Added version settings -migration, -source

4 files changed, 199 insertions, 1 deletions

diff --git a/src/dotty/tools/dotc/config/ScalaSettings.scala b/src/dotty/tools/dotc/config/ScalaSettings.scala
index aab2942bd..af2e42b77 100644
--- a/src/dotty/tools/dotc/config/ScalaSettings.scala
+++ b/src/dotty/tools/dotc/config/ScalaSettings.scala
@@ -66,7 +66,8 @@ class ScalaSettings extends Settings.SettingGroup {
   val logFreeTerms = BooleanSetting("-Xlog-free-terms", "Print a message when reification creates a free term.")
   val logFreeTypes = BooleanSetting("-Xlog-free-types", "Print a message when reification resorts to generating a free type.")
   val maxClassfileName = IntSetting("-Xmax-classfile-name", "Maximum filename length for generated classes", 255, 72 to 255)
-  val Xmigration28 = BooleanSetting("-Xmigration", "Warn about constructs whose behavior may have changed between 2.7 and 2.8.")
+  val Xmigration = VersionSetting("-Xmigration", "Warn about constructs whose behavior may have changed since version.")
+  val Xsource = VersionSetting("-Xsource", "Treat compiler input as Scala source for the specified version.")
   val Xnojline = BooleanSetting("-Xnojline", "Do not use JLine for editing.")
   val Xverify = BooleanSetting("-Xverify", "Verify generic signatures in generated bytecode (asm backend only.)")
   val plugin = MultiStringSetting("-Xplugin", "file", "Load one or more plugins from files.")
diff --git a/src/dotty/tools/dotc/config/ScalaVersion.scala b/src/dotty/tools/dotc/config/ScalaVersion.scala
new file mode 100644
index 000000000..7d4585441
--- /dev/null
+++ b/src/dotty/tools/dotc/config/ScalaVersion.scala
@@ -0,0 +1,183 @@
+/* @author  James Iry
+ */
+package dotty.tools.dotc.config
+
+import scala.util.{Try, Success, Failure}
+
+/**
+ * Represents a single Scala version in a manner that
+ * supports easy comparison and sorting.
+ */
+sealed abstract class ScalaVersion extends Ordered[ScalaVersion] {
+  def unparse: String
+}
+
+/**
+ * A scala version that sorts higher than all actual versions
+ */
+case object NoScalaVersion extends ScalaVersion {
+  def unparse = "none"
+
+  def compare(that: ScalaVersion): Int = that match {
+    case NoScalaVersion => 0
+    case _ => 1
+  }
+}
+
+/**
+ * A specific Scala version, not one of the magic min/max versions. An SpecificScalaVersion
+ * may or may not be a released version - i.e. this same class is used to represent
+ * final, release candidate, milestone, and development builds. The build argument is used
+ * to segregate builds
+ */
+case class SpecificScalaVersion(major: Int, minor: Int, rev: Int, build: ScalaBuild) extends ScalaVersion {
+  def unparse = s"${major}.${minor}.${rev}.${build.unparse}"
+
+  def compare(that: ScalaVersion): Int =  that match {
+    case SpecificScalaVersion(thatMajor, thatMinor, thatRev, thatBuild) =>
+      // this could be done more cleanly by importing scala.math.Ordering.Implicits, but we have to do these
+      // comparisons a lot so I'm using brute force direct style code
+      if (major < thatMajor) -1
+      else if (major > thatMajor) 1
+      else if (minor < thatMinor) -1
+      else if (minor > thatMinor) 1
+      else if (rev < thatRev) -1
+      else if (rev > thatRev) 1
+      else build compare thatBuild
+    case AnyScalaVersion => 1
+    case NoScalaVersion => -1
+  }
+}
+
+/**
+ * A Scala version that sorts lower than all actual versions
+ */
+case object AnyScalaVersion extends ScalaVersion {
+  def unparse = "any"
+
+  def compare(that: ScalaVersion): Int = that match {
+    case AnyScalaVersion => 0
+    case _ => -1
+  }
+}
+
+/**
+ * Methods for parsing ScalaVersions
+ */
+object ScalaVersion {
+  private val dot = "\\."
+  private val dash = "\\-"
+  private def not(s:String) = s"[^${s}]"
+  private val R = s"((${not(dot)}*)(${dot}(${not(dot)}*)(${dot}(${not(dash)}*)(${dash}(.*))?)?)?)".r
+
+  def parse(versionString : String): Try[ScalaVersion] = {
+    def failure = Failure(new NumberFormatException(
+      s"There was a problem parsing ${versionString}. " +
+       "Versions should be in the form major[.minor[.revision]] " +
+       "where each part is a positive number, as in 2.10.1. " +
+       "The minor and revision parts are optional."
+    ))
+
+    def toInt(s: String) = s match {
+      case null | "" => 0
+      case _ => s.toInt
+    }
+
+    def isInt(s: String) = Try(toInt(s)).isSuccess
+
+    import ScalaBuild._
+
+    def toBuild(s: String) = s match {
+      case null | "FINAL" => Final
+      case s if (s.toUpperCase.startsWith("RC") && isInt(s.substring(2))) => RC(toInt(s.substring(2)))
+      case s if (s.toUpperCase.startsWith("M") && isInt(s.substring(1))) => Milestone(toInt(s.substring(1)))
+      case _ => Development(s)
+    }
+
+    try versionString match {
+      case "" | "any" => Success(AnyScalaVersion)
+      case "none" => Success(NoScalaVersion)
+      case R(_, majorS, _, minorS, _, revS, _, buildS) =>
+        Success(SpecificScalaVersion(toInt(majorS), toInt(minorS), toInt(revS), toBuild(buildS)))
+      case _ => failure
+    } catch {
+      case e: NumberFormatException => failure
+    }
+  }
+
+  /**
+   * The version of the compiler running now
+   */
+  val current = parse(util.Properties.versionNumberString).get
+}
+
+/**
+ * Represents the data after the dash in major.minor.rev-build
+ */
+abstract class ScalaBuild extends Ordered[ScalaBuild] {
+  /**
+   * Return a version of this build information that can be parsed back into the
+   * same ScalaBuild
+   */
+  def unparse: String
+}
+
+object ScalaBuild {
+
+  /** A development, test, nightly, snapshot or other "unofficial" build
+   */
+  case class Development(id: String) extends ScalaBuild {
+    def unparse = s"-${id}"
+
+    def compare(that: ScalaBuild) = that match {
+      // sorting two development builds based on id is reasonably valid for two versions created with the same schema
+      // otherwise it's not correct, but since it's impossible to put a total ordering on development build versions
+      // this is a pragmatic compromise
+      case Development(thatId) => id compare thatId
+      // assume a development build is newer than anything else, that's not really true, but good luck
+      // mapping development build versions to other build types
+      case _ => 1
+    }
+  }
+
+  /** A final build
+   */
+  case object Final extends ScalaBuild {
+    def unparse = ""
+
+    def compare(that: ScalaBuild) = that match {
+      case Final => 0
+      // a final is newer than anything other than a development build or another final
+      case Development(_) => -1
+      case _ => 1
+    }
+  }
+
+  /** A candidate for final release
+   */
+  case class RC(n: Int) extends ScalaBuild {
+    def unparse = s"-RC${n}"
+
+    def compare(that: ScalaBuild) = that match {
+      // compare two rcs based on their RC numbers
+      case RC(thatN) => n - thatN
+      // an rc is older than anything other than a milestone or another rc
+      case Milestone(_) => 1
+      case _ => -1
+    }
+  }
+
+  /** An intermediate release
+   */
+  case class Milestone(n: Int) extends ScalaBuild {
+    def unparse = s"-M${n}"
+
+    def compare(that: ScalaBuild) = that match {
+      // compare two milestones based on their milestone numbers
+      case Milestone(thatN) => n - thatN
+      // a milestone is older than anything other than another milestone
+      case _ => -1
+
+    }
+  }
+}
diff --git a/src/dotty/tools/dotc/config/Settings.scala b/src/dotty/tools/dotc/config/Settings.scala
index 17d4d6712..531c49bfb 100644
--- a/src/dotty/tools/dotc/config/Settings.scala
+++ b/src/dotty/tools/dotc/config/Settings.scala
@@ -18,6 +18,7 @@ object Settings {
   val IntTag = ClassTag.Int
   val StringTag = ClassTag(classOf[String])
   val ListTag = ClassTag(classOf[List[_]])
+  val VersionTag = ClassTag(classOf[ScalaVersion])
 
