First pass at providing new pretty-prints for build `Module`s/`Target`s/`Cross`s in the Mill REPL, making use of `sourcecode.*` values captured and definition-site and contextual information made available in the build `Mirror`

18 files changed, 146 insertions, 41 deletions

diff --git a/core/src/main/scala/mill/Main.scala b/core/src/main/scala/mill/Main.scala
index 3a00bdb8..66f7ee59 100644
--- a/core/src/main/scala/mill/Main.scala
+++ b/core/src/main/scala/mill/Main.scala
@@ -46,7 +46,8 @@ object Main {
           else cliConfig.copy(
             predefCode =
               """import $file.build, build._
-                |implicit val replApplyHandler = mill.main.ReplApplyHandler(build.mapping)
+                |implicit val replApplyHandler = mill.main.ReplApplyHandler(repl.pprinter(), build.mapping)
+                |repl.pprinter() = replApplyHandler.pprinter
                 |import replApplyHandler.generatedEval._
                 |
               """.stripMargin,
diff --git a/core/src/main/scala/mill/define/Cross.scala b/core/src/main/scala/mill/define/Cross.scala
index 55d7b59c..90a383a6 100644
--- a/core/src/main/scala/mill/define/Cross.scala
+++ b/core/src/main/scala/mill/define/Cross.scala
@@ -1,6 +1,6 @@
 package mill.define
 
-case class Cross[+T](items: List[(List[Any], T)]){
+case class Cross[+T](items: List[(List[Any], T)])(implicit val e: sourcecode.Enclosing, val l: sourcecode.Line){
   def flatMap[V](f: T => Cross[V]): Cross[V] = new Cross(
     items.flatMap{
       case (l, v) => f(v).items.map{case (l2, v2) => (l2 ::: l, v2)}
@@ -27,4 +27,5 @@ object Cross{
 }
 
 class CrossModule[T, V](constructor: T => V, cases: T*)
+                       (implicit e: sourcecode.Enclosing, l: sourcecode.Line)
 extends Cross[V](cases.toList.map(x => (List(x), constructor(x))))
\ No newline at end of file
diff --git a/core/src/main/scala/mill/define/Task.scala b/core/src/main/scala/mill/define/Task.scala
index b29f173b..6ee9c606 100644
--- a/core/src/main/scala/mill/define/Task.scala
+++ b/core/src/main/scala/mill/define/Task.scala
@@ -42,6 +42,7 @@ trait NamedTask[+T] extends Task[T]{
 trait Target[+T] extends NamedTask[T]{
   override def asTarget = Some(this)
   def enclosing: String
+  def lineNum: Int
   def readWrite: RW[_]
 }
 
