1 files changed, 113 insertions, 0 deletions
diff --git a/examples/scala-js/tools/shared/src/main/scala/scala/scalajs/tools/corelib/CoreJSLibs.scala b/examples/scala-js/tools/shared/src/main/scala/scala/scalajs/tools/corelib/CoreJSLibs.scala
new file mode 100644
index 0000000..ecbea1f
--- /dev/null
+++ b/examples/scala-js/tools/shared/src/main/scala/scala/scalajs/tools/corelib/CoreJSLibs.scala
@@ -0,0 +1,113 @@
+/*                     __                                               *\
+**     ________ ___   / /  ___      __ ____  Scala.js tools             **
+**    / __/ __// _ | / /  / _ | __ / // __/  (c) 2013-2014, LAMP/EPFL   **
+**  __\ \/ /__/ __ |/ /__/ __ |/_// /_\ \    http://scala-js.org/       **
+** /____/\___/_/ |_/____/_/ | |__/ /____/                               **
+**                          |/____/                                     **
+\*                                                                      */
+
+
+package scala.scalajs.tools.corelib
+
+import java.net.URI
+
+import scala.scalajs.ir.ScalaJSVersions
+import scala.scalajs.tools.io._
+
+import scala.scalajs.tools.sem._
+
+import scala.collection.immutable.Seq
+import scala.collection.mutable
+
+object CoreJSLibs {
+
+  private val cachedLibBySemantics =
+    mutable.HashMap.empty[Semantics, VirtualJSFile]
+
+  private val ScalaJSEnvLines =
+    ScalaJSEnvHolder.scalajsenv.split("\n|\r\n?")
+
+  private val gitHubBaseURI =
+    new URI("https://raw.githubusercontent.com/scala-js/scala-js/")
+
+  def libs(semantics: Semantics): Seq[VirtualJSFile] = synchronized {
+    Seq(cachedLibBySemantics.getOrElseUpdate(semantics, makeLib(semantics)))
+  }
+
+  private def makeLib(semantics: Semantics): VirtualJSFile = {
+    new ScalaJSEnvVirtualJSFile(makeContent(semantics))
+  }
+
+  private def makeContent(semantics: Semantics): String = {
+    // This is a basic sort-of-C-style preprocessor
+
+    def getOption(name: String): String = name match {
+      case "asInstanceOfs" =>
+        semantics.asInstanceOfs.toString()
+      case "floats" =>
+        if (semantics.strictFloats) "Strict"
+        else "Loose"
+    }
+
+    var skipping = false
+    var skipDepth = 0
+    val lines = for (line <- ScalaJSEnvLines) yield {
+      val includeThisLine = if (skipping) {
+        if (line == "//!else" && skipDepth == 1) {
+          skipping = false
+          skipDepth = 0
+        } else if (line == "//!endif") {
+          skipDepth -= 1
+          if (skipDepth == 0)
+            skipping = false
+        } else if (line.startsWith("//!if ")) {
+          skipDepth += 1
+        }
+        false
+      } else {
+        if (line.startsWith("//!")) {
+          if (line.startsWith("//!if ")) {
+            val Array(_, option, op, value) = line.split(" ")
+            val optionValue = getOption(option)
+            val success = op match {
+              case "==" => optionValue == value
+              case "!=" => optionValue != value
+            }
+            if (!success) {
+              skipping = true
+              skipDepth = 1
+            }
+          } else if (line == "//!else") {
+            skipping = true
+            skipDepth = 1
+          } else if (line == "//!endif") {
+            // nothing to do
+          } else {
+            throw new MatchError(line)
+          }
+          false
+        } else {
+          true
+        }
+      }
+      if (includeThisLine) line
+      else "" // blank line preserves line numbers in source maps
+    }
+
+    lines.mkString("", "\n", "\n")
+  }
+
+  private class ScalaJSEnvVirtualJSFile(override val content: String) extends VirtualJSFile {
+    override def path: String = "scalajsenv.js"
+    override def version: Option[String] = Some("")
+    override def exists: Boolean = true
+
+    override def toURI: URI = {
+      if (!ScalaJSVersions.currentIsSnapshot)
+        gitHubBaseURI.resolve(s"v${ScalaJSVersions.current}/tools/$path")
+      else
+        super.toURI
+    }
+  }
+
+}