From 58abe39c9d8d75bc2c5ca27e1b8c0c33de9e6824 Mon Sep 17 00:00:00 2001
From: Jason Zaugg <jzaugg@gmail.com>
Date: Thu, 13 Jun 2013 14:32:49 -0400
Subject: SI-7433 Fix spurious warning about catching control throwable

In the same vein as SI-6994, we have to be careful not to warn
about synthetic code. In that case, the spurious warnings came
because we warned in the typechecker, which was also called in
erasure. In this case, we are issuing the warning in Uncurry,
so we must be mindful of the pattern matchers translations of
non-trivial catch patterns, which look like:

    case (ex8 @ _) => {
    <synthetic> val x5: Throwable = ex8;
    case11(){
      if ({
        case14(){
          if (x5.$isInstanceOf[NullPointerException]())
            matchEnd13(true)
          else
            case15()
        };
        case15(){
          if (x5.$isInstanceOf[RuntimeException]())
            matchEnd13(true)
          else
            case16()
        };
        case16(){
          matchEnd13(false)
        };
        matchEnd13(x: Boolean){
          x
        }
      })

This commit detects that `ex8` is synthetic and disables the warning.
---
 src/reflect/scala/reflect/internal/TreeInfo.scala | 6 ++++++
 1 file changed, 6 insertions(+)

(limited to 'src/reflect')

diff --git a/src/reflect/scala/reflect/internal/TreeInfo.scala b/src/reflect/scala/reflect/internal/TreeInfo.scala
index 3a8d3fd460..30ec555bc5 100644
--- a/src/reflect/scala/reflect/internal/TreeInfo.scala
+++ b/src/reflect/scala/reflect/internal/TreeInfo.scala
@@ -553,6 +553,12 @@ abstract class TreeInfo {
     })
   )
 
+  /** Is this CaseDef synthetically generated, e.g. by `MatchTranslation.translateTry`? */
+  def isSyntheticCase(cdef: CaseDef) = cdef.pat.exists {
+    case dt: DefTree => dt.symbol.isSynthetic
+    case _           => false
+  }
+
   /** Is this pattern node a catch-all or type-test pattern? */
   def isCatchCase(cdef: CaseDef) = cdef match {
     case CaseDef(Typed(Ident(nme.WILDCARD), tpt), EmptyTree, _) =>
-- 
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