add sbt plugin test

Author: liufengyun

compiler/src/dotty/tools/dotc/plugins/Plugins.scala

@@ -145,7 +145,7 @@ object Plugins {
    *  Note: this algorithm is factored out for unit test.
    */
   def schedule(plan: List[List[Phase]], pluginPhases: List[PluginPhase]): List[List[Phase]] = {
-    import scala.collection.mutable.{ Map => MMap, Set => MSet }
+    import scala.collection.mutable.{ Map => MMap }
     type OrderingReq = (Set[Class[_]], Set[Class[_]])
 
     val orderRequirements = MMap[Class[_], OrderingReq]()

sbt-dotty/sbt-test/sbt-dotty/compiler-plugin/build.sbt

@@ -0,0 +1,19 @@
+lazy val dottyVersion = sys.props("plugin.scalaVersion")
+
+lazy val pluginSetting = Seq(
+  name := "dividezero",
+  version := "0.0.1",
+  organization := "ch.epfl.lamp",
+  scalaVersion := dottyVersion,
+
+  libraryDependencies ++= Seq(
+    "ch.epfl.lamp" %% "dotty" % scalaVersion.value % "provided"
+  )
+)
+
+lazy val plugin = (project in file("plugin")).settings(pluginSetting: _*)
+
+lazy val app = (project in file(".")).settings(
+  scalaVersion := dottyVersion,
+  libraryDependencies += compilerPlugin("ch.epfl.lamp" %% "dividezero" % "0.0.1")
+)

sbt-dotty/sbt-test/sbt-dotty/compiler-plugin/plugin/DivideZero.scala

@@ -0,0 +1,40 @@
+package dividezero
+
+import dotty.tools.dotc._
+import core._
+import Contexts.Context
+import plugins.{Plugin, PluginPhase}
+import Phases.Phase
+import ast.tpd
+import transform.MegaPhase.MiniPhase
+import Decorators._
+import Symbols.Symbol
+import Constants.Constant
+import transform.{LinkAll, Pickler}
+
+class DivideZero extends PluginPhase with Plugin {
+  val name: String = "divideZero"
+  override val description: String = "divide zero check"
+
+  val phaseName = name
+
+  override val runsAfter = Set(classOf[Pickler])
+  override val runsBefore = Set(classOf[LinkAll])
+
+  override def init(options: List[String]): List[PluginPhase] = this :: Nil
+
+  private def isNumericDivide(sym: Symbol)(implicit ctx: Context): Boolean = {
+    def test(tpe: String): Boolean =
+      (sym.owner eq ctx.requiredClass(tpe.toTermName)) && sym.name.show == "/"
+
+    test("scala.Int") || test("scala.Long") || test("scala.Short") || test("scala.FLoat") || test("scala.Double")
+  }
+
+  override def transformApply(tree: tpd.Apply)(implicit ctx: Context): tpd.Tree = tree match {
+    case tpd.Apply(fun, tpd.Literal(Constants.Constant(v)) :: Nil) if isNumericDivide(fun.symbol) && v == 0 =>
+      ctx.warning("divide by zero", tree.pos)
+      tpd.Literal(Constant(0))
+    case _ =>
+      tree
+  }
+}

sbt-dotty/sbt-test/sbt-dotty/compiler-plugin/plugin/src/main/resources/scalac-plugin.xml

@@ -0,0 +1,4 @@
+<plugin>
+  <name>divideZero</name>
+  <classname>dividezero.DivideZero</classname>
+</plugin>

sbt-dotty/sbt-test/sbt-dotty/compiler-plugin/project/build.properties

@@ -0,0 +1 @@
+sbt.version=0.13.15

sbt-dotty/sbt-test/sbt-dotty/compiler-plugin/project/plugins.sbt

@@ -0,0 +1 @@
+addSbtPlugin("ch.epfl.lamp" % "sbt-dotty" % sys.props("plugin.version"))

sbt-dotty/sbt-test/sbt-dotty/compiler-plugin/src/main/scala/hello/Hello.scala

@@ -0,0 +1,13 @@
+package hello
+object Hello {
+  def main(args: Array[String]): Unit = {
+    val dotty: Int | String = "dotty"
+
+    val y = 5 / 0 // error
+    100 + 6 / 0 // error
+    6L / 0L // error
+    val z = 7 / 0.0 // error
+
+    println(s"Hello $dotty!")
+  }
+}

sbt-dotty/sbt-test/sbt-dotty/compiler-plugin/test

@@ -0,0 +1,5 @@
+> plugin/publishLocal
+> run
+> 'set initialCommands := "1 + 1" '
+# FIXME: does not work on the CI
+#> console