Improve Parser and Visitor (#819)

* Update Parser to use ANTLR CharStreams

This removes some unnecessary object creation in String reading and
manipulation

* Remove two unnecessary traversals from Block construction in Visitor

1 files changed, 2 insertions, 3 deletions

diff --git a/src/main/scala/firrtl/Driver.scala b/src/main/scala/firrtl/Driver.scala
index 72128274..ddc06d2a 100644
--- a/src/main/scala/firrtl/Driver.scala
+++ b/src/main/scala/firrtl/Driver.scala
@@ -169,7 +169,7 @@ object Driver {
         throw new OptionsException(msg)
       }
       firrtlConfig.firrtlCircuit.getOrElse {
-        val source = firrtlConfig.firrtlSource.map(_.split("\n").toIterator).getOrElse {
+        firrtlConfig.firrtlSource.map(x => Parser.parseString(x, firrtlConfig.infoMode)).getOrElse {
           if (optionsManager.topName.isEmpty && firrtlConfig.inputFileNameOverride.isEmpty) {
             val message = "either top-name or input-file-override must be set"
             throw new OptionsException(message)
@@ -183,7 +183,7 @@ object Driver {
           }
           val inputFileName = firrtlConfig.getInputFileName(optionsManager)
           try {
-            io.Source.fromFile(inputFileName).getLines()
+            Parser.parseFile(inputFileName, firrtlConfig.infoMode)
           }
           catch {
             case _: FileNotFoundException =>
@@ -191,7 +191,6 @@ object Driver {
               throw new OptionsException(message)
           }
         }
-        Parser.parse(source, firrtlConfig.infoMode)
       }
     }
   }