Handle non fatal exceptions in splicer as compilation errors

Author: nicolasstucki

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

@@ -7,6 +7,8 @@ import dotty.tools.dotc.core.Decorators._
 import dotty.tools.dotc.core.quoted._
 import dotty.tools.dotc.interpreter._
 
+import scala.util.control.NonFatal
+
 import java.lang.reflect.InvocationTargetException
 
 /** Utility class to splice quoted expressions */
@@ -25,17 +27,21 @@ 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
-    try {
-      interpreter.interpretTree[scala.quoted.Expr[_]](tree).map(PickledQuotes.quotedExprToTree).getOrElse(tree)
-    } catch {
-      case ex: InvocationTargetException => tryRecoverFromTargetException(tree, ex)
-    }
+    val interpreted =
+      try interpreter.interpretTree[scala.quoted.Expr[_]](tree)
+      catch { case ex: InvocationTargetException => handleTargetException(tree, ex); None }
+    interpreted.fold(tree)(PickledQuotes.quotedExprToTree)
   }
 
-  private def tryRecoverFromTargetException(tree: Tree, ex: InvocationTargetException)(implicit ctx: Context): Tree = ex.getCause match {
-    case ex: scala.quoted.QuoteError =>
-      ctx.error(ex.getMessage, tree.pos)
-      EmptyTree
+  private def handleTargetException(tree: Tree, ex: InvocationTargetException)(implicit ctx: Context): Unit = ex.getCause match {
+    case ex: scala.quoted.QuoteError => ctx.error(ex.getMessage, tree.pos)
+    case NonFatal(ex) =>
+      val msg =
+        s"""Failed to evaluate inlined quote.
+           |  Caused by: ${ex.getMessage}
+           |  ${ex.getStackTrace.takeWhile(_.getClassName != "sun.reflect.NativeMethodAccessorImpl").mkString("\n  ")}
+         """.stripMargin
+      ctx.error(msg, tree.pos)
     case _ => throw ex
   }
 

tests/neg/quote-exception/Macro_1.scala

@@ -0,0 +1,8 @@
+import quoted._
+
+object Macro_1 {
+  inline def foo(inline b: Boolean): Unit = ~fooImpl(b)
+  def fooImpl(b: Boolean): Expr[Unit] =
+    if (b) '(println("foo(true)"))
+  else ???
+}

tests/neg/quote-exception/Test_2.scala

@@ -0,0 +1,6 @@
+import Macro_1._
+
+object Test_2 {
+  foo(true)
+  foo(false) // error: Failed to evaluate inlined quote. Caused by: an implementation is missing
+}