@@ -51,6 +52,7 @@ object Target extends TargetGenerated with Applicative.Applyer[Task, Task, Resul
                        (implicit r: R[T],
                         w: W[T],
                         e: sourcecode.Enclosing,
+                        l: sourcecode.Line,
                         n: sourcecode.Name,
                         cl: Caller[mill.define.Task.Module],
                         o: Overrides): Target[T] = macro targetImpl[T]
@@ -60,6 +62,7 @@ object Target extends TargetGenerated with Applicative.Applyer[Task, Task, Resul
                                   (r: c.Expr[R[T]],
                                    w: c.Expr[W[T]],
                                    e: c.Expr[sourcecode.Enclosing],
+                                   l: c.Expr[sourcecode.Line],
                                    n: c.Expr[sourcecode.Name],
                                    cl: c.Expr[Caller[mill.define.Task.Module]],
                                    o: c.Expr[Overrides]): c.Expr[Target[T]] = {
@@ -71,6 +74,7 @@ object Target extends TargetGenerated with Applicative.Applyer[Task, Task, Resul
         new TargetImpl[T](
           lhs.splice,
           e.splice.value,
+          l.splice.value,
           cl.splice.value,
           n.splice.value,
           upickle.default.ReadWriter(w.splice.write, r.splice.read), o.splice.value
@@ -83,6 +87,7 @@ object Target extends TargetGenerated with Applicative.Applyer[Task, Task, Resul
                        (implicit r: R[T],
                         w: W[T],
                         e: sourcecode.Enclosing,
+                        l: sourcecode.Line,
                         n: sourcecode.Name,
                         cl: Caller[mill.define.Task.Module],
                         o: Overrides): Target[T] = macro targetResultImpl[T]
@@ -92,6 +97,7 @@ object Target extends TargetGenerated with Applicative.Applyer[Task, Task, Resul
                                         (r: c.Expr[R[T]],
                                          w: c.Expr[W[T]],
                                          e: c.Expr[sourcecode.Enclosing],
+                                         l: c.Expr[sourcecode.Line],
                                          n: c.Expr[sourcecode.Name],
                                          cl: c.Expr[Caller[mill.define.Task.Module]],
                                          o: c.Expr[Overrides]): c.Expr[Target[T]] = {
@@ -101,6 +107,7 @@ object Target extends TargetGenerated with Applicative.Applyer[Task, Task, Resul
         new TargetImpl[T](
           Applicative.impl0[Task, T, Ctx](c)(t.tree).splice,
           e.splice.value,
+          l.splice.value,
           cl.splice.value,
           n.splice.value,
           upickle.default.ReadWriter(w.splice.write, r.splice.read),
@@ -114,6 +121,7 @@ object Target extends TargetGenerated with Applicative.Applyer[Task, Task, Resul
               (implicit r: R[T],
                w: W[T],
                e: sourcecode.Enclosing,
+               l: sourcecode.Line,
                n: sourcecode.Name,
                cl: Caller[mill.define.Task.Module],
                o: Overrides): Target[T] = macro targetTaskImpl[T]
@@ -123,6 +131,7 @@ object Target extends TargetGenerated with Applicative.Applyer[Task, Task, Resul
                                       (r: c.Expr[R[T]],
                                        w: c.Expr[W[T]],
                                        e: c.Expr[sourcecode.Enclosing],
+                                       l: c.Expr[sourcecode.Line],
                                        n: c.Expr[sourcecode.Name],
                                        cl: c.Expr[Caller[mill.define.Task.Module]],
                                        o: c.Expr[Overrides]): c.Expr[Target[T]] = {
@@ -132,6 +141,7 @@ object Target extends TargetGenerated with Applicative.Applyer[Task, Task, Resul
         new TargetImpl[T](
           t.splice,
           e.splice.value,
+          l.splice.value,
           cl.splice.value,
           n.splice.value,
           upickle.default.ReadWriter(w.splice.write, r.splice.read),
@@ -152,6 +162,7 @@ object Target extends TargetGenerated with Applicative.Applyer[Task, Task, Resul
             (implicit r: R[PathRef],
              w: W[PathRef],
              e: sourcecode.Enclosing,
+             l: sourcecode.Line,
              n: sourcecode.Name,
              cl: Caller[mill.define.Task.Module],
              o: Overrides): Input[PathRef] = macro sourceImpl
@@ -161,6 +172,7 @@ object Target extends TargetGenerated with Applicative.Applyer[Task, Task, Resul
                 (r: c.Expr[R[PathRef]],
                  w: c.Expr[W[PathRef]],
                  e: c.Expr[sourcecode.Enclosing],
+                 l: c.Expr[sourcecode.Line],
                  n: c.Expr[sourcecode.Name],
                  cl: c.Expr[Caller[mill.define.Task.Module]],
                  o: c.Expr[Overrides]): c.Expr[Input[PathRef]] = {
@@ -174,6 +186,7 @@ object Target extends TargetGenerated with Applicative.Applyer[Task, Task, Resul
         new Input[PathRef](
           Applicative.impl0[Task, PathRef, Ctx](c)(wrapped.tree).splice,
           e.splice.value,
+          l.splice.value,
           cl.splice.value,
           n.splice.value,
           upickle.default.ReadWriter(w.splice.write, r.splice.read),
@@ -187,6 +200,7 @@ object Target extends TargetGenerated with Applicative.Applyer[Task, Task, Resul
               (implicit r: R[T],
                 w: W[T],
                 e: sourcecode.Enclosing,
+                l: sourcecode.Line,
                 n: sourcecode.Name,
                 cl: Caller[mill.define.Task.Module],
                 o: Overrides): Input[T] = macro inputImpl[T]
@@ -196,6 +210,7 @@ object Target extends TargetGenerated with Applicative.Applyer[Task, Task, Resul
                                   (r: c.Expr[R[T]],
                                    w: c.Expr[W[T]],
                                    e: c.Expr[sourcecode.Enclosing],
+                                   l: c.Expr[sourcecode.Line],
                                    n: c.Expr[sourcecode.Name],
                                    cl: c.Expr[Caller[mill.define.Task.Module]],
                                    o: c.Expr[Overrides]): c.Expr[Input[T]] = {
@@ -206,6 +221,7 @@ object Target extends TargetGenerated with Applicative.Applyer[Task, Task, Resul
         new Input[T](
           Applicative.impl[Task, T, Ctx](c)(value).splice,
           e.splice.value,
+          l.splice.value,
           cl.splice.value,
           n.splice.value,
           upickle.default.ReadWriter(w.splice.write, r.splice.read),
@@ -247,6 +263,7 @@ object Target extends TargetGenerated with Applicative.Applyer[Task, Task, Resul
   def persistent[T](t: Result[T])(implicit r: R[T],
                                   w: W[T],
                                   e: sourcecode.Enclosing,
+                                  l: sourcecode.Line,
                                   n: sourcecode.Name,
                                   cl: Caller[mill.define.Task.Module],
                                   o: Overrides): Target[T] = macro persistentImpl[T]
@@ -256,6 +273,7 @@ object Target extends TargetGenerated with Applicative.Applyer[Task, Task, Resul
                                       (r: c.Expr[R[T]],
                                        w: c.Expr[W[T]],
                                        e: c.Expr[sourcecode.Enclosing],
+                                       l: c.Expr[sourcecode.Line],
                                        n: c.Expr[sourcecode.Name],
                                        cl: c.Expr[Caller[mill.define.Task.Module]],
                                        o: c.Expr[Overrides]): c.Expr[Persistent[T]] = {
@@ -267,6 +285,7 @@ object Target extends TargetGenerated with Applicative.Applyer[Task, Task, Resul
         new Persistent[T](
           Applicative.impl[Task, T, Ctx](c)(t).splice,
           e.splice.value,
+          l.splice.value,
           cl.splice.value,
           n.splice.value,
           upickle.default.ReadWriter(w.splice.write, r.splice.read),
@@ -301,6 +320,7 @@ object Caller {
 
