From 9aa2915b7bb251066bcc20209978b1d5851c15ca Mon Sep 17 00:00:00 2001
From: Nicolas Stucki <nicolas.stucki@gmail.com>
Date: Mon, 26 Mar 2018 14:29:56 +0200
Subject: [PATCH] Fix #4185: Do not check names for modules that will not be
 emitted

---
 compiler/src/dotty/tools/backend/jvm/GenBCode.scala   | 7 +++++--
 compiler/test/dotty/tools/dotc/CompilationTests.scala | 1 +
 tests/pos-special/i4185.scala                         | 4 ++++
 3 files changed, 10 insertions(+), 2 deletions(-)
 create mode 100644 tests/pos-special/i4185.scala

diff --git a/compiler/src/dotty/tools/backend/jvm/GenBCode.scala b/compiler/src/dotty/tools/backend/jvm/GenBCode.scala
index 65bd5ca27d7d..ca21867fd711 100644
--- a/compiler/src/dotty/tools/backend/jvm/GenBCode.scala
+++ b/compiler/src/dotty/tools/backend/jvm/GenBCode.scala
@@ -207,8 +207,11 @@ class GenBCodePipeline(val entryPoints: List[Symbol], val int: DottyBackendInter
           }
         }
         checkName(claszSymbol)
-        if (int.symHelper(claszSymbol).isModuleClass)
-          checkName(claszSymbol.companionModule)
+        if (int.symHelper(claszSymbol).isModuleClass) {
+          val companionModule = claszSymbol.companionModule
+          if (int.symHelper(companionModule.owner).isPackageClass)
+            checkName(companionModule)
+        }
 
         // -------------- mirror class, if needed --------------
         val mirrorC =
diff --git a/compiler/test/dotty/tools/dotc/CompilationTests.scala b/compiler/test/dotty/tools/dotc/CompilationTests.scala
index 694dd96012e7..be0eca287ac9 100644
--- a/compiler/test/dotty/tools/dotc/CompilationTests.scala
+++ b/compiler/test/dotty/tools/dotc/CompilationTests.scala
@@ -59,6 +59,7 @@ class CompilationTests extends ParallelTesting {
     compileFile("tests/pos-special/i3323b.scala", defaultOptions.and("-Xfatal-warnings")) +
     compileFile("tests/pos-special/i3589-b.scala", defaultOptions.and("-Xfatal-warnings")) +
     compileFile("tests/pos-special/i4166.scala", defaultOptions.and("-Xfatal-warnings")) +
+    compileFile("tests/pos-special/i4185.scala", defaultOptions.and("-Xfatal-warnings")) +
     compileFile("tests/pos-special/completeFromSource/Test.scala", defaultOptions.and("-sourcepath", "tests/pos-special")) +
     compileFile("tests/pos-special/completeFromSource/Test2.scala", defaultOptions.and("-sourcepath", "tests/pos-special")) +
     compileFile("tests/pos-special/completeFromSource/Test3.scala", defaultOptions.and("-sourcepath", "tests/pos-special", "-scansource")) +
diff --git a/tests/pos-special/i4185.scala b/tests/pos-special/i4185.scala
new file mode 100644
index 000000000000..10db2d672eea
--- /dev/null
+++ b/tests/pos-special/i4185.scala
@@ -0,0 +1,4 @@
+object ord {
+  class Ord
+  object Ord
+}