Trying to get fsc doing the right thing with re...

Trying to get fsc doing the right thing with respect to absolute and
relative paths. My knowledge of the problem had heretofore been second
hand, and my understanding of it incomplete. The real problem I have
determined is that there are a bunch of different things which go wrong
if relative paths start being resolved from a different base, each of
which needs custom handling.

  classpath-style options, e.g. fsc -cp ../foo.jar
  path-style options, e.g. fsc -d ../mydir
  file arguments, e.g. fsc ../foo.scala

So it was more work than I had realized, or I probably wouldn't have
even touched it. But now it seems to be working as one would want. I
also poured some readability onto the fsc help output.

Closes #4395, no review, but community input would be great.

1 files changed, 29 insertions, 1 deletions

diff --git a/src/compiler/scala/tools/nsc/OfflineCompilerCommand.scala b/src/compiler/scala/tools/nsc/OfflineCompilerCommand.scala
index 786bcb1eb5..ef974da965 100644
--- a/src/compiler/scala/tools/nsc/OfflineCompilerCommand.scala
+++ b/src/compiler/scala/tools/nsc/OfflineCompilerCommand.scala
@@ -5,10 +5,38 @@
 
 package scala.tools.nsc
 
+import settings.FscSettings
+import io.Directory
+
 /** A compiler command for the offline compiler.
  *
  * @author Martin Odersky and Lex Spoon
  */
-class OfflineCompilerCommand(arguments: List[String], settings: Settings) extends CompilerCommand(arguments, settings) {
+class OfflineCompilerCommand(arguments: List[String], settings: FscSettings) extends CompilerCommand(arguments, settings) {
+  import settings.currentDir
+  def extraFscArgs = List(currentDir.name, currentDir.value)
+
+  locally {
+    // if -current-dir is unset, we're on the client and need to obtain it.
+    if (currentDir.isDefault) {
+      // Prefer env variable PWD to system property user.dir because the former
+      // deals better with paths not rooted at / (filesystem mounts.)
+      val baseDirectory = System.getenv("PWD") match {
+        case null   => Directory.Current getOrElse Directory("/")
+        case dir    => Directory(dir)
+      }
+      currentDir.value = baseDirectory.path
+    }
+    else {
+      // Otherwise we're on the server and will use it to absolutize the paths.
+      settings.absolutize(currentDir.value)
+    }
+  }
+
   override def cmdName = "fsc"
+  override def usageMsg = (
+    createUsageMsg("where possible fsc", false, x => x.isStandard && settings.isFscSpecific(x.name)) +
+    "\nStandard scalac options also available:\n  " +
+    createUsageMsg(x => x.isStandard && !settings.isFscSpecific(x.name))
+  )
 }