Merged in Scala implementation of FIRRTL IR, parser, and serialization (ie. AST -> String). Uses ANTLRv4 to generate concrete syntax parser

1 files changed, 44 insertions, 0 deletions

diff --git a/src/main/scala/firrtl/Parser.scala b/src/main/scala/firrtl/Parser.scala
new file mode 100644
index 00000000..35e41222
--- /dev/null
+++ b/src/main/scala/firrtl/Parser.scala
@@ -0,0 +1,44 @@
+package firrtl
+
+import org.antlr.v4.runtime._;
+import org.antlr.v4.runtime.atn._;
+import org.antlr.v4.runtime.tree._;
+import java.io.FileInputStream
+import scala.collection.JavaConverters._
+import scala.io.Source
+import Utils._
+import antlr._
+
+object Parser
+{
+
+  /** Takes a firrtl filename, returns AST (root node is Circuit)
+    *
+    * Currently must be standard FIRRTL file
+    * Parser performs conversion to machine firrtl
+    */
+  def parse(filename: String): Circuit = {
+    //val antlrStream = new ANTLRInputStream(input.reader) 
+    val fixedInput = Translator.addBrackets(Source.fromFile(filename).getLines)
+    val antlrStream = new ANTLRInputStream(fixedInput.result)
+    val lexer = new FIRRTLLexer(antlrStream)
+    val tokens = new CommonTokenStream(lexer)
+    val parser = new FIRRTLParser(tokens)
+
+    // FIXME Dangerous
+    parser.getInterpreter.setPredictionMode(PredictionMode.SLL)
+
+    // Concrete Syntax Tree
+    val cst = parser.circuit
+
+    val visitor = new Visitor(filename) 
+    //val ast = visitor.visitCircuit(cst) match {
+    val ast = visitor.visit(cst) match {
+      case c: Circuit => c
+      case x => throw new ClassCastException("Error! AST not rooted with Circuit node!")
+    }
+
+    ast
+  }
+
+}