 class TargetImpl[+T](t: Task[T],
                      val enclosing: String,
+                     val lineNum: Int,
                      val owner: Task.Module,
                      val name: String,
                      val readWrite: RW[_],
@@ -321,16 +341,18 @@ class Command[+T](t: Task[T],
 }
 class Persistent[+T](t: Task[T],
                      enclosing: String,
+                     lineNum: Int,
                      owner: Task.Module,
                      name: String,
                      readWrite: RW[_],
                      overrides: Int)
-  extends TargetImpl[T](t, enclosing, owner, name, readWrite, overrides) {
+  extends TargetImpl[T](t, enclosing, lineNum, owner, name, readWrite, overrides) {
   override def flushDest = false
   override def asPersistent = Some(this)
 }
 class Input[T](t: Task[T],
                val enclosing: String,
+               val lineNum: Int,
                val owner: Task.Module,
                val name: String,
                val readWrite: RW[_],
@@ -346,7 +368,21 @@ object Task {
   trait TaskModule extends Module {
     def defaultCommandName(): String
   }
-  trait Module extends mill.moduledefs.Cacher
+
+  /**
+    * `Module` is a class meant to be extended by `trait`s *only*, in order to
+    * propagate the implicit parameters forward to the final concrete
+    * instantiation site so they can capture the enclosing/line information of
+    * the concrete instance.
+    */
+  class Module(implicit millModuleEnclosing0: sourcecode.Enclosing,
+               millModuleLine0: sourcecode.Line) extends mill.moduledefs.Cacher{
+    // Ensure we do not propagate the implicit parameters as implicits within
+    // the body of any inheriting class/trait/objects, as it would screw up any
+    // one else trying to use sourcecode.{Enclosing,Line} to capture debug info
+    val millModuleEnclosing = millModuleEnclosing0
+    val millModuleLine = millModuleLine0
+  }
 
