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, 4 insertions, 6 deletions

diff --git a/src/compiler/scala/tools/nsc/backend/icode/analysis/ReachingDefinitions.scala b/src/compiler/scala/tools/nsc/backend/icode/analysis/ReachingDefinitions.scala
index 31a2dbfbec..cc4619c68f 100644
--- a/src/compiler/scala/tools/nsc/backend/icode/analysis/ReachingDefinitions.scala
+++ b/src/compiler/scala/tools/nsc/backend/icode/analysis/ReachingDefinitions.scala
@@ -241,12 +241,10 @@ abstract class ReachingDefinitions {
       findDefs(bb, idx, m, 0)
 
     override def toString: String = {
-      val sb = new StringBuilder
-      sb.append("rdef: \n")
-      for (b <- method.code.blocks)
-        sb.append("rdef_entry(" + b + ")= " + in(b)).append("\nrdef_exit(" + b + ")= " + out(b))
-      sb.toString()
+      method.code.blocks map { b =>
+        "  entry(%s) = %s\n".format(b, in(b)) +
+        "   exit(%s) = %s\n".format(b, out(b))
+      } mkString ("ReachingDefinitions {\n", "\n", "\n}")
     }
-
   }
 }