   class SettingsState(initialValues: Seq[Any]) {
     private var values = ArrayBuffer(initialValues: _*)
@@ -132,6 +133,11 @@ object Settings {
             case _: NumberFormatException =>
               fail(s"$arg2 is not an integer argument for $name", args2)
           }
+        case (VersionTag, _) =>
+          ScalaVersion.parse(argRest) match {
+            case Success(v) => update(v, args)
+            case Failure(ex) => fail(ex.getMessage, args)
+          }
         case (_, Nil) =>
           missingArg
       }
@@ -246,5 +252,8 @@ object Settings {
 
     def PrefixSetting(name: String, pre: String, descr: String): Setting[List[String]] =
       publish(Setting(name, descr, Nil, prefix = pre))
+
+    def VersionSetting(name: String, descr: String, default: ScalaVersion = NoScalaVersion): Setting[ScalaVersion] =
+      publish(Setting(name, descr, default))
   }
 }
\ No newline at end of file
diff --git a/src/dotty/tools/dotc/core/Definitions.scala b/src/dotty/tools/dotc/core/Definitions.scala
index 286d1437f..f20882ce4 100644
--- a/src/dotty/tools/dotc/core/Definitions.scala
+++ b/src/dotty/tools/dotc/core/Definitions.scala
@@ -107,6 +107,10 @@ class Definitions {
   lazy val JavaPackageVal = ctx.requiredPackage("java")
   lazy val JavaLangPackageVal = ctx.requiredPackage("java.lang")
 
+  // fundamental modules
+  lazy val SysPackage = ctx.requiredModule("scala.sys.package")
+    def Sys_error = ctx.requiredMethod(SysPackage.moduleClass.asClass, nme.error)
+
   /** Note: We cannot have same named methods defined in Object and Any (and AnyVal, for that matter)
    *  because after erasure the Any and AnyVal references get remapped to the Object methods
    *  which would result in a double binding assertion failure.
@@ -292,6 +296,7 @@ class Definitions {
   lazy val ScalaSignatureAnnot = ctx.requiredClass("scala.reflect.ScalaSignature")
   lazy val ScalaLongSignatureAnnot = ctx.requiredClass("scala.reflect.ScalaLongSignature")
   lazy val DeprecatedAnnot = ctx.requiredClass("scala.deprecated")
+  lazy val MigrationAnnot = ctx.requiredClass("scala.migration")
   lazy val AnnotationDefaultAnnot = ctx.requiredClass("dotty.annotation.internal.AnnotationDefault")
   lazy val ThrowsAnnot = ctx.requiredClass("scala.throws")
   lazy val UncheckedAnnot = ctx.requiredClass("scala.unchecked")