More debug options for printing

 - Mark splices in code under -print-debug
 - Print owners of all definitions under -print-debug-owners

Author: odersky

compiler/src/dotty/tools/dotc/config/ScalaSettings.scala

@@ -87,7 +87,6 @@ class ScalaSettings extends Settings.SettingGroup {
   val YdebugFlags = BooleanSetting("-Ydebug-flags", "Print all flags of definitions")
   val YdebugMissingRefs = BooleanSetting("-Ydebug-missing-refs", "Print a stacktrace when a required symbol is missing")
   val YdebugNames = BooleanSetting("-Ydebug-names", "Show internal representation of names")
-  val YdebugOwners = BooleanSetting("-Ydebug-owners", "Print all owners of definitions (requires -Yprint-syms)")
   val YtermConflict = ChoiceSetting("-Yresolve-term-conflict", "strategy", "Resolve term conflicts", List("package", "object", "error"), "error")
   val Ylog = PhasesSetting("-Ylog", "Log operations during")
   val YemitTasty = BooleanSetting("-Yemit-tasty", "Generate tasty in separate *.tasty file.")
@@ -113,6 +112,7 @@ class ScalaSettings extends Settings.SettingGroup {
   val YplainPrinter = BooleanSetting("-Yplain-printer", "Pretty-print using a plain printer.")
   val YprintSyms = BooleanSetting("-Yprint-syms", "when printing trees print info in symbols instead of corresponding info in trees.")
   val YprintDebug = BooleanSetting("-Yprint-debug", "when printing trees, print some extra information useful for debugging.")
+  val YprintDebugOwners = BooleanSetting("-Yprint-debug-owners", "when printing trees, print owners of definitions.")
   val YshowPrintErrors = BooleanSetting("-Yshow-print-errors", "don't suppress exceptions thrown during tree printing.")
   val YtestPickler = BooleanSetting("-Ytest-pickler", "self-test for pickling functionality; should be used with -Ystop-after:pickler")
   val YcheckReentrant = BooleanSetting("-Ycheck-reentrant", "check that compiled program does not contain vars that can be accessed from a global root.")

compiler/src/dotty/tools/dotc/printing/RefinedPrinter.scala

@@ -446,9 +446,11 @@ class RefinedPrinter(_ctx: Context) extends PlainPrinter(_ctx) {
       case EmptyTree =>
         "<empty>"
       case TypedSplice(t) =>
-        toText(t)
+        if (ctx.settings.YprintDebug.value) "[" ~ toText(t) ~ "]#TS#"
+        else toText(t)
       case tpd.UntypedSplice(t) =>
-        toText(t)
+        if (ctx.settings.YprintDebug.value) "[" ~ toText(t) ~ ":" ~ toText(tree.typeOpt) ~ "]#US#"
+        else toText(t)
       case tree @ ModuleDef(name, impl) =>
         withEnclosingDef(tree) {
           modText(tree.mods, NoSymbol, keywordStr("object")) ~~ nameIdText(tree) ~ toTextTemplate(impl)
@@ -605,11 +607,14 @@ class RefinedPrinter(_ctx: Context) extends PlainPrinter(_ctx) {
     else toText(tree.name) ~ idText(tree)
   }
 
+  private def toTextOwner(tree: Tree[_]) =
+    "[owner = " ~ tree.symbol.owner.show ~ "]" provided ctx.settings.YprintDebugOwners.value
+
   protected def dclTextOr[T >: Untyped](tree: Tree[T])(treeText: => Text) =
-    if (useSymbol(tree))
-      annotsText(tree.symbol) ~~ dclText(tree.symbol) ~
-        ( " <in " ~ toText(tree.symbol.owner) ~ ">" provided ctx.settings.YdebugOwners.value)
-    else treeText
+    toTextOwner(tree) ~ {
+      if (useSymbol(tree)) annotsText(tree.symbol) ~~ dclText(tree.symbol)
+      else treeText
+    }
 
   def tparamsText[T >: Untyped](params: List[Tree[T]]): Text =
     "[" ~ toText(params, ", ") ~ "]" provided params.nonEmpty