note that the source file is not required to exist, so assuming
+     *  a valid classfile path this method will always return a list
+     *  containing at least one element.
+     *
+     *  Also that if two or more source path elements target the same
+     *  output directory there will be two or more candidate source file
+     *  paths.
+     */
+    def srcFilesFor(classFile : AbstractFile, srcPath : String) : List[AbstractFile] = {
+      def isBelow(srcDir: AbstractFile, outDir: AbstractFile) =
+        classFile.path.startsWith(outDir.path)
+
+      singleOutDir match {
+        case Some(d) => Nil
+        case None =>
+          (outputs filter (isBelow _).tuple) match {
+            case Nil => Nil
+            case matches => matches.map(_._1.lookupPath(srcPath, false))
+          }
+      }
+    }
   }
 
   // The Setting companion object holds all the factory methods
diff --git a/src/compiler/scala/tools/nsc/symtab/SymbolLoaders.scala b/src/compiler/scala/tools/nsc/symtab/SymbolLoaders.scala
index 5d779e90a2..3daa4e8ac2 100644
--- a/src/compiler/scala/tools/nsc/symtab/SymbolLoaders.scala
+++ b/src/compiler/scala/tools/nsc/symtab/SymbolLoaders.scala
@@ -249,6 +249,7 @@ abstract class SymbolLoaders {
       classfileParser.parse(classfile, root)
       stopTimer(classReadNanos, start)
     }
+    override protected def sourcefile = classfileParser.srcfile
   }
 
   class MSILTypeLoader(typ: MSILType) extends SymbolLoader {
diff --git a/src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala b/src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala
index da4e0aaa49..5c4679625b 100644
--- a/src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala
+++ b/src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala
@@ -8,7 +8,7 @@ package scala.tools.nsc
 package symtab
 package classfile
 
-import java.io.IOException
+import java.io.{ File, IOException }
 import java.lang.Integer.toHexString
 
 import scala.collection.immutable.{Map, ListMap}
@@ -41,6 +41,9 @@ abstract class ClassfileParser {
   protected var busy: Option[Symbol] = None // lock to detect recursive reads
   private var   externalName: Name = _      // JVM name of the current class
   protected var classTParams = Map[Name,Symbol]()
+  protected var srcfile0 : Option[AbstractFile] = None
+
+  def srcfile = srcfile0
 
   private object metaParser extends MetaParser {
     val global: ClassfileParser.this.global.type = ClassfileParser.this.global
@@ -813,6 +816,13 @@ abstract class ClassfileParser {
         case nme.ExceptionsATTR if (!isScala) =>
           parseExceptions(attrLen)
 
+        case nme.SourceFileATTR =>
+          val srcfileLeaf = pool.getName(in.nextChar).toString.trim
+          val srcpath = sym.enclosingPackage match {
+            case NoSymbol => srcfileLeaf
+            case pkg => pkg.fullNameString(File.separatorChar)+File.separator+srcfileLeaf
+          }
+          srcfile0 = settings.outputDirs.srcFilesFor(in.file, srcpath).find(_.exists)
         case _ =>
           in.skip(attrLen)
       }