Refactored browsing loaders so that they can be...

Refactored browsing loaders so that they can be more easily reused from
the builder. Review by plocinik.

1 files changed, 111 insertions, 0 deletions

diff --git a/src/compiler/scala/tools/nsc/symtab/BrowsingLoaders.scala b/src/compiler/scala/tools/nsc/symtab/BrowsingLoaders.scala
new file mode 100644
index 0000000000..1f2553d11e
--- /dev/null
+++ b/src/compiler/scala/tools/nsc/symtab/BrowsingLoaders.scala
@@ -0,0 +1,111 @@
+/* NSC -- new Scala compiler
+ * Copyright 2005-2010 LAMP/EPFL
+ * @author  Martin Odersky
+ */
+
+package scala.tools.nsc
+package symtab
+
+import scala.tools.nsc.io.AbstractFile
+import scala.tools.nsc.util.BatchSourceFile
+
+/** A subclass of SymbolLoaders that implements browsing behavior.
+ *  This class should be used whenever file dependencies and recompile sets
+ *  are managed automoatically.
+ */
+abstract class BrowsingLoaders extends SymbolLoaders {
+  import global._
+
+  import syntaxAnalyzer.{OutlineParser, MalformedInput}
+
+  /** In browse mode, it can happen that an encountered symbol is already
+   *  present. For instance, if the source file has a name different from
+   *  the classes and objects it contains, the symbol loader will always
+   *  reparse the source file. The symbols it encounters might already be loaded
+   *  as class files. In this case we return the one which has a sourcefile
+   *  (and the other has not), and issue an error if both have sourcefiles.
+   */
+  override protected def enterIfNew(owner: Symbol, member: Symbol, completer: SymbolLoader): Symbol = {
+    completer.sourcefile match {
+      case Some(src) =>
+        (if (member.isModule) member.moduleClass else member).sourceFile = src
+      case _ =>
+    }
+    val decls = owner.info.decls
+    val existing = decls.lookup(member.name)
+    if (existing == NoSymbol) {
+      decls enter member
+      member
+    } else if (existing.sourceFile == null) {
+      decls unlink existing
+      decls enter member
+      member
+    } else {
+      if (member.sourceFile != null) {
+        if (existing.sourceFile != member.sourceFile)
+          error(member+"is defined twice,"+
+                "\n in "+existing.sourceFile+
+                "\n and also in "+member.sourceFile)
+      }
+      existing
+    }
+  }
+
+  /** Browse the top-level of given abstract file `src` and enter
+   *  eny encountered top-level classes and modules in `root`
+   */
+  def browseTopLevel(root: Symbol, src: AbstractFile) {
+
+    class BrowserTraverser extends Traverser {
+      var packagePrefix = ""
+      var entered = 0
+      def addPackagePrefix(pkg: Tree): Unit = pkg match {
+        case Select(pre, name) =>
+          addPackagePrefix(pre)
+          packagePrefix += ("." + name)
+        case Ident(name) =>
+          if (packagePrefix.length != 0) packagePrefix += "."
+          packagePrefix += name
+        case _ =>
+          throw new MalformedInput(pkg.pos.point, "illegal tree node in package prefix: "+pkg)
+      }
+      override def traverse(tree: Tree): Unit = tree match {
+        case PackageDef(pkg, body) =>
+          addPackagePrefix(pkg)
+          body foreach traverse
+        case ClassDef(_, name, _, _) =>
+          if (packagePrefix == root.fullName) {
+            enterClass(root, name.toString, new SourcefileLoader(src))
+            entered += 1
+          } else println("prefixes differ: "+packagePrefix+","+root.fullName)
+        case ModuleDef(_, name, _) =>
+          if (packagePrefix == root.fullName) {
+            enterModule(root, name.toString, new SourcefileLoader(src))
+            entered += 1
+          } else println("prefixes differ: "+packagePrefix+","+root.fullName)
+        case _ =>
+      }
+    }
+
+    System.out.println("Browsing "+src)
+    val source = new BatchSourceFile(src)
+    val body = new OutlineParser(source).parse()
+    System.out.println(body)
+    val browser = new BrowserTraverser
+    browser.traverse(body)
+    if (browser.entered == 0)
+      warning("No classes or objects found in "+source+" that go in "+root)
+  }
+
+  /** Enter top-level symbols from a source file
+   */
+  override def enterToplevelsFromSource(root: Symbol, name: String, src: AbstractFile) {
+    try {
+      browseTopLevel(root, src)
+    } catch {
+      case ex: syntaxAnalyzer.MalformedInput =>
+        println("caught malformed input exception at offset "+ex.offset+": "+ex.msg)
+        super.enterToplevelsFromSource(root, name, src)
+    }
+  }
+}