Replacematcherror - catch exceptions and convert to internal error. (#424)

* Catch exceptions and convert to internal error.
We need to update the displayed message to incorporate a line number and text to be used for the issue.

* Cleanup exception handling/throwing.
Re-throw expected (or uncorrectable exceptions).
Provide Utils.getThrowable() to get the first (eldest) or last throwable in the chain.
Update tests to conform to FreeSpec protocol.

* Minor cleanup
Admit we've updated some deprecated ScalaTest methods.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/main/scala/firrtl/passes/InferWidths.scala b/src/main/scala/firrtl/passes/InferWidths.scala
index 11b819ce..aacd3656 100644
--- a/src/main/scala/firrtl/passes/InferWidths.scala
+++ b/src/main/scala/firrtl/passes/InferWidths.scala
@@ -333,7 +333,7 @@ object InferWidths extends Pass {
         case wx: MinusWidth => map2(solve(wx.arg1), solve(wx.arg2), {_ - _})
         case wx: ExpWidth => map2(Some(BigInt(2)), solve(wx.arg1), pow_minus_one)
         case wx: IntWidth => Some(wx.width)
-        case wx => println(wx); error("Shouldn't be here"); None;
+        case wx => throwInternalError(Some(s"solve: shouldn't be here - %$wx")); None;
       }
 
       solve(w) match {