1 files changed, 103 insertions, 0 deletions
diff --git a/project/VersionUtil.scala b/project/VersionUtil.scala
new file mode 100644
index 0000000000..71de772b08
--- /dev/null
+++ b/project/VersionUtil.scala
@@ -0,0 +1,103 @@
+import sbt._
+import Keys._
+import java.util.Properties
+import java.io.FileInputStream
+import scala.collection.JavaConverters._
+
+object VersionUtil {
+  lazy val copyrightString = settingKey[String]("Copyright string.")
+  lazy val versionProperties = settingKey[Versions]("Version properties.")
+  lazy val generateVersionPropertiesFile = taskKey[File]("Generating version properties file.")
+
+  lazy val versionPropertiesSettings = Seq[Setting[_]](
+    versionProperties := versionPropertiesImpl.value
+  )
+
+  lazy val generatePropertiesFileSettings = Seq[Setting[_]](
+    copyrightString := "Copyright 2002-2015, LAMP/EPFL",
+    resourceGenerators in Compile += generateVersionPropertiesFile.map(file => Seq(file)).taskValue,
+    versionProperties := versionPropertiesImpl.value,
+    generateVersionPropertiesFile := generateVersionPropertiesFileImpl.value
+  )
+
+  case class Versions(canonicalVersion: String, mavenVersion: String, osgiVersion: String, commitSha: String, commitDate: String, isRelease: Boolean) {
+    val githubTree =
+      if(isRelease) "v" + mavenVersion
+      else if(commitSha != "unknown") commitSha
+      else "master"
+
+    override def toString = s"Canonical: $canonicalVersion, Maven: $mavenVersion, OSGi: $osgiVersion, github: $githubTree"
+
+    def toProperties: Properties = {
+      val props = new Properties
+      props.put("version.number", canonicalVersion)
+      props.put("maven.version.number", mavenVersion)
+      props.put("osgi.version.number", osgiVersion)
+      props
+    }
+  }
+
+  lazy val versionPropertiesImpl: Def.Initialize[Versions] = Def.setting {
+    /** Regexp that splits version number split into two parts: version and suffix.
+      * Examples of how the split is performed:
+      *
+      *  "2.11.5": ("2.11.5", null)
+      *  "2.11.5-acda7a": ("2.11.5", "-acda7a")
+      *  "2.11.5-SNAPSHOT": ("2.11.5", "-SNAPSHOT") */
+    val versionSplitted = """([\w+\.]+)(-[\w+\.]+)??""".r
+
+    val versionSplitted(ver, suffixOrNull) = version.value
+
+    val osgiSuffix = suffixOrNull match {
+      case null => "-VFINAL"
+      case "-SNAPSHOT" => ""
+      case suffixStr => suffixStr
+    }
+
+    def executeTool(tool: String) = {
+      val cmd =
+        if (System.getProperty("os.name").toLowerCase.contains("windows"))
+          s"cmd.exe /c tools\\$tool.bat -p"
+        else s"tools/$tool"
+      Process(cmd).lines.head
+    }
+
+    val commitDate = executeTool("get-scala-commit-date")
+    val commitSha = executeTool("get-scala-commit-sha")
+
+    Versions(
+      canonicalVersion = s"$ver-$commitDate-$commitSha",
+      mavenVersion = s"${version.value}",
+      osgiVersion = s"$ver.v$commitDate$osgiSuffix-$commitSha",
+      commitSha = commitSha,
+      commitDate = commitDate,
+      isRelease = !osgiSuffix.isEmpty
+    )
+  }
+
+  lazy val generateVersionPropertiesFileImpl: Def.Initialize[Task[File]] = Def.task {
+    val props = versionProperties.value.toProperties
+    val propFile = (resourceManaged in Compile).value / s"${thisProject.value.id}.properties"
+    props.put("copyright.string", copyrightString.value)
+
+    // unfortunately, this will write properties in arbitrary order
+    // this makes it harder to test for stability of generated artifacts
+    // consider using https://github.com/etiennestuder/java-ordered-properties
+    // instead of java.util.Properties
+    IO.write(props, null, propFile)
+    propFile
+  }
+
+  /** The global versions.properties data */
+  lazy val versionProps: Map[String, String] = {
+    val props = new Properties()
+    val in = new FileInputStream(file("versions.properties"))
+    try props.load(in)
+    finally in.close()
+    props.asScala.toMap
+  }
+
+  /** Get a subproject version number from `versionProps` */
+  def versionNumber(name: String): String =
+    versionProps(s"$name.version.number")
+}