Fixed a bug in the optimizer which was preventi...

Fixed a bug in the optimizer which was preventing private methods from
being inlined. Also relaxes a condition related to the "liftedTry"
problem: the inliner has to exclude certain methods from consideration
if there is a value on the stack and the method being inlined has
exception handlers. The new condition is as before, except that it does
not exclude methods of the "try/finally" variety (i.e. finalizers, but
no other exception handlers.) This is necessary to optimize this common
pattern:

  @inline private def foo(body: => Unit) {
    val saved = something
    try body
    finally something = saved
  }

The closure for "body" can be fully eliminated, but only if the contents
of foo can be inlined into the caller.

Closes #4764, review by rompf.

1 files changed, 5 insertions, 1 deletions

diff --git a/src/compiler/scala/tools/nsc/backend/icode/analysis/SemiLattice.scala b/src/compiler/scala/tools/nsc/backend/icode/analysis/SemiLattice.scala
index d458b2546f..cfce0878ed 100644
--- a/src/compiler/scala/tools/nsc/backend/icode/analysis/SemiLattice.scala
+++ b/src/compiler/scala/tools/nsc/backend/icode/analysis/SemiLattice.scala
@@ -3,7 +3,6 @@
  * @author  Martin Odersky
  */
 
-
 package scala.tools.nsc
 package backend.icode
 package analysis
@@ -26,6 +25,11 @@ trait SemiLattice {
       case _ =>
         false
     }
+    private def tstring(x: Any): String = x match {
+      case xs: TraversableOnce[_] => xs map tstring mkString " "
+      case _                      => "" + x
+    }
+    override def toString = "IState(" + tstring(vars) + ", " + tstring(stack) + ")"
   }
 
   /** Return the least upper bound of a and b. */