From 557d2ea5560c2d0e9cae7f9a792329dfc5cb9573 Mon Sep 17 00:00:00 2001
Date: Fri, 29 Nov 2019 18:03:11 +0000
Subject: [PATCH] 8214345: infinite recursion while checking super class

Summary: <javac>: infinite recursion while checking super class
LLT: ClassBoundCheckingOverflow.java ClassBoundCheckingOverflow.out
Bug url: https://bugs.openjdk.java.net/browse/JDK-8214345
---
 .../share/classes/com/sun/tools/javac/comp/Check.java        |  5 ++++-
 .../tools/javac/generics/ClassBoundCheckingOverflow.java     | 12 ++++++++++++
 .../tools/javac/generics/ClassBoundCheckingOverflow.out      |  3 +++
 3 files changed, 19 insertions(+), 1 deletion(-)
 create mode 100644 test/langtools/tools/javac/generics/ClassBoundCheckingOverflow.java
 create mode 100644 test/langtools/tools/javac/generics/ClassBoundCheckingOverflow.out

diff --git a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Check.java b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Check.java
index 90cb9d189..b1f4abcb6 100644
--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Check.java
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Check.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -2716,6 +2716,8 @@ public class Check {
             if (type.isErroneous()) return;
             for (List<Type> l = types.interfaces(type); l.nonEmpty(); l = l.tail) {
                 Type it = l.head;
+                if (type.hasTag(CLASS) && !it.hasTag(CLASS)) continue; // JLS 8.1.5
+
                 Type oldit = seensofar.put(it.tsym, it);
                 if (oldit != null) {
                     List<Type> oldparams = oldit.allparams();
@@ -2729,6 +2731,7 @@ public class Check {
                 checkClassBounds(pos, seensofar, it);
             }
             Type st = types.supertype(type);
+            if (type.hasTag(CLASS) && !st.hasTag(CLASS)) return; // JLS 8.1.4
             if (st != Type.noType) checkClassBounds(pos, seensofar, st);
         }
 
diff --git a/test/langtools/tools/javac/generics/ClassBoundCheckingOverflow.java b/test/langtools/tools/javac/generics/ClassBoundCheckingOverflow.java
new file mode 100644
index 000000000..1aeb7d71a
--- /dev/null
+++ b/test/langtools/tools/javac/generics/ClassBoundCheckingOverflow.java
@@ -0,0 +1,12 @@
+/*
+ * @test /nodynamiccopyright/
+ * @bug 8214345
+ * @summary infinite recursion while checking super class
+ *
+ * @compile/fail/ref=ClassBoundCheckingOverflow.out -XDrawDiagnostics ClassBoundCheckingOverflow.java
+ */
+
+public class ClassBoundCheckingOverflow {
+    abstract class InfiniteLoop1<E extends InfiniteLoop1<E>> extends E {}
+    abstract class InfiniteLoop2<E extends InfiniteLoop2<E>> implements E {}
+}
diff --git a/test/langtools/tools/javac/generics/ClassBoundCheckingOverflow.out b/test/langtools/tools/javac/generics/ClassBoundCheckingOverflow.out
new file mode 100644
index 000000000..bed6acfd7
--- /dev/null
+++ b/test/langtools/tools/javac/generics/ClassBoundCheckingOverflow.out
@@ -0,0 +1,3 @@
+ClassBoundCheckingOverflow.java:10:70: compiler.err.type.found.req: (compiler.misc.type.parameter: E), (compiler.misc.type.req.class)
+ClassBoundCheckingOverflow.java:11:73: compiler.err.type.found.req: (compiler.misc.type.parameter: E), (compiler.misc.type.req.class)
+2 errors
-- 
2.12.3