   class Task0[T](t: T) extends Task[T]{
     lazy val t0 = t
diff --git a/core/src/main/scala/mill/discover/Discovered.scala b/core/src/main/scala/mill/discover/Discovered.scala
index 9528a310..58e2c3bb 100644
--- a/core/src/main/scala/mill/discover/Discovered.scala
+++ b/core/src/main/scala/mill/discover/Discovered.scala
@@ -24,7 +24,7 @@ object Discovered {
   }
   case class Mapping[T](mirror: Mirror[T, T],
                         base: T){
-    val modules = Mirror.traverse(base, mirror){ (mirror, segmentsRev) =>
+    val modulesToPaths = Mirror.traverse(base, mirror){ (mirror, segmentsRev) =>
       val resolvedNode = mirror.node(
         base,
         segmentsRev.reverse.map{case Mirror.Segment.Cross(vs) => vs.toList case _ => Nil}.toList
@@ -32,7 +32,15 @@ object Discovered {
       Seq(resolvedNode -> segmentsRev.reverse)
     }.toMap
 
-    val targets = Mirror.traverse(base, mirror){ (mirror, segmentsRev) =>
+    val modulesToMirrors = Mirror.traverse[T, T, (Any, Mirror[_, _])](base, mirror){ (mirror, segmentsRev) =>
+      val resolvedNode = mirror.node(
+        base,
+        segmentsRev.reverse.map{case Mirror.Segment.Cross(vs) => vs.toList case _ => Nil}.toList
+      )
+      Seq(resolvedNode -> mirror)
+    }.toMap
+
+    val targetsToSegments = Mirror.traverse(base, mirror){ (mirror, segmentsRev) =>
       val resolvedNode = mirror.node(
         base,
         segmentsRev.reverse.map{case Mirror.Segment.Cross(vs) => vs.toList case _ => Nil}.toList
@@ -48,14 +56,14 @@ object Discovered {
       yield (segmentsRev.reverse :+ Segment.Label(command.name)) -> command
     }.toMap
 
-    val segmentsToTargets = targets.map(_.swap)
+    val segmentsToTargets = targetsToSegments.map(_.swap)
   }
 
   def consistencyCheck[T](mapping: Discovered.Mapping[T]) = {
     val mapping2 = Discovered.Mapping(mapping.mirror, mapping.base)
 
     for{
-      (t1, t2) <- mapping2.targets.zip(mapping.targets)
+      (t1, t2) <- mapping2.targetsToSegments.zip(mapping.targetsToSegments)
       if t1._1 ne t2._1
     } yield t1._2
   }
diff --git a/core/src/main/scala/mill/discover/Mirror.scala b/core/src/main/scala/mill/discover/Mirror.scala
index 42339fd7..63b6900b 100644
--- a/core/src/main/scala/mill/discover/Mirror.scala
+++ b/core/src/main/scala/mill/discover/Mirror.scala
@@ -20,13 +20,14 @@ case class Mirror[-T, V](node: (T, List[List[Any]]) => V,
                          crossChildren: Option[(V => List[List[Any]], Mirror[T, _])])
 
 object Mirror{
-  def renderSelector(selector: Seq[Mirror.Segment]) = {
-    val Mirror.Segment.Label(head) :: rest = selector.toList
-    val stringSegments = rest.map{
-      case Mirror.Segment.Label(s) => "." + s
-      case Mirror.Segment.Cross(vs) => "[" + vs.mkString(",") + "]"
-    }
-    head + stringSegments.mkString
+  def renderSelector(selector: Seq[Mirror.Segment]) = selector.toList match {
+    case Nil => ""
+    case Mirror.Segment.Label(head) :: rest =>
+      val stringSegments = rest.map{
+        case Mirror.Segment.Label(s) => "." + s
+        case Mirror.Segment.Cross(vs) => "[" + vs.mkString(",") + "]"
+      }
+      head + stringSegments.mkString
   }
 
