src/Pure/System/isabelle_env.scala

+/*  Title:      Pure/System/isabelle_env.scala
+    Author:     Makarius
+
+Fundamental Isabelle system environment: quasi-static module with
+optional init operation.
+*/
+
+package isabelle
+
+
+import java.io.{File => JFile}
+
+import scala.jdk.CollectionConverters._
+
+
+
+object Isabelle_Env
+{
+  /** bootstrap information **/
+
+  def jdk_home(): String =
+  {
+    val java_home = System.getProperty("java.home", "")
+    val home = new JFile(java_home)
+    val parent = home.getParent
+    if (home.getName == "jre" && parent != null &&
+        (new JFile(new JFile(parent, "bin"), "javac")).exists) parent
+    else java_home
+  }
+
+  def bootstrap_directory(
+    preference: String, envar: String, property: String, description: String): String =
+  {
+    val value =
+      proper_string(preference) orElse  // explicit argument
+      proper_string(System.getenv(envar)) orElse  // e.g. inherited from running isabelle tool
+      proper_string(System.getProperty(property)) getOrElse  // e.g. via JVM application boot process
+      error("Unknown " + description + " directory")
+
+    if ((new JFile(value)).isDirectory) value
+    else error("Bad " + description + " directory " + quote(value))
+  }
+
+
+
+  /** raw process **/
+
+  /* raw process */
+
+  def process(command_line: List[String],
+    cwd: JFile = null,
+    env: Map[String, String] = settings(),
+    redirect: Boolean = false): Process =
+  {
+    val proc = new ProcessBuilder
+
+    // fragile on Windows:
+    // see https://docs.microsoft.com/en-us/cpp/cpp/main-function-command-line-args?view=msvc-160
+    proc.command(command_line.asJava)
+
+    if (cwd != null) proc.directory(cwd)
+    if (env != null) {
+      proc.environment.clear()
+      for ((x, y) <- env) proc.environment.put(x, y)
+    }
+    proc.redirectErrorStream(redirect)
+    proc.start
+  }
+
+  def process_output(proc: Process): (String, Int) =
+  {
+    proc.getOutputStream.close()
+
+    val output = File.read_stream(proc.getInputStream)
+    val rc =
+      try { proc.waitFor }
+      finally {
+        proc.getInputStream.close()
+        proc.getErrorStream.close()
+        proc.destroy()
+        Exn.Interrupt.dispose()
+      }
+    (output, rc)
+  }
+
+
+
+  /** implicit settings environment **/
+
+  abstract class Service
+
+  @volatile private var _settings: Option[Map[String, String]] = None
+  @volatile private var _services: Option[List[Class[Service]]] = None
+
+  def settings(): Map[String, String] =
+  {
+    if (_settings.isEmpty) init()  // unsynchronized check
+    _settings.get
+  }
+
+  def services(): List[Class[Service]] =
+  {
+    if (_services.isEmpty) init()  // unsynchronized check
+    _services.get
+  }
+
+  def getenv_error(name: String): Nothing =
+    error("Undefined Isabelle environment variable: " + quote(name))
+
+  def init(isabelle_root: String = "", cygwin_root: String = ""): Unit = synchronized
+  {
+    if (_settings.isEmpty || _services.isEmpty) {
+      val isabelle_root1 =
+        bootstrap_directory(isabelle_root, "ISABELLE_ROOT", "isabelle.root", "Isabelle root")
+
+      val cygwin_root1 =
+        if (Platform.is_windows)
+          bootstrap_directory(cygwin_root, "CYGWIN_ROOT", "cygwin.root", "Cygwin root")
+        else ""
+
+      if (Platform.is_windows) Cygwin.init(isabelle_root1, cygwin_root1)
+
+      def set_cygwin_root(): Unit =
+      {
+        if (Platform.is_windows)
+          _settings = Some(_settings.getOrElse(Map.empty) + ("CYGWIN_ROOT" -> cygwin_root1))
+      }
+
+      set_cygwin_root()
+
+      def default(env: Map[String, String], entry: (String, String)): Map[String, String] =
+        if (env.isDefinedAt(entry._1) || entry._2 == "") env
+        else env + entry
+
+      val env =
+      {
+        val temp_windows =
+        {
+          val temp = if (Platform.is_windows) System.getenv("TEMP") else null
+          if (temp != null && temp.contains('\\')) temp else ""
+        }
+        val user_home = System.getProperty("user.home", "")
+        val isabelle_app = System.getProperty("isabelle.app", "")
+
+        default(
+          default(
+            default(sys.env + ("ISABELLE_JDK_HOME" -> File.standard_path(jdk_home())),
+              "TEMP_WINDOWS" -> temp_windows),
+            "HOME" -> user_home),
+          "ISABELLE_APP" -> isabelle_app)
+      }
+
+      val settings =
+      {
+        val dump = JFile.createTempFile("settings", null)
+        dump.deleteOnExit
+        try {
+          val cmd1 =
+            if (Platform.is_windows)
+              List(cygwin_root1 + "\\bin\\bash", "-l",
+                File.standard_path(isabelle_root1 + "\\bin\\isabelle"))
+            else
+              List(isabelle_root1 + "/bin/isabelle")
+          val cmd = cmd1 ::: List("getenv", "-d", dump.toString)
+
+          val (output, rc) = process_output(process(cmd, env = env, redirect = true))
+          if (rc != 0) error(output)
+
+          val entries =
+            space_explode('\u0000', File.read(dump)).flatMap(
+              {
+                case Properties.Eq(a, b) => Some(a -> b)
+                case s => if (s.isEmpty || s.startsWith("=")) None else Some(s -> "")
+              }).toMap
+          entries + ("PATH" -> entries("PATH_JVM")) - "PATH_JVM"
+        }
+        finally { dump.delete }
+      }
+      _settings = Some(settings)
+      set_cygwin_root()
+
+      val variable = "ISABELLE_SCALA_SERVICES"
+      val services =
+        for (name <- space_explode(':', settings.getOrElse(variable, getenv_error(variable))))
+        yield {
+          def err(msg: String): Nothing =
+            error("Bad entry " + quote(name) + " in " + variable + "\n" + msg)
+          try { Class.forName(name).asInstanceOf[Class[Service]] }
+          catch {
+            case _: ClassNotFoundException => err("Class not found")
+            case exn: Throwable => err(Exn.message(exn))
+          }
+        }
+      _services = Some(services)
+    }
+  }
+}