Escape control characters in Printf string literals

If we end up generalizing Strings, this code should be moved elsewhere.

Note FIRRTL doesn't handle this stuff right, so I'm not committing the
companion test yet.

1 files changed, 11 insertions, 1 deletions

diff --git a/src/main/scala/Chisel/internal/firrtl/IR.scala b/src/main/scala/Chisel/internal/firrtl/IR.scala
index 7bb273c0..6946652f 100644
--- a/src/main/scala/Chisel/internal/firrtl/IR.scala
+++ b/src/main/scala/Chisel/internal/firrtl/IR.scala
@@ -161,9 +161,19 @@ case class Connect(loc: Node, exp: Arg) extends Command
 case class BulkConnect(loc1: Node, loc2: Node) extends Command
 case class ConnectInit(loc: Node, exp: Arg) extends Command
 case class Stop(clk: Arg, ret: Int) extends Command
-case class Printf(clk: Arg, format: String, ids: Seq[Arg]) extends Command
 case class Component(id: Module, name: String, ports: Seq[Port], commands: Seq[Command]) extends Arg
 case class Port(id: Data, dir: Direction)
+case class Printf(clk: Arg, formatIn: String, ids: Seq[Arg]) extends Command {
+  require(formatIn.forall(c => c.toInt > 0 && c.toInt < 128), "format strings must comprise non-null ASCII values")
+  def format = {
+    def escaped(x: Char) =
+      if (x == '"' || x == '\\' || x == '?') "\\" + x
+      else if (x == '\n') "\\n"
+      else if (x.toInt < 32) s"\\x${BigInt(x.toInt).toString(16)}"
+      else x
+    formatIn.map(escaped _).mkString
+  }
+}
 
 case class Circuit(name: String, components: Seq[Component], refMap: RefMap) {
   def emit: String = new Emitter(this).toString