   sealed trait Segment
diff --git a/core/src/main/scala/mill/eval/Evaluator.scala b/core/src/main/scala/mill/eval/Evaluator.scala
index 5aa3439c..ccb81da3 100644
--- a/core/src/main/scala/mill/eval/Evaluator.scala
+++ b/core/src/main/scala/mill/eval/Evaluator.scala
@@ -40,8 +40,8 @@ class Evaluator[T](val workspacePath: Path,
     val transitive = Graph.transitiveTargets(goals)
     val topoSorted = Graph.topoSorted(transitive)
     val sortedGroups = Graph.groupAroundImportantTargets(topoSorted){
-      case t: NamedTask[Any] if mapping.modules.contains(t.owner)  =>
-        val segments = mapping.modules(t.owner) :+ Segment.Label(t.name)
+      case t: NamedTask[Any] if mapping.modulesToPaths.contains(t.owner)  =>
+        val segments = mapping.modulesToPaths(t.owner) :+ Segment.Label(t.name)
         val (finalTaskOverrides, enclosing) = t match{
           case t: Target[_] => mapping.segmentsToTargets(segments).overrides -> t.enclosing
           case c: mill.define.Command[_] => mapping.segmentsToCommands(segments).overrides -> c.enclosing
diff --git a/core/src/main/scala/mill/main/ReplApplyHandler.scala b/core/src/main/scala/mill/main/ReplApplyHandler.scala
index 7817a77f..a2da4a2f 100644
--- a/core/src/main/scala/mill/main/ReplApplyHandler.scala
+++ b/core/src/main/scala/mill/main/ReplApplyHandler.scala
@@ -2,13 +2,17 @@ package mill.main
 
 
 import mill.define.Applicative.ApplyHandler
-import mill.define.Task
-import mill.discover.Discovered
+import mill.define.{Cross, Target, Task}
+import mill.discover.Mirror.Segment
+import mill.discover.{Discovered, Mirror}
 import mill.eval.Evaluator
 import mill.util.OSet
+
+import scala.collection.mutable
 object ReplApplyHandler{
-  def apply[T](mapping: Discovered.Mapping[T]) = {
+  def apply[T](pprinter0: pprint.PPrinter, mapping: Discovered.Mapping[T]) = {
     new ReplApplyHandler(
+      pprinter0,
       new mill.eval.Evaluator(
         ammonite.ops.pwd / 'out,
         ammonite.ops.pwd,
@@ -18,7 +22,7 @@ object ReplApplyHandler{
     )
   }
 }
-class ReplApplyHandler(evaluator: Evaluator[_]) extends ApplyHandler[Task] {
+class ReplApplyHandler(pprinter0: pprint.PPrinter, evaluator: Evaluator[_]) extends ApplyHandler[Task] {
   // Evaluate classLoaderSig only once in the REPL to avoid busting caches
   // as the user enters more REPL commands and changes the classpath
   val classLoaderSig = Evaluator.classLoaderSig
@@ -27,4 +31,53 @@ class ReplApplyHandler(evaluator: Evaluator[_]) extends ApplyHandler[Task] {
   }
 
