Merge pull request #2943 from eed3si9n/backport/generators

[sbt 0.13] Support sourceGenerators += Def.task { ... }

main/settings/src/main/scala/sbt/Append.scala

@@ -1,8 +1,9 @@
 package sbt
 
 import java.io.File
-import Def.Classpath
+import Def.{ Classpath, Initialize }
 import scala.annotation.implicitNotFound
+import reflect.internal.annotations.compileTimeOnly
 
 object Append {
   @implicitNotFound(msg = "No implicit for Append.Value[${A}, ${B}] found,\n  so ${B} cannot be appended to ${A}")
@@ -23,6 +24,14 @@ object Append {
     def appendValues(a: Seq[T], b: Seq[V]): Seq[T] = a ++ (b map { x => (x: T) })
     def appendValue(a: Seq[T], b: V): Seq[T] = a :+ (b: T)
   }
+  @compileTimeOnly("This can be used in += only.")
+  implicit def appendTaskValueSeq[T, V <: T]: Value[Seq[Task[T]], Initialize[Task[V]]] = new Value[Seq[Task[T]], Initialize[Task[V]]] {
+    def appendValue(a: Seq[Task[T]], b: Initialize[Task[V]]): Seq[Task[T]] = ???
+  }
+  @compileTimeOnly("This can be used in += only.")
+  implicit def appendTaskKeySeq[T, V <: T]: Value[Seq[Task[T]], TaskKey[V]] = new Value[Seq[Task[T]], TaskKey[V]] {
+    def appendValue(a: Seq[Task[T]], b: TaskKey[V]): Seq[Task[T]] = ???
+  }
   implicit def appendList[T, V <: T]: Sequence[List[T], List[V], V] = new Sequence[List[T], List[V], V] {
     def appendValues(a: List[T], b: List[V]): List[T] = a ::: b
     def appendValue(a: List[T], b: V): List[T] = a :+ b

main/settings/src/main/scala/sbt/std/TaskMacro.scala

@@ -168,9 +168,24 @@ object TaskMacro {
   /** Implementation of += macro for settings. */
   def settingAppend1Impl[T: c.WeakTypeTag, U: c.WeakTypeTag](c: Context)(v: c.Expr[U])(a: c.Expr[Append.Value[T, U]]): c.Expr[Setting[T]] =
     {
-      val init = SettingMacro.settingMacroImpl[U](c)(v)
-      val append = appendMacroImpl(c)(init.tree, a.tree)(Append1InitName)
-      c.Expr[Setting[T]](append)
+      import c.universe._
+      val util = ContextUtil[c.type](c)
+      val ttpe = c.weakTypeOf[T]
+      val typeArgs = util.typeArgs(ttpe)
+      v.tree.tpe match {
+        // To allow Initialize[Task[A]] in the position of += RHS, we're going to call "taskValue" automatically.
+        case tpe if typeArgs.nonEmpty && (tpe weak_<:< c.weakTypeOf[Initialize[_]]) =>
+          c.macroApplication match {
+            case Apply(Apply(TypeApply(Select(preT, nmeT), targs), _), _) =>
+              val tree = Apply(TypeApply(Select(preT, newTermName("+=").encodedName), TypeTree(typeArgs.head) :: Nil), Select(v.tree, newTermName("taskValue").encodedName) :: Nil)
+              c.Expr[Setting[T]](tree)
+            case x => ContextUtil.unexpectedTree(x)
+          }
+        case _ =>
+          val init = SettingMacro.settingMacroImpl[U](c)(v)
+          val append = appendMacroImpl(c)(init.tree, a.tree)(Append1InitName)
+          c.Expr[Setting[T]](append)
+      }
     }
   /** Implementation of ++= macro for tasks. */
   def taskAppendNImpl[T: c.WeakTypeTag, U: c.WeakTypeTag](c: Context)(vs: c.Expr[U])(a: c.Expr[Append.Values[T, U]]): c.Expr[Setting[Task[T]]] =
@@ -186,7 +201,6 @@ object TaskMacro {
       val append = appendMacroImpl(c)(init.tree, a.tree)(AppendNInitName)
       c.Expr[Setting[T]](append)
     }
-
   /** Implementation of -= macro for tasks. */
   def taskRemove1Impl[T: c.WeakTypeTag, U: c.WeakTypeTag](c: Context)(v: c.Expr[U])(r: c.Expr[Remove.Value[T, U]]): c.Expr[Setting[Task[T]]] =
     {
@@ -221,7 +235,7 @@ object TaskMacro {
       import c.universe.{ Apply, ApplyTag, newTermName, Select, SelectTag, TypeApply, TypeApplyTag }
       c.macroApplication match {
         case Apply(Apply(TypeApply(Select(preT, nmeT), targs), _), a) =>
-          Apply(Apply(TypeApply(Select(preT, newTermName(newName).encodedName), targs), init :: sourcePosition(c).tree :: Nil), a)
+          Apply(Apply(TypeApply(Select(preT, newTermName(newName).encodedName), targs), init :: sourcePosition(c).tree :: Nil), append :: Nil)
         case x => ContextUtil.unexpectedTree(x)
       }
     }

