Fixed duplicated local vars and wrong eliminati...

Fixed duplicated local vars and wrong elimination of useful closure
classes.

1 files changed, 11 insertions, 4 deletions

diff --git a/src/compiler/scala/tools/nsc/backend/opt/DeadCodeElimination.scala b/src/compiler/scala/tools/nsc/backend/opt/DeadCodeElimination.scala
index accd7d5aec..c36b8b4d42 100644
--- a/src/compiler/scala/tools/nsc/backend/opt/DeadCodeElimination.scala
+++ b/src/compiler/scala/tools/nsc/backend/opt/DeadCodeElimination.scala
@@ -41,6 +41,7 @@ abstract class DeadCodeElimination extends SubComponent {
   class DeadCode {
 
     def analyzeClass(cls: IClass): Unit = {
+      liveClosures.clear
       cls.methods.foreach { m =>
         this.method = m
 //        analyzeMethod(m);
@@ -62,6 +63,9 @@ abstract class DeadCodeElimination extends SubComponent {
     /** what local variables have been accessed at least once? */
     var accessedLocals: List[Local] = Nil
 
+    /** closures that are instantiated at least once, after dead code elimination */
+    val liveClosures: mutable.Set[Symbol] = new mutable.HashSet()
+
     /** the current method. */
     var method: IMethod = _
 
@@ -74,6 +78,7 @@ abstract class DeadCodeElimination extends SubComponent {
       collectRDef(m)
       mark
       sweep(m)
+      accessedLocals = accessedLocals.removeDuplicates
       if (m.locals.diff(accessedLocals).length > 0) {
         log("Removed dead locals: " + m.locals.diff(accessedLocals))
         m.locals = accessedLocals.reverse
@@ -126,9 +131,11 @@ abstract class DeadCodeElimination extends SubComponent {
               for ((l2, bb1, idx1) <- defs((bb, idx)) if l1 == l2; if !useful(bb1)(idx1))
                 worklist += ((bb1, idx1))
 
-            case nw @ NEW(_) =>
+            case nw @ NEW(REFERENCE(sym)) =>
               assert(nw.init ne null, "null new.init at: " + bb + ": " + idx + "(" + instr + ")")
               worklist += findInstruction(bb, nw.init)
+              if (inliner.isClosureClass(sym))
+                liveClosures += sym
 
             case LOAD_EXCEPTION() =>
               ()
@@ -168,10 +175,10 @@ abstract class DeadCodeElimination extends SubComponent {
           } else {
             i match {
               case NEW(REFERENCE(sym)) =>
-                log("skipped object creation: " + sym)
-                //Console.println("skipping class file altogether: " + sym.fullNameString)
-                if (inliner.isClosureClass(sym))
+                log("skipped object creation: " + sym + "inside " + m)
+                if (inliner.isClosureClass(sym) && !liveClosures(sym)) {
                   icodes.classes -= sym
+                }
               case _ => ()
             }
             if (settings.debug.value) log("Skipped: bb_" + bb + ": " + idx + "( " + i + ")")