   val generatedEval = new EvalGenerated(evaluator)
+
+  val millHandlers: PartialFunction[Any, pprint.Tree] = {
+    case c: Cross[_] =>
+      pprint.Tree.Lazy( ctx =>
+        Iterator(c.e.value, ":", c.l.value.toString) ++
+        c.items.iterator.map(x =>
+          "\n    (" + x._1.map(pprint.PPrinter.BlackWhite.apply(_)).mkString(", ") + ")"
+        )
+      )
+    case m: mill.Module if evaluator.mapping.modulesToMirrors.contains(m) =>
+      val mirror = evaluator.mapping.modulesToMirrors(m)
+      pprint.Tree.Lazy( ctx =>
+        Iterator(m.millModuleEnclosing.value, ":", m.millModuleLine.value.toString) ++
+        (if (mirror.children.isEmpty) Nil
+        else ctx.applyPrefixColor("\nChildren:").toString +: mirror.children.map("\n    ." + _._1)) ++
+        (if (mirror.commands.isEmpty) Nil
+        else ctx.applyPrefixColor("\nCommands:").toString +: mirror.commands.sortBy(_.name).map{c =>
+          "\n    ." + c.name + "(" +
+            c.argSignatures.map(s => s.name + ": " + s.typeString).mkString(", ") +
+            ")()"
+        }) ++
+        (if (mirror.targets.isEmpty) Nil
+        else ctx.applyPrefixColor("\nTargets:").toString +: mirror.targets.sortBy(_.label).map(t =>
+          "\n    ." + t.label + "()"
+        ))
+
+      )
+    case t: mill.define.Target[_] if evaluator.mapping.targetsToSegments.contains(t) =>
+      val seen = mutable.Set.empty[Task[_]]
+      def rec(t: Task[_]): Seq[Seq[Segment]] = {
+        if (seen(t)) Nil // do nothing
+        else t match {
+          case t: Target[_] if evaluator.mapping.targetsToSegments.contains(t) =>
+            Seq(evaluator.mapping.targetsToSegments(t))
+          case _ =>
+            seen.add(t)
+            t.inputs.flatMap(rec)
+        }
+      }
+      pprint.Tree.Lazy(ctx =>
+        Iterator(t.enclosing, ":", t.lineNum.toString, "\n", ctx.applyPrefixColor("Inputs:").toString) ++
+        t.inputs.iterator.flatMap(rec).map("\n    " + Mirror.renderSelector(_))
+      )
+
+  }
+  ammonite.main.Cli
+  val pprinter = pprinter0.copy(
+    additionalHandlers = millHandlers orElse pprinter0.additionalHandlers
+  )
 }
diff --git a/core/src/main/scala/mill/main/RunScript.scala b/core/src/main/scala/mill/main/RunScript.scala
index f5523bb6..e2c8ce6c 100644
--- a/core/src/main/scala/mill/main/RunScript.scala
+++ b/core/src/main/scala/mill/main/RunScript.scala
@@ -163,7 +163,7 @@ object RunScript{
         val json = for(t <- Seq(target)) yield {
           t match {
             case t: mill.define.NamedTask[_] =>
-              for (segments <- evaluator.mapping.modules.get(t.owner)) yield {
+              for (segments <- evaluator.mapping.modulesToPaths.get(t.owner)) yield {
                 val jsonFile = Evaluator.resolveDestPaths(evaluator.workspacePath, segments :+ Segment.Label(t.name)).meta
                 val metadata = upickle.json.read(jsonFile.toIO)
                 metadata(1)
diff --git a/core/src/test/scala/mill/define/GraphTests.scala b/core/src/test/scala/mill/define/GraphTests.scala
index d17f125f..a850a0d2 100644
--- a/core/src/test/scala/mill/define/GraphTests.scala
+++ b/core/src/test/scala/mill/define/GraphTests.scala
@@ -157,7 +157,7 @@ object GraphTests extends TestSuite{
           Graph.transitiveTargets(OSet.from(goals))
         )
         val grouped = Graph.groupAroundImportantTargets(topoSorted) {
-          case t: NamedTask[Any] if mapping.modules.contains(t.owner) => t
+          case t: NamedTask[Any] if mapping.modulesToPaths.contains(t.owner) => t
           case t if goals.contains(t) => t
         }
         grouped.keyCount
diff --git a/core/src/test/scala/mill/discover/CrossModuleTests.scala b/core/src/test/scala/mill/discover/CrossModuleTests.scala
index 99d33800..e0a7a1a0 100644
--- a/core/src/test/scala/mill/discover/CrossModuleTests.scala
+++ b/core/src/test/scala/mill/discover/CrossModuleTests.scala
@@ -77,14 +77,14 @@ object CrossModuleTests extends TestSuite{
 
       val discovered = Discovered.mapping(singleCross)
 
-      val segments = discovered.targets.values.toSet
+      val segments = discovered.targetsToSegments.values.toSet
       val expectedSegments = Set(
         List(Label("cross"), Segment.Cross(List("210")), Label("suffix")),
         List(Label("cross"), Segment.Cross(List("211")), Label("suffix")),
         List(Label("cross"), Segment.Cross(List("212")), Label("suffix"))
       )
       assert(segments == expectedSegments)
-      val targets = discovered.targets.keys.toSet
+      val targets = discovered.targetsToSegments.keys.toSet
       val expected = Set(
         singleCross.cross("210").suffix,
         singleCross.cross("211").suffix,
@@ -95,7 +95,7 @@ object CrossModuleTests extends TestSuite{
 