main/src/main/scala/sbt/Defaults.scala

@@ -208,7 +208,7 @@ object Defaults extends BuildCommon {
     unmanagedResources := collectFiles(unmanagedResourceDirectories, includeFilter in unmanagedResources, excludeFilter in unmanagedResources).value,
     watchSources in ConfigGlobal ++= unmanagedResources.value,
     resourceGenerators :== Nil,
-    resourceGenerators += ((discoveredSbtPlugins, resourceManaged) map PluginDiscovery.writeDescriptors).taskValue,
+    resourceGenerators += Def.task { PluginDiscovery.writeDescriptors(discoveredSbtPlugins.value, resourceManaged.value) },
     managedResources := generate(resourceGenerators).value,
     resources := Classpaths.concat(managedResources, unmanagedResources).value
   )

sbt/src/sbt-test/actions/generator/build.sbt

@@ -0,0 +1,13 @@
+lazy val buildInfo = taskKey[Seq[File]]("The task that generates the build info.")
+
+lazy val root = (project in file("."))
+  .settings(
+    scalaVersion := "2.11.8",
+    buildInfo := {
+      val x = sourceManaged.value / "BuildInfo.scala"
+      IO.write(x, """object BuildInfo""")
+      x :: Nil
+    },
+    sourceGenerators in Compile += buildInfo,
+    sourceGenerators in Compile += Def.task { Nil }
+  )

sbt/src/sbt-test/actions/generator/test

@@ -0,0 +1,2 @@
+> compile
+$ exists target/scala-2.11/src_managed/BuildInfo.scala

sbt/src/sbt-test/project/auto-plugins-default-requires-jvmplugin/build.sbt

@@ -1,8 +1,8 @@
 val test123 = project in file(".") enablePlugins TestP settings(
-  resourceGenerators in Compile += (Def.task {
+  resourceGenerators in Compile += Def.task {
     streams.value.log info "resource generated in settings"
     Nil
-  }).taskValue
+  }
 )
 
 TaskKey[Unit]("check") := {

util/appmacro/src/main/scala/sbt/appmacro/ContextUtil.scala

@@ -126,6 +126,9 @@ final class ContextUtil[C <: Context](val ctx: C) {
   def freshMethodParameter(tpe: Type): ValDef =
     ValDef(parameterModifiers, freshTermName("p"), TypeTree(tpe), EmptyTree)
 
+  def typeArgs(tpe: Type): List[Type] =
+    tpe.asInstanceOf[global.Type].typeArgs map { _.asInstanceOf[Type] }
+
   /** Constructs a ValDef with local modifiers and a unique name. */
   def localValDef(tpt: Tree, rhs: Tree): ValDef =
     ValDef(localModifiers, freshTermName("q"), tpt, rhs)