Use sbt for PR validation

- Support directories in `-doc-external-doc`: It is documented as
  accepting a “classpath_entry_path” for the keys but this only worked
  for JARs and not for individual class files. When checking for
  external-doc mappings for a Symbol, we now find the root directory
  relative to a class file instead of using the full class file path.
  The corresponding tests for SI-191 and SI8557 are also fixed to
  support individual class files instead of JARs in partest. This is
  required for the sbt build which runs partest on “quick” instead of
  “pack”.

- Fix version and repository handling for bootstrapping. The bootstrap
  `scalaInstance` can now be resolved from any repository added to the
  project (not just the bootstrap repositories) by using a different
  workaround for https://github.com/sbt/sbt/issues/1872.

- Workaround for https://github.com/sbt/sbt/issues/2640 (putting the
  wrong `scalaInstance` on partest’s classpath). The required
  `ScalaInstance` constructor is deprecated, so we have to disable
  deprecation warnings and fatal warnings until there is a better fix.

- Add MiMa to the sbt build (port of the old `test.bc` ant task). The
  sbt-mima plugin doesn’t have all the features we need, so we do it
  manually in a similar way to what the plugin does. Checks are done
  in both directions for the `library` and `compiler` projects. The
  base version has to be set in `build.sbt`. When set to `None`, MiMa
  checks are skipped. MiMa checks are run sequentially to avoid spurious
  errors (see https://github.com/typesafehub/migration-manager/issues/115).

- Port the OSGi tests to the sbt build. The set of JARs that gets copied
  into build/osgi as bundles is a bit different from the ant build. We
  omit the source JARs but add additional modules that are part of the
  Scala distribution, which seems more correct.

- Get rid up `pull-binary-libs.sh` for the sbt build. Add artifacts are
  resolved from the special bootstrap repository through Ivy. The
  special `code.jar` and `instrumented.jar` artifacts are copied to the
  location where partest expects them (because these paths are hardcoded
  in partest). Other extra JARs for partest in `test/files/lib` are
  referenced directly from the Ivy cache.

- Move common settings that should be available with unqualified names
  in local `.sbt` files and on the command line into an auto-plugin.

- Add an `antStyle` setting to sbt to allow users to easily enable
  ant-style incremental compilation instead of sbt’s standard name
  hashing with `set antStyle := true`.

- Disable verbose `info`-level logging during sbt startup for both,
  `validate/test` and `validate/publish-core` jobs. Update logging is
  no longer disabled when running locally (where it is useful and
  doesn’t generate excessive output).

- Pass optimization flags for scalac down to partest, using the new
  partest version 1.0.15\6.

- Call the new sbt-based PR validation from `scripts/jobs/validate/test`.

- Disable the tests `run/t7843-jsr223-service` and `run/t7933` from
  https://github.com/scala/scala/pull/4959 for now. We need to set up
  a new test project (either partest or junit) that can run them on a
  packaged version of Scala, or possibly move them into a separate
  project that would naturally run from a packaged Scala as part of the
  community build.