     'doubleCrossTargetDiscovery - {
       val discovered = Discovered.mapping(doubleCross)
-      val targets = discovered.targets.keys.toSet
+      val targets = discovered.targetsToSegments.keys.toSet
 
       val expected = Set(
         doubleCross.cross("jvm", "210").suffix,
@@ -110,7 +110,7 @@ object CrossModuleTests extends TestSuite{
     }
 
     'nestedCrosses - {
-      val discovered = Discovered.mapping(nestedCrosses).targets
+      val discovered = Discovered.mapping(nestedCrosses).targetsToSegments
       assert(discovered.size == 9)
     }
   }
diff --git a/core/src/test/scala/mill/discover/DiscoveredTests.scala b/core/src/test/scala/mill/discover/DiscoveredTests.scala
index 8501f4cc..1a22e901 100644
--- a/core/src/test/scala/mill/discover/DiscoveredTests.scala
+++ b/core/src/test/scala/mill/discover/DiscoveredTests.scala
@@ -26,7 +26,7 @@ object DiscoveredTests extends TestSuite{
       )
       assert(flattenedHierarchy == expectedHierarchy)
 
-      val mapped = discovered.targets.map(_.swap)
+      val mapped = discovered.targetsToSegments.map(_.swap)
 
       val expected = Seq(
         (List(Label("classInstance"), Label("single")), nestedModule.classInstance.single),
@@ -38,7 +38,7 @@ object DiscoveredTests extends TestSuite{
 
     'traitWithModule - {
       val discovered = Discovered.mapping(TraitWithModuleObject)
-      val mapped = discovered.targets.map(_.swap)
+      val mapped = discovered.targetsToSegments.map(_.swap)
       val expected = Map(
         (
           List(Label("TraitModule"), Label("testFramework")),
diff --git a/core/src/test/scala/mill/discover/LabelingTests.scala b/core/src/test/scala/mill/discover/LabelingTests.scala
index 71c6a6bf..595d3ad9 100644
--- a/core/src/test/scala/mill/discover/LabelingTests.scala
+++ b/core/src/test/scala/mill/discover/LabelingTests.scala
@@ -16,7 +16,7 @@ object LabelingTests extends TestSuite{
       def check(mapping: Discovered.Mapping[_], t: Task[_], relPath: Option[String]) = {
 
 
-        val names: Seq[(Task[_], Seq[Mirror.Segment])] = mapping.targets.toSeq
+        val names: Seq[(Task[_], Seq[Mirror.Segment])] = mapping.targetsToSegments.toSeq
         val nameMap = names.toMap
 
