Fix reporter position

Author: nicolasstucki

compiler/src/dotty/tools/dotc/interpreter/Interpreter.scala

@@ -62,7 +62,7 @@ class Interpreter(implicit ctx: Context) {
    *
    *  If some error is encountered while interpreting a ctx.error is emitted and a StopInterpretation is thrown.
    */
-  private def interpretTreeImpl(tree: Tree, env: Env): Object = {
+  protected def interpretTreeImpl(tree: Tree, env: Env): Object = {
     // println(s"Interpreting:\n${tree.show}\n$env\n")
 
     implicit val pos: Position = tree.pos
@@ -72,12 +72,6 @@ class Interpreter(implicit ctx: Context) {
         if (quotedTree.isTerm) new scala.quoted.Exprs.TreeExpr(quotedTree)
         else new scala.quoted.Types.TreeType(quotedTree)
 
-      case tree: RefTree if tree.symbol eq defn.QuotedReporterDummy =>
-        new scala.quoted.Reporter {
-          override def error(message: String): Unit = ctx.error(message, pos)
-          override def warn(message: String): Unit = ctx.warning(message, pos)
-        }
-
       case Literal(Constant(c)) => c.asInstanceOf[Object]
 
       case Apply(fn, args) if fn.symbol.isConstructor =>

compiler/src/dotty/tools/dotc/transform/ReifyQuotes.scala

@@ -336,7 +336,7 @@ class ReifyQuotes extends MacroTransformWithImplicits {
             }
 
             val tree1 =
-              if (level == 0) cpy.Inlined(tree)(call, stagedBindings, Splicer.splice(seq(splicedBindings, body)))
+              if (level == 0) cpy.Inlined(tree)(call, stagedBindings, Splicer.splice(seq(splicedBindings, body).withPos(tree.pos)))
               else seq(stagedBindings, cpy.Select(expansion)(cpy.Inlined(tree)(call, splicedBindings, body), name))
             val tree2 = transform(tree1)
 

compiler/src/dotty/tools/dotc/transform/Splicer.scala

@@ -3,8 +3,11 @@ package transform
 
 import dotty.tools.dotc.ast.tpd
 import dotty.tools.dotc.core.Contexts._
+import dotty.tools.dotc.core.Decorators._
+import dotty.tools.dotc.core.Symbols._
 import dotty.tools.dotc.core.quoted._
 import dotty.tools.dotc.interpreter._
+import dotty.tools.dotc.util.SourcePosition
 
 /** Utility class to splice quoted expressions */
 object Splicer {
@@ -20,9 +23,18 @@ object Splicer {
   }
 
   /** Splice the Tree for a Quoted expression which is constructed via a reflective call to the given method */
-  private def reflectiveSplice(tree: Tree)(implicit ctx: Context): Tree = {
-    val interpreter = new Interpreter
-    interpreter.interpretTree[scala.quoted.Expr[_]](tree).map(PickledQuotes.quotedExprToTree).getOrElse(tree)
+  private def reflectiveSplice(tree0: Tree)(implicit ctx: Context): Tree = {
+    val interpreter = new Interpreter {
+      override protected def interpretTreeImpl(tree: Tree, env: Env): AnyRef = tree match {
+        case tree: RefTree if tree.symbol eq defn.QuotedReporterDummy => new Reporter(tree0.pos, ctx)
+        case _ => super.interpretTreeImpl(tree, env)
+      }
+    }
+    interpreter.interpretTree[scala.quoted.Expr[_]](tree0).map(PickledQuotes.quotedExprToTree).getOrElse(tree0)
   }
 
+  private class Reporter(pos: SourcePosition, ctx: Context) extends scala.quoted.Reporter {
+    override def error(message: String): Unit = ctx.error(message, pos)
+    override def warn(message: String): Unit = ctx.warning(message, pos)
+  }
 }

library/src/scala/quoted/Reporter.scala

@@ -1,14 +1,24 @@
 package scala.quoted
 
+/** Reporter for inlined quotes. By default Reporter.dummy is used,
+ *  but when in an inline splice the compilers reporter is used.
+ *
+ *  ```
+ *  inline def foo(): Unit = ~fooImpl() // The compiler reporter inserted here
+ *  def fooImpl()(implicit reporter: Reporter) = ???
+ *  ```
+ */
 trait Reporter {
   def error(message: String): Unit
   def warn(message: String): Unit
 }
 
 object Reporter {
+  /** Reporter that ignores all inputs */
   object DummyReporter extends Reporter {
     override def error(message: String): Unit = ()
     override def warn(message: String): Unit = ()
   }
+  /** Returns the default reporter that ignores all inputs */
   implicit def dummy: Reporter = DummyReporter
 }