8 files changed, 167 insertions, 17 deletions

diff --git a/project/BuildSettings.scala b/project/BuildSettings.scala
new file mode 100644
index 0000000000..76cd888a2d
--- /dev/null
+++ b/project/BuildSettings.scala
@@ -0,0 +1,11 @@
+import sbt._
+
+/** This object defines keys that should be visible with an unqualified name in all .sbt files and the command line */
+object BuildSettings extends AutoPlugin {
+  object autoImport {
+    lazy val antStyle = settingKey[Boolean]("Use ant-style incremental builds instead of name-hashing")
+    lazy val baseVersion = settingKey[String]("The base version number from which all others are derived")
+    lazy val baseVersionSuffix = settingKey[String]("Identifies the kind of version to build")
+    lazy val mimaReferenceVersion = settingKey[Option[String]]("Scala version number to run MiMa against")
+  }
+}
diff --git a/project/MiMa.scala b/project/MiMa.scala
new file mode 100644
index 0000000000..66442fc725
--- /dev/null
+++ b/project/MiMa.scala
@@ -0,0 +1,95 @@
+// It would be nice to use sbt-mima-plugin here, but the plugin is missing
+// at least two features we need:
+// * ability to run MiMa twice, swapping `curr` and `prev`, to detect
+//   both forwards and backwards incompatibilities (possibly fixed as of
+//   https://github.com/typesafehub/migration-manager/commit/2844ffa48b6d2255aa64bd687703aec21dadd55e)
+// * ability to pass a filter file (https://github.com/typesafehub/migration-manager/issues/102)
+// So we invoke the MiMa CLI directly; it's also what the Ant build did.
+
+import sbt._
+import sbt.Keys._
+import BuildSettings.autoImport._
+
+object MiMa {
+  lazy val mima =
+    taskKey[Unit]("run Migration Manager to detect binary incompatibilities")
+
+  lazy val settings =
+    Seq(
+      mima := {
+        val log = streams.value.log
+        mimaReferenceVersion.value.fold {
+          log.info(s"No reference version defined - skipping binary compatibility checks")
+        } { refVersion =>
+          def runOnce(prev: java.io.File, curr: java.io.File, isForward: Boolean): Unit = {
+            val direction = if (isForward) "forward" else "backward"
+            log.info(s"Checking $direction binary compatibility")
+            log.debug(s"prev = $prev, curr = $curr")
+            runMima(
+              prev = if (isForward) curr else prev,
+              curr = if (isForward) prev else curr,
+              // TODO: it would be nicer if each subproject had its own whitelist, but for now
+              // for compatibility with how Ant did things, there's just one at the root.
+              // once Ant is gone we'd be free to split it up.
+              filter = (baseDirectory in ThisBuild).value / s"bincompat-$direction.whitelist.conf",
+              log)
+          }
+          val artifact =
+            getPreviousArtifact(
+              "org.scala-lang" % s"${name.value}" % refVersion,
+              ivySbt.value, streams.value)
+          for (isForward <- Seq(false, true))
+            runOnce(artifact, (packageBin in Compile).value, isForward)
+        }
+      }
+    )
+
+  def runMima(prev: java.io.File, curr: java.io.File, filter: java.io.File, log: Logger): Unit = {
+    val args = Array(
+      "--prev", prev.getAbsolutePath,
+      "--curr", curr.getAbsolutePath,
+      "--filters", filter.getAbsolutePath,
+      "--generate-filters"
+    )
+    val exitCode = TrapExit(com.typesafe.tools.mima.cli.Main.main(args), log)
+    if (exitCode != 0)
+      throw new RuntimeException(s"MiMa failed with exit code $exitCode")
+  }
+
+  // cribbed from https://github.com/typesafehub/migration-manager/blob/master/sbtplugin/src/main/scala/com/typesafe/tools/mima/plugin/SbtMima.scala
+  def getPreviousArtifact(m: ModuleID, ivy: IvySbt, s: TaskStreams): File = {
+    val moduleSettings = InlineConfiguration(
+      "dummy" % "test" % "version",
+      ModuleInfo("dummy-test-project-for-resolving"),
+      dependencies = Seq(m))
+    val module = new ivy.Module(moduleSettings)
+    val report = Deprecated.Inner.ivyUpdate(ivy)(module, s)
+    val optFile = (for {
+      config <- report.configurations
+      module <- config.modules
+      (artifact, file) <- module.artifacts
+      // TODO - Hardcode this?
+      if artifact.name == m.name
+    } yield file).headOption
+    optFile getOrElse sys.error("Could not resolve previous artifact: " + m)
+  }
+
+}
+
+// use the SI-7934 workaround to silence a deprecation warning on an sbt API
+// we have no choice but to call.  on the lack of any suitable alternative,
+// see https://gitter.im/sbt/sbt-dev?at=5616e2681b0e279854bd74a4 :
+// "it's my intention to eventually come up with a public API" says Eugene Y
+object Deprecated {
+  @deprecated("", "") class Inner {
+    def ivyUpdate(ivy: IvySbt)(module: ivy.Module, s: TaskStreams) =
+      IvyActions.update(
+        module,
+        new UpdateConfiguration(
+          retrieve = None,
+          missingOk = false,
+          logging = UpdateLogging.DownloadOnly),
+        s.log)
+  }
+  object Inner extends Inner
+}
diff --git a/project/Osgi.scala b/project/Osgi.scala
index d780be2f78..b557df1688 100644
--- a/project/Osgi.scala
+++ b/project/Osgi.scala
@@ -28,8 +28,8 @@ object Osgi {
         "Bundle-Name" -> bundleName.value,
         "Bundle-SymbolicName" -> bundleSymbolicName.value,
         "ver" -> v,
-        "Export-Package" -> ("*;version=${ver}"),
-        "Import-Package" -> ("scala.*;version=\"${range;[==,=+);${ver}}\",*"),
+        "Export-Package" -> "*;version=${ver}",
+        "Import-Package" -> "scala.*;version=\"${range;[==,=+);${ver}}\",*",
         "Bundle-Version" -> v,
         "Bundle-RequiredExecutionEnvironment" -> "JavaSE-1.6, JavaSE-1.7",
         "-eclipse" -> "false"
diff --git a/project/Quiet.scala b/project/Quiet.scala
index de30ebe6ab..84d01d5544 100644
--- a/project/Quiet.scala
+++ b/project/Quiet.scala
@@ -28,6 +28,4 @@ object Quiet {
       case x => x
     }
   }
-
-  def silenceIvyUpdateInfoLogging = logLevel in update := Level.Warn
 }
diff --git a/project/ScalaTool.scala b/project/ScalaTool.scala
index e9531f229e..5e3f20b1ba 100644
--- a/project/ScalaTool.scala
+++ b/project/ScalaTool.scala
@@ -27,12 +27,12 @@ case class ScalaTool(mainClass: String,
       } else classpath.mkString(":").replace('\\', '/').replaceAll(varRegex, """\${$1}""")
 
