Prohibit await in if condition (for now)

Test nested loops.

Control ANF tracing with another system property.

6 files changed, 62 insertions, 20 deletions

diff --git a/src/main/scala/scala/async/AnfTransform.scala b/src/main/scala/scala/async/AnfTransform.scala
index 0756baf..cf6ed04 100644
--- a/src/main/scala/scala/async/AnfTransform.scala
+++ b/src/main/scala/scala/async/AnfTransform.scala
@@ -77,9 +77,9 @@ private[async] final case class AnfTransform[C <: Context](override val c: C) ex
     def apply[T](prefix: String, args: Any)(t: => T): T = {
       indent += 1
       try {
-        //println(s"${indentString}$prefix($args)")
+        AsyncUtils.trace(s"${indentString}$prefix($args)")
         val result = t
-        //println(s"${indentString}= $result")
+        AsyncUtils.trace(s"${indentString}= $result")
         result
       } finally {
         indent -= 1
diff --git a/src/main/scala/scala/async/AsyncAnalysis.scala b/src/main/scala/scala/async/AsyncAnalysis.scala
index e319fe8..c1ee7f4 100644
--- a/src/main/scala/scala/async/AsyncAnalysis.scala
+++ b/src/main/scala/scala/async/AsyncAnalysis.scala
@@ -62,6 +62,10 @@ private[async] final case class AsyncAnalysis[C <: Context](override val c: C) e
       tree match {
         case Try(_, _, _) if containsAwait =>
           reportUnsupportedAwait(tree, "try/catch")
+          super.traverse(tree)
+        case If(cond, _, _) if containsAwait =>
+          reportUnsupportedAwait(cond, "condition")
+          super.traverse(tree)
         case Return(_) =>
           c.abort(tree.pos, "return is illegal within a async block")
         case _ =>
diff --git a/src/main/scala/scala/async/AsyncUtils.scala b/src/main/scala/scala/async/AsyncUtils.scala
index b2f6747..525f187 100644
--- a/src/main/scala/scala/async/AsyncUtils.scala
+++ b/src/main/scala/scala/async/AsyncUtils.scala
@@ -8,8 +8,12 @@ package scala.async
  */
 object AsyncUtils {
 
-  private val verbose = false || sys.props.getOrElse("scala.async.debug", "false").equalsIgnoreCase("true")
-  
-  private[async] def vprintln(s: => Any): Unit = if (verbose)
-    println("[async] "+s)
+  private def enabled(level: String) = sys.props.getOrElse(s"scala.async.$level", "false").equalsIgnoreCase("true")
+
+  private val verbose = enabled("debug")
+  private val trace   = enabled("trace")
+
+  private[async] def vprintln(s: => Any): Unit = if (verbose) println(s"[async] $s")
+
+  private[async] def trace(s: => Any): Unit = if (trace) println(s"[async] $s")
 }
diff --git a/src/test/scala/scala/async/TreeInterrogation.scala b/src/test/scala/scala/async/TreeInterrogation.scala
index 08d2c78..485831b 100644
--- a/src/test/scala/scala/async/TreeInterrogation.scala
+++ b/src/test/scala/scala/async/TreeInterrogation.scala
@@ -32,29 +32,32 @@ class TreeInterrogation {
     val varDefs = tree1.collect {
       case ValDef(mods, name, _, _) if mods.hasFlag(Flag.MUTABLE) => name
     }
-    varDefs.map(_.decoded).toSet mustBe(Set("state$async", "onCompleteHandler$async", "await$1", "await$2"))
+    varDefs.map(_.decoded).toSet mustBe (Set("state$async", "onCompleteHandler$async", "await$1", "await$2"))
   }
 
-  @Test
+  //@Test
   def sandbox() {
-    sys.props("scala.async.debug") = "true"
+    sys.props("scala.async.debug") = true.toString
+    sys.props("scala.async.trace") = false.toString
+
     val cm = reflect.runtime.currentMirror
     val tb = mkToolbox("-cp target/scala-2.10/classes")
     val tree = tb.parse(
       """ import _root_.scala.async.AsyncId._
         | async {
-        |   var xxx: Int = 0
-        |   var y = 0
-        |   println("before while")
-        |   while (xxx < 3) {
-        |     println("in while before await")
-        |     y = await(xxx)
-        |     println("in while after await")
-        |     xxx = xxx + 1
+        |   var sum = 0
+        |   var i = 0
+        |   while (i < 5) {
+        |     var j = 0
+        |     while (j < 5) {
+        |       sum += await(i) * await(j)
+        |       j += 1
+        |     }
+        |     i += 1
         |   }
-        |   println("after while")
-        |   y
-        | }""".stripMargin)
+        |   sum
+        | }
+        | """.stripMargin)
     println(tree)
     val tree1 = tb.typeCheck(tree.duplicate)
     println(cm.universe.show(tree1))
diff --git a/src/test/scala/scala/async/neg/NakedAwait.scala b/src/test/scala/scala/async/neg/NakedAwait.scala
index 229feb6..b1c2d43 100644
--- a/src/test/scala/scala/async/neg/NakedAwait.scala
+++ b/src/test/scala/scala/async/neg/NakedAwait.scala
@@ -139,4 +139,15 @@ class NakedAwait {
         |""".stripMargin
     }
   }
+
+  // TODO Anf transform if to have a simple condition.
+  @Test
+  def ifCondition() {
+    expectError("await must not be used under a condition.") {
+      """
+        | import _root_.scala.async.AsyncId._
+        | async { if (await(true)) () }
+        |""".stripMargin
+    }
+  }
 }
diff --git a/src/test/scala/scala/async/run/ifelse0/WhileSpec.scala b/src/test/scala/scala/async/run/ifelse0/WhileSpec.scala
index d08e2c5..ba1d7a5 100644
--- a/src/test/scala/scala/async/run/ifelse0/WhileSpec.scala
+++ b/src/test/scala/scala/async/run/ifelse0/WhileSpec.scala
@@ -40,4 +40,24 @@ class WhileSpec {
     }
     result mustBe (0)
   }
+
+  @Test
+  def nestedWhile() {
+    import AsyncId._
+
+    val result = async {
+      var sum = 0
+      var i = 0
+      while (i < 5) {
+        var j = 0
+        while (j < 5) {
+          sum += await(i) * await(j)
+          j += 1
+        }
+        i += 1
+      }
+      sum
+    }
+    result mustBe (100)
+  }
 }
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