WIP Extract quote reification from Staging

Author: nicolasstucki

compiler/src/dotty/tools/dotc/Compiler.scala

@@ -45,8 +45,9 @@ class Compiler {
 
   /** Phases dealing with TASTY tree pickling and unpickling */
   protected def picklerPhases: List[List[Phase]] =
+    List(new Staging) ::            // Check levels and expand macros
     List(new Pickler) ::            // Generate TASTY info
-    List(new Staging) ::            // Expand macros and turn quoted trees into explicit run-time data structures
+    List(new ReifyQuotes) ::        // Turn quoted trees into explicit run-time data structures
     Nil
 
   /** Phases dealing with the transformation from pickled trees to backend trees */

compiler/src/dotty/tools/dotc/ast/TreeTypeMap.scala

@@ -162,7 +162,7 @@ class TreeTypeMap(
       assert(!to.exists(substFrom contains _))
       assert(!from.exists(newOwners contains _))
       assert(!to.exists(oldOwners contains _))
-      new TreeTypeMap(
+      newTreeTypeMap(
         typeMap,
         treeMap,
         from ++ oldOwners,
@@ -171,6 +171,11 @@ class TreeTypeMap(
         to ++ substTo)
     }
 
+  protected def newTreeTypeMap(typeMap: Type => Type, treeMap: tpd.Tree => tpd.Tree,
+                               oldOwners: List[Symbol], newOwners: List[Symbol], substFrom: List[Symbol], substTo: List[Symbol]) = {
+    new TreeTypeMap(typeMap, treeMap, oldOwners, newOwners, substFrom, substTo)
+  }
+
   /** Apply `typeMap` and `ownerMap` to given symbols `syms`
    *  and return a treemap that contains the substitution
    *  between original and mapped symbols.

compiler/src/dotty/tools/dotc/ast/tpd.scala

@@ -1113,6 +1113,9 @@ object tpd extends Trees.Instance[Type] with TypedTreeInfo {
   /** A key to be used in a context property that tracks enclosing inlined calls */
   private val InlinedCalls = new Property.Key[List[Tree]]
 
+  /** A key to be used in a context property that tracks the quoteation level */
+  private val QuotationLevel = new Property.Key[Int]
+
   /** Record an enclosing inlined call.
    *  EmptyTree calls (for parameters) cancel the next-enclosing call in the list instead of being added to it.
    *  We assume parameters are never nested inside parameters.
@@ -1134,6 +1137,18 @@ object tpd extends Trees.Instance[Type] with TypedTreeInfo {
   def enclosingInlineds(implicit ctx: Context): List[Tree] =
     ctx.property(InlinedCalls).getOrElse(Nil)
 
+  /** All enclosing calls that are currently inlined, from innermost to outermost. */
+  def quotationLevel(implicit ctx: Context): Int =
+    ctx.property(QuotationLevel).getOrElse(0)
+
+  /** Context with an incremented quotation level. */
+  def quoteContext(implicit ctx: Context): Context =
+    ctx.fresh.setProperty(QuotationLevel, quotationLevel + 1)
+
+  /** Context with a decremented quotation level. */
+  def spliceContext(implicit ctx: Context): Context =
+    ctx.fresh.setProperty(QuotationLevel, quotationLevel - 1)
+
   /** The source file where the symbol of the `inline` method referred to by `call`
    *  is defined
    */

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

@@ -249,8 +249,12 @@ class RefinedPrinter(_ctx: Context) extends PlainPrinter(_ctx) {
   protected def blockText[T >: Untyped](trees: List[Tree[T]]): Text =
     ("{" ~ toText(trees, "\n") ~ "}").close
 
-  protected def typeApplyText[T >: Untyped](tree: TypeApply[T]): Text =
-    toTextLocal(tree.fun) ~ "[" ~ toTextGlobal(tree.args, ", ") ~ "]"
+  protected def typeApplyText[T >: Untyped](tree: TypeApply[T]): Text = {
+    if (tree.fun.hasType && tree.fun.symbol == defn.QuotedType_apply)
+      keywordStr("'[") ~ toTextGlobal(tree.args, ", ") ~ keywordStr("]")
+    else
+      toTextLocal(tree.fun) ~ "[" ~ toTextGlobal(tree.args, ", ") ~ "]"
+  }
 
   protected def toTextCore[T >: Untyped](tree: Tree[T]): Text = {
     import untpd.{modsDeco => _, _}
@@ -318,7 +322,8 @@ class RefinedPrinter(_ctx: Context) extends PlainPrinter(_ctx) {
         if (name.isTypeName) typeText(txt)
         else txt
       case tree @ Select(qual, name) =>
-        if (tree.hasType && tree.symbol == defn.QuotedExpr_~ || tree.symbol == defn.QuotedType_~) keywordStr("~(") ~ toTextLocal(qual) ~ keywordStr(")")
+        if (tree.hasType && tree.symbol == defn.QuotedExpr_~) keywordStr("~(") ~ toTextLocal(qual) ~ keywordStr(")")
+        else if (tree.hasType && tree.symbol == defn.QuotedType_~) typeText("~(") ~ toTextLocal(qual) ~ typeText(")")
         else if (qual.isType) toTextLocal(qual) ~ "#" ~ typeText(toText(name))
         else toTextLocal(qual) ~ ("." ~ nameIdText(tree) provided name != nme.CONSTRUCTOR)
       case tree: This =>
@@ -332,8 +337,6 @@ class RefinedPrinter(_ctx: Context) extends PlainPrinter(_ctx) {
           }
         else if (fun.hasType && fun.symbol == defn.QuotedExpr_apply)
           keywordStr("'{") ~ toTextGlobal(args, ", ") ~ keywordStr("}")
-        else if (fun.hasType && fun.symbol == defn.QuotedType_apply)
-          keywordStr("'[") ~ toTextGlobal(args, ", ") ~ keywordStr("]")
         else
           toTextLocal(fun) ~ "(" ~ toTextGlobal(args, ", ") ~ ")"
       case tree: TypeApply =>

compiler/src/dotty/tools/dotc/tastyreflect/TreeOpsImpl.scala

@@ -776,7 +776,7 @@ trait TreeOpsImpl extends scala.tasty.reflect.TreeOps with CoreImpl with Helpers
         tpd.Return(expr, ctx.owner)
 
       def copy(original: Tree)(expr: Term)(implicit ctx: Context): Return =
-        tpd.cpy.Return(original)(expr, tpd.EmptyTree)
+        tpd.cpy.Return(original)(expr, tpd.ref(ctx.owner))
 
       def unapply(x: Term)(implicit ctx: Context): Option[Term] = x match {
         case x: tpd.Return => Some(x.expr)