     val variables = Map(
-      ("@@"           -> "@"), // for backwards compatibility
-      ("@class@"      -> mainClass),
-      ("@properties@" -> (properties map { case (k, v) => s"""-D$k="$v""""} mkString " ")),
-      ("@javaflags@"  -> javaOpts),
-      ("@toolflags@"  -> toolFlags),
-      ("@classpath@"  -> platformClasspath)
+      "@@"           -> "@", // for backwards compatibility
+      "@class@"      -> mainClass,
+      "@properties@" -> (properties map { case (k, v) => s"""-D$k="$v""""} mkString " "),
+      "@javaflags@"  -> javaOpts,
+      "@toolflags@"  -> toolFlags,
+      "@classpath@"  -> platformClasspath
     )
 
     val (from, to) = variables.unzip
diff --git a/project/ScriptCommands.scala b/project/ScriptCommands.scala
index 537990d985..efeac95e6d 100644
--- a/project/ScriptCommands.scala
+++ b/project/ScriptCommands.scala
@@ -1,19 +1,32 @@
 import sbt._
 import Keys._
-import complete.DefaultParsers._
+import BuildSettings.autoImport._
 
 /** Custom commands for use by the Jenkins scripts. This keeps the surface area and call syntax small. */
 object ScriptCommands {
-  def all = Seq(setupPublishCore)
+  def all = Seq(setupPublishCore, setupValidateTest)
 
   /** Set up the environment for `validate/publish-core`. The argument is the Artifactory snapshot repository URL. */
   def setupPublishCore = Command.single("setupPublishCore") { case (state, url) =>
       Project.extract(state).append(Seq(
-        VersionUtil.baseVersionSuffix in Global := "SHA-SNAPSHOT",
+        baseVersionSuffix in Global := "SHA-SNAPSHOT",
         // Append build.timestamp to Artifactory URL to get consistent build numbers (see https://github.com/sbt/sbt/issues/2088):
         publishTo in Global := Some("scala-pr" at url.replaceAll("/$", "") + ";build.timestamp=" + System.currentTimeMillis),
         publishArtifact in (Compile, packageDoc) in ThisBuild := false,
-        scalacOptions in Compile in ThisBuild += "-optimise"
+        scalacOptions in Compile in ThisBuild += "-optimise",
+        logLevel in ThisBuild := Level.Info,
+        logLevel in update in ThisBuild := Level.Warn
       ), state)
     }
+
+  /** Set up the environment for `validate/test`. The argument is the Artifactory snapshot repository URL. */
+  def setupValidateTest = Command.single("setupValidateTest") { case (state, url) =>
+    //TODO When ant is gone, pass starr version as an argument to this command instead of using version.properties
+    Project.extract(state).append(Seq(
+      resolvers in Global += "scala-pr" at url,
+      scalacOptions in Compile in ThisBuild += "-optimise",
+      logLevel in ThisBuild := Level.Info,
+      logLevel in update in ThisBuild := Level.Warn
+    ), state)
+  }
 }
diff --git a/project/VersionUtil.scala b/project/VersionUtil.scala
index 6c8aebf74f..4705bbb6ce 100644
--- a/project/VersionUtil.scala
+++ b/project/VersionUtil.scala
@@ -1,12 +1,11 @@
 import sbt._
 import Keys._
 import java.util.Properties
-import java.io.FileInputStream
+import java.io.{File, FileInputStream}
 import scala.collection.JavaConverters._
+import BuildSettings.autoImport._
 
