First version of position pickler.

5 files changed, 131 insertions, 0 deletions

diff --git a/src/dotty/tools/dotc/core/pickling/Edge.scala b/src/dotty/tools/dotc/core/pickling/Edge.scala
new file mode 100644
index 000000000..543f85831
--- /dev/null
+++ b/src/dotty/tools/dotc/core/pickling/Edge.scala
@@ -0,0 +1,22 @@
+package dotty.tools.dotc
+package core.pickling
+
+import util.Positions._
+import ast.tpd._
+import core.Contexts._
+
+abstract class Edge {
+  def offset(pos: Position): Int
+  def seq(op1: () => Unit, op2: () => Unit): Unit
+}
+
+object Edge {
+  object left extends Edge {
+    def offset(pos: Position): Int = pos.start
+    def seq(op1: () => Unit, op2: () => Unit) = { op1(); op2() }
+  }
+  object right extends Edge {
+    def offset(pos: Position): Int = pos.end
+    def seq(op1: () => Unit, op2: () => Unit) = { op2(); op1() }
+  }
+}
\ No newline at end of file
diff --git a/src/dotty/tools/dotc/core/pickling/PositionBuffer.scala b/src/dotty/tools/dotc/core/pickling/PositionBuffer.scala
new file mode 100644
index 000000000..f564e364d
--- /dev/null
+++ b/src/dotty/tools/dotc/core/pickling/PositionBuffer.scala
@@ -0,0 +1,33 @@
+package dotty.tools
+package dotc
+package core
+package pickling
+
+import TastyBuffer.Addr
+
+class PositionBuffer extends TastyBuffer(100000) { thisBuffer =>
+  
+  class PositionRecorder(val edge: Edge) extends TastyBuffer(thisBuffer.bytes.size / 2) {
+    private var lastOffset: Int = -1
+    private var lastIndex: Int = 0
+    def record(addr: Addr, offset: Int): Unit = 
+      if (offset != lastOffset) {
+        if (lastOffset < 0) lastOffset = 0
+        writeInt(offset - lastOffset)
+        writeInt(addr.index - lastIndex)
+        lastOffset = offset
+        lastIndex = addr.index
+      }
+  }
+  
+  val startPos = new PositionRecorder(Edge.left)
+  val endPos = new PositionRecorder(Edge.right)
+
+  /** Final assembly: copy startPos and endPos into own bytes */
+  override def assemble(): Unit = {
+    writeNat(startPos.length)
+    writeBytes(startPos.bytes, startPos.length)
+    writeNat(endPos.length)
+    writeBytes(endPos.bytes, endPos.length)
+  }
+}
\ No newline at end of file
diff --git a/src/dotty/tools/dotc/core/pickling/PositionPickler.scala b/src/dotty/tools/dotc/core/pickling/PositionPickler.scala
new file mode 100644
index 000000000..0cf519b23
--- /dev/null
+++ b/src/dotty/tools/dotc/core/pickling/PositionPickler.scala
@@ -0,0 +1,51 @@
+package dotty.tools
+package dotc
+package core
+package pickling
+
+import ast.tpd._
+import PickleFormat._
+import core._
+import Contexts._, Symbols._, Types._, Names._, Constants._, Decorators._, Annotations._
+import collection.mutable
+import TastyBuffer._
+
+class PositionPickler(pickler: TastyPickler, addrOfTree: Tree => Option[Addr]) {
+  val buf = new PositionBuffer
+  pickler.newSection("Positions", buf)
+  import buf._
+  
+  val noOp = () => ()
+  
+  def traverseAll(root: Tree, recorder: PositionRecorder)(implicit ctx: Context) = {
+    import recorder.edge.{seq, offset}
+    
+    def elemsTraversal(xs: TraversableOnce[Any]): () => Unit = 
+      (noOp /: xs) ((op, x) => () => seq(op, elemTraversal(x)))
+
+    def elemTraversal(x: Any): () => Unit = () => x match {        
+      case x: Tree @ unchecked =>
+        if (x.pos.exists)
+          for (addr <- addrOfTree(x))
+            recorder.record(addr, offset(x.pos))
+        
+        val annotTraversal = x match {
+          case x: MemberDef => elemsTraversal(x.symbol.annotations)
+          case _ => noOp
+        }
+        val childrenTraversal = elemsTraversal(x.productIterator)
+        seq(annotTraversal, childrenTraversal)
+      case xs: List[_] =>
+        elemsTraversal(xs)()
+      case _ =>
+        ()
+    }
+ 
+    elemTraversal(root)()
+  }
+  
+  def picklePositions(root: Tree)(implicit ctx: Context) = {
+    traverseAll(root, startPos)
+    traverseAll(root, endPos)
+  }
+}
\ No newline at end of file
diff --git a/src/dotty/tools/dotc/core/pickling/TastyPrinter.scala b/src/dotty/tools/dotc/core/pickling/TastyPrinter.scala
index 8056e600d..cf531ecac 100644
--- a/src/dotty/tools/dotc/core/pickling/TastyPrinter.scala
+++ b/src/dotty/tools/dotc/core/pickling/TastyPrinter.scala
@@ -34,6 +34,7 @@ class TastyPrinter(bytes: Array[Byte])(implicit ctx: Context) {
     printNames()
     println("Trees:")
     unpickle(new TreeUnpickler)
+    unpickle(new PositionUnpickler)
   }
   
   class TreeUnpickler extends SectionUnpickler[Unit]("ASTs") {
@@ -101,4 +102,26 @@ class TastyPrinter(bytes: Array[Byte])(implicit ctx: Context) {
       }
     }
   }
+  
+  class PositionUnpickler extends SectionUnpickler[Unit]("Positions") {
+    def unpickle(reader: TastyReader, tastyName: TastyName.Table): Unit = {
+      import reader._
+
+      def unpickleOffsets(edge: Edge): Unit = {
+        var lastOffset = 0
+        var lastAddr = 0
+        val length = readNat()
+        println(s"$length offset bytes")
+        val end = currentAddr + length
+        until(end) {
+          lastOffset += readInt()
+          lastAddr += readInt()
+          println(s"$lastOffset: $lastAddr")
+        }
+      }
+      
+      unpickleOffsets(Edge.left)
+      unpickleOffsets(Edge.right)
+    }
+  }
 }
\ No newline at end of file
diff --git a/src/dotty/tools/dotc/transform/Pickler.scala b/src/dotty/tools/dotc/transform/Pickler.scala
index f080aa7ad..aa133eeb4 100644
--- a/src/dotty/tools/dotc/transform/Pickler.scala
+++ b/src/dotty/tools/dotc/transform/Pickler.scala
@@ -20,6 +20,8 @@ class Pickler extends MiniPhaseTransform { thisTransform =>
       
       val treePkl = new TreePickler(pickler)
       treePkl.pickle(tree)
+      new PositionPickler(pickler, treePkl.buf.addrOfTree).picklePositions(tree)
+
       val bytes = pickler.assembleParts()
       def rawBytes = // not needed right now, but useful to print raw format.
         bytes.iterator.grouped(10).toList.zipWithIndex.map {