Reject failed inits

compiler/src/dotty/tools/repl/Rendering.scala

@@ -1,18 +1,20 @@
 package dotty.tools
 package repl
 
-import java.io.{ StringWriter, PrintWriter }
-import java.lang.{ ClassLoader, ExceptionInInitializerError }
+import java.io.{PrintWriter, StringWriter}
+import java.lang.{ClassLoader, ExceptionInInitializerError}
 import java.lang.reflect.InvocationTargetException
 
+import scala.util.Try
 import scala.runtime.ScalaRunTime
-
 import dotc.core.Contexts.Context
 import dotc.core.Denotations.Denotation
 import dotc.core.Flags
 import dotc.core.Symbols.Symbol
 import dotc.core.StdNames.str
 
+import scala.util.Try
+
 /** This rendering object uses `ClassLoader`s to accomplish crossing the 4th
  *  wall (i.e. fetching back values from the compiled class files put into a
  *  specific class loader capable of loading from memory) and rendering them.
@@ -72,21 +74,20 @@ private[repl] class Rendering(parentClassLoader: Option[ClassLoader] = None) {
     d.symbol.showUser
 
   /** Render value definition result */
-  def renderVal(d: Denotation)(implicit ctx: Context): Option[String] = {
+  def renderVal(d: Denotation)(implicit ctx: Context): Try[Option[String]] = {
     val dcl = d.symbol.showUser
 
-    try {
+    Try {
       val resultValue =
         if (d.symbol.is(Flags.Lazy)) Some("<lazy>")
         else valueOf(d.symbol)
 
       resultValue.map(value => s"$dcl = $value")
     }
-    catch { case ex: InvocationTargetException => Some(renderError(ex)) }
   }
 
   /** Render the stack trace of the underlying exception */
-  private def renderError(ex: InvocationTargetException): String = {
+  def renderError(ex: InvocationTargetException): String = {
     val cause = ex.getCause match {
       case ex: ExceptionInInitializerError => ex.getCause
       case ex => ex

compiler/src/dotty/tools/repl/ReplDriver.scala

@@ -1,6 +1,7 @@
 package dotty.tools.repl
 
 import java.io.PrintStream
+import java.lang.reflect.InvocationTargetException
 
 import dotty.tools.dotc.ast.Trees._
 import dotty.tools.dotc.ast.{tpd, untpd}
@@ -22,9 +23,11 @@ import dotty.tools.dotc.util.{SourceFile, SourcePosition}
 import dotty.tools.dotc.{CompilationUnit, Driver}
 import dotty.tools.io._
 import org.jline.reader._
+import java.lang.reflect.InvocationTargetException
 
 import scala.annotation.tailrec
 import scala.collection.JavaConverters._
+import scala.util.{Failure, Success}
 
 /** The state of the REPL contains necessary bindings instead of having to have
  *  mutation
@@ -224,13 +227,14 @@ class ReplDriver(settings: Array[String],
 
             val warnings = newState.context.reporter.removeBufferedMessages(newState.context)
             displayErrors(warnings)(newState) // display warnings
-            displayDefinitions(unit.tpdTree, newestWrapper)(newStateWithImports)
+
+            displayDefinitions(unit.tpdTree, newestWrapper)(newStateWithImports).getOrElse(state)
         }
       )
   }
 
   /** Display definitions from `tree` */
-  private def displayDefinitions(tree: tpd.Tree, newestWrapper: Name)(implicit state: State): State = {
+  private def displayDefinitions(tree: tpd.Tree, newestWrapper: Name)(implicit state: State): Option[State] = {
     implicit val ctx = state.context
 
     def resAndUnit(denot: Denotation) = {
@@ -263,15 +267,40 @@ class ReplDriver(settings: Array[String],
       val typeAliases =
         info.bounds.hi.typeMembers.filter(_.symbol.info.isTypeAlias)
 
-      (
-        typeAliases.map("// defined alias " + _.symbol.showUser) ++
-        defs.map(rendering.renderMethod) ++
-        vals.map(rendering.renderVal).flatten
-      ).foreach(str => out.println(SyntaxHighlighting.highlight(str)))
+      var renderedVals: List[Option[String]] = Nil
+      var error: InvocationTargetException = null
+      import scala.util.control.Breaks.{break, breakable}
+      breakable {
+        for (v <- vals) {
+          val render = rendering.renderVal(v)
+          render match {
+            case Success(rv) =>
+              renderedVals = renderedVals :+ rv
+            case Failure(th) => th match {
+              case ex: InvocationTargetException =>
+                error = ex
+                break()
+              case other =>
+                throw other
+            }
+          }
+        }
+      }
 
-      state.copy(valIndex = state.valIndex - vals.count(resAndUnit))
+      if (error != null) {
+        out.println(SyntaxHighlighting.highlight(rendering.renderError(error)))
+        rendering = new Rendering(classLoader)
+        None
+      } else {
+        (
+          typeAliases.map("// defined alias " + _.symbol.showUser) ++
+            defs.map(rendering.renderMethod) ++
+            renderedVals.flatten
+          ).foreach(str => out.println(SyntaxHighlighting.highlight(str)))
+        Some(state.copy(valIndex = state.valIndex - vals.count(resAndUnit)))
+      }
     }
-    else state
+    else Some(state)
 
     def isSyntheticCompanion(sym: Symbol) =
       sym.is(Module) && sym.is(Synthetic)
@@ -294,18 +323,13 @@ class ReplDriver(settings: Array[String],
 
 
     ctx.atPhase(ctx.typerPhase.next) { implicit ctx =>
-
       // Display members of wrapped module:
       tree.symbol.info.memberClasses
         .find(_.symbol.name == newestWrapper.moduleClassName)
-        .map { wrapperModule =>
+        .flatMap { wrapperModule =>
           displayTypeDefs(wrapperModule.symbol)
           displayMembers(wrapperModule.symbol)
         }
-        .getOrElse {
-          // user defined a trait/class/object, so no module needed
-          state
-        }
     }
   }