 object VersionUtil {
-  lazy val baseVersion = settingKey[String]("The base version number from which all others are derived")
-  lazy val baseVersionSuffix = settingKey[String]("Identifies the kind of version to build")
   lazy val copyrightString = settingKey[String]("Copyright string.")
   lazy val versionProperties = settingKey[Versions]("Version properties.")
   lazy val generateVersionPropertiesFile = taskKey[File]("Generating version properties file.")
@@ -123,4 +122,33 @@ object VersionUtil {
   /** Get a subproject version number from `versionProps` */
   def versionNumber(name: String): String =
     versionProps(s"$name.version.number")
+
+  /** Build a dependency to a Scala module with the given group and artifact ID */
+  def scalaDep(group: String, artifact: String, versionProp: String = null, scope: String = null, compatibility: String = "binary") = {
+    val vp = if(versionProp eq null) artifact else versionProp
+    val m = group % (artifact + "_" + versionProps(s"scala.$compatibility.version")) % versionNumber(vp)
+    val m2 = if(scope eq null) m else m % scope
+    // exclusion of the scala-library transitive dependency avoids eviction warnings during `update`:
+    m2.exclude("org.scala-lang", "*")
+  }
+
+  private def bootstrapOrganization(path: String) =
+    "org.scala-lang.scala-sha-bootstrap." + path.replace('/', '.')
+
+  /** Build a dependency to a JAR file in the bootstrap repository */
+  def bootstrapDep(baseDir: File, path: String, libName: String): ModuleID = {
+    val sha = IO.read(baseDir / path / s"$libName.jar.desired.sha1").split(' ')(0)
+    bootstrapOrganization(path) % libName % sha from
+      s"https://dl.bintray.com/typesafe/scala-sha-bootstrap/org/scala-lang/bootstrap/$sha/$path/$libName.jar"
+  }
+
+  /** Copy a boostrap dependency JAR that is on the classpath to a file */
+  def copyBootstrapJar(cp: Seq[Attributed[File]], baseDir: File, path: String, libName: String): Unit = {
+    val org = bootstrapOrganization(path)
+    val resolved = cp.find { a =>
+      val mod = a.get(moduleID.key)
+      mod.map(_.organization) == Some(org) && mod.map(_.name) == Some(libName)
+    }.map(_.data).get
+    IO.copyFile(resolved, baseDir / path / s"$libName.jar")
+  }
 }
diff --git a/project/plugins.sbt b/project/plugins.sbt
index 46203565b4..4c0a6e7b8a 100644
--- a/project/plugins.sbt
+++ b/project/plugins.sbt
@@ -1,3 +1,6 @@
+scalacOptions ++= Seq("-unchecked", "-feature", /*"-deprecation",*/
+  "-Xlint" /*, "-Xfatal-warnings"*/)
+
 libraryDependencies += "org.apache.commons" % "commons-lang3" % "3.3.2"
 
 libraryDependencies += "org.pantsbuild" % "jarjar" % "1.6.3"
@@ -15,3 +18,5 @@ buildClasspath := (externalDependencyClasspath in Compile).value.map(_.data).mkS
 buildInfoKeys := Seq[BuildInfoKey](buildClasspath)
 
 buildInfoPackage := "scalabuild"
+
+libraryDependencies += "com.typesafe" %% "mima-reporter" % "0.1.8"