From ccf6c2ab3822729ff23eb917ee625f9e79804d53 Mon Sep 17 00:00:00 2001
From: Nicolas Stucki <nicolas.stucki@gmail.com>
Date: Thu, 17 Sep 2020 10:21:13 +0200
Subject: [PATCH] Fix #9801: Make sure the errors are reported

---
 .../dotty/tools/dotc/transform/Splicer.scala  |  4 ++--
 tests/neg-macros/i9801/Macro_1.scala          | 20 +++++++++++++++++++
 tests/neg-macros/i9801/Test_2.scala           |  1 +
 tests/neg-macros/i9801b/Macro_1.scala         | 14 +++++++++++++
 tests/neg-macros/i9801b/Test_2.scala          |  1 +
 5 files changed, 38 insertions(+), 2 deletions(-)
 create mode 100644 tests/neg-macros/i9801/Macro_1.scala
 create mode 100644 tests/neg-macros/i9801/Test_2.scala
 create mode 100644 tests/neg-macros/i9801b/Macro_1.scala
 create mode 100644 tests/neg-macros/i9801b/Test_2.scala

diff --git a/compiler/src/dotty/tools/dotc/transform/Splicer.scala b/compiler/src/dotty/tools/dotc/transform/Splicer.scala
index addc3edd6e07..8bece8e32b07 100644
--- a/compiler/src/dotty/tools/dotc/transform/Splicer.scala
+++ b/compiler/src/dotty/tools/dotc/transform/Splicer.scala
@@ -65,7 +65,7 @@ object Splicer {
           EmptyTree
         case ex: StopInterpretation =>
           report.error(ex.msg, ex.pos)
-          EmptyTree
+          ref(defn.Predef_undefined).withType(ErrorType(ex.msg))
         case NonFatal(ex) =>
           val msg =
             s"""Failed to evaluate macro.
@@ -73,7 +73,7 @@ object Splicer {
                |    ${ex.getStackTrace.takeWhile(_.getClassName != "dotty.tools.dotc.transform.Splicer$").drop(1).mkString("\n    ")}
              """.stripMargin
           report.error(msg, pos)
-          EmptyTree
+          ref(defn.Predef_undefined).withType(ErrorType(msg))
       }
   }
 
diff --git a/tests/neg-macros/i9801/Macro_1.scala b/tests/neg-macros/i9801/Macro_1.scala
new file mode 100644
index 000000000000..5bf2106548f9
--- /dev/null
+++ b/tests/neg-macros/i9801/Macro_1.scala
@@ -0,0 +1,20 @@
+import scala.quoted._
+
+def f() = ()
+
+def triggerStackOverflow(n: Int): Expr[Double] = {
+  val r = triggerStackOverflow(n - 1)
+  f()
+  r
+}
+
+inline def loop(inline prog: Double): Double = ${impl('prog)}
+
+def impl(prog: Expr[Double])(using QuoteContext) : Expr[Double] =
+  try {
+    triggerStackOverflow(0)
+  } catch {
+    case e =>
+      qctx.tasty.error(e.getMessage, prog.unseal.pos)
+      '{ 42.0 }
+  }
diff --git a/tests/neg-macros/i9801/Test_2.scala b/tests/neg-macros/i9801/Test_2.scala
new file mode 100644
index 000000000000..7a79536738c3
--- /dev/null
+++ b/tests/neg-macros/i9801/Test_2.scala
@@ -0,0 +1 @@
+def test: Unit = loop(4) // error
diff --git a/tests/neg-macros/i9801b/Macro_1.scala b/tests/neg-macros/i9801b/Macro_1.scala
new file mode 100644
index 000000000000..87360ff06093
--- /dev/null
+++ b/tests/neg-macros/i9801b/Macro_1.scala
@@ -0,0 +1,14 @@
+import scala.quoted._
+
+def f() = ()
+
+def triggerStackOverflow(n: Int): Expr[Double] = {
+  val r = triggerStackOverflow(n - 1)
+  f()
+  r
+}
+
+inline def loop(inline prog: Double): Double = ${impl('prog)}
+
+def impl(prog: Expr[Double])(using QuoteContext) : Expr[Double] =
+  triggerStackOverflow(0)
diff --git a/tests/neg-macros/i9801b/Test_2.scala b/tests/neg-macros/i9801b/Test_2.scala
new file mode 100644
index 000000000000..7a79536738c3
--- /dev/null
+++ b/tests/neg-macros/i9801b/Test_2.scala
@@ -0,0 +1 @@
+def test: Unit = loop(4) // error