         val targetLabel = nameMap.get(t).map(_.map{case Label(v) => v}.mkString("."))
diff --git a/core/src/test/scala/mill/eval/JavaCompileJarTests.scala b/core/src/test/scala/mill/eval/JavaCompileJarTests.scala
index 5ddbb68e..ca317a06 100644
--- a/core/src/test/scala/mill/eval/JavaCompileJarTests.scala
+++ b/core/src/test/scala/mill/eval/JavaCompileJarTests.scala
@@ -58,7 +58,7 @@ object JavaCompileJarTests extends TestSuite{
           Right(Tuple2(
             evaluated.rawValues(0).asInstanceOf[Result.Success[T]].value,
             evaluated.evaluated.collect{
-              case t: Target[_] if mapping.targets.contains(t) => t
+              case t: Target[_] if mapping.targetsToSegments.contains(t) => t
               case t: mill.define.Command[_] => t
             }.size
           ))
@@ -73,7 +73,7 @@ object JavaCompileJarTests extends TestSuite{
         val evaluated = evaluator.evaluate(targets)
           .evaluated
           .flatMap(_.asTarget)
-          .filter(mapping.targets.contains)
+          .filter(mapping.targetsToSegments.contains)
           .filter(!_.isInstanceOf[Input[_]])
         assert(evaluated == expected)
       }
diff --git a/core/src/test/scala/mill/util/TestEvaluator.scala b/core/src/test/scala/mill/util/TestEvaluator.scala
index 646ca418..f18cfabf 100644
--- a/core/src/test/scala/mill/util/TestEvaluator.scala
+++ b/core/src/test/scala/mill/util/TestEvaluator.scala
@@ -18,7 +18,7 @@ class TestEvaluator(mapping: Discovered.Mapping[_],
         Tuple2(
           evaluated.rawValues.head.asInstanceOf[Result.Success[T]].value,
           evaluated.evaluated.collect {
-            case t: Target[_] if mapping.targets.contains(t) && !t.isInstanceOf[Input[_]] => t
+            case t: Target[_] if mapping.targetsToSegments.contains(t) && !t.isInstanceOf[Input[_]] => t
             case t: mill.define.Command[_]           => t
           }.size
         ))
diff --git a/core/src/test/scala/mill/util/TestGraphs.scala b/core/src/test/scala/mill/util/TestGraphs.scala
index 0f2c769f..25c806fa 100644
--- a/core/src/test/scala/mill/util/TestGraphs.scala
+++ b/core/src/test/scala/mill/util/TestGraphs.scala
@@ -92,7 +92,10 @@ class TestGraphs(){
     val e = {
       val c = test.anon(a)
       val d = test.anon(a)
-      test(test.anon(test.anon(), test.anon(c)), test.anon(test.anon(c, test.anon(d, b))))
+      test(
+        test.anon(test.anon(), test.anon(c)),
+        test.anon(test.anon(c, test.anon(d, b)))
+      )
     }
     val f = test(test.anon(test.anon(), test.anon(e)))
 
diff --git a/core/src/test/scala/mill/util/TestUtil.scala b/core/src/test/scala/mill/util/TestUtil.scala
index b1e37481..0d28fcf6 100644
--- a/core/src/test/scala/mill/util/TestUtil.scala
+++ b/core/src/test/scala/mill/util/TestUtil.scala
@@ -36,14 +36,16 @@ object TestUtil {
     * test how changes propagate.
     */
   class TestTarget(inputs: Seq[Task[Int]],
-             val pure: Boolean)
-            (implicit enclosing0: sourcecode.Enclosing,
-             owner0: Caller[mill.Module],
-             name0: sourcecode.Name,
-             o: Overrides)
+                   val pure: Boolean)
+                  (implicit enclosing0: sourcecode.Enclosing,
+                   lineNum0: sourcecode.Line,
+                   owner0: Caller[mill.Module],
+                   name0: sourcecode.Name,
+                   o: Overrides)
     extends Test(inputs) with Target[Int]{
     val overrides = o.value
     val enclosing = enclosing0.value
+    val lineNum = lineNum0.value
     val owner = owner0.value
     val name = name0.value
     val readWrite = upickle.default.IntRW
diff --git a/scalalib/src/main/scala/mill/scalalib/GenIdea.scala b/scalalib/src/main/scala/mill/scalalib/GenIdea.scala
index 99d8a9ad..cb059def 100644
--- a/scalalib/src/main/scala/mill/scalalib/GenIdea.scala
+++ b/scalalib/src/main/scala/mill/scalalib/GenIdea.scala
@@ -79,7 +79,7 @@ object GenIdea {
 
       val paths = Evaluator.resolveDestPaths(
         evaluator.workspacePath,
-        evaluator.mapping.modules(mod.compile)
+        evaluator.mapping.modulesToPaths(mod.compile)
       )
 
       val elem = moduleXmlTemplate(
diff --git a/scalalib/src/test/scala/mill/scalalib/HelloWorldTests.scala b/scalalib/src/test/scala/mill/scalalib/HelloWorldTests.scala
index eb883469..4cd1d58d 100644
--- a/scalalib/src/test/scala/mill/scalalib/HelloWorldTests.scala
+++ b/scalalib/src/test/scala/mill/scalalib/HelloWorldTests.scala
@@ -176,7 +176,7 @@ object HelloWorldTests extends TestSuite {
 
         val paths = Evaluator.resolveDestPaths(
           outPath,
-          helloWorldEvaluator.evaluator.mapping.targets(HelloWorld.compile)
+          helloWorldEvaluator.evaluator.mapping.targetsToSegments(HelloWorld.compile)
         )
 
         assert(