8158224: NullPointerException in com.sun.tools.javac.comp.Modules.checkCyclicDependencies when module missing

Reviewed-by: jlahoda

langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Modules.java

@@ -757,7 +757,9 @@ public class Modules extends JCTree.Visitor {
 
         @Override
         public void visitRequires(JCRequires tree) {
-            msym.directives = msym.directives.prepend(tree.directive);
+            if (tree.directive != null) {
+                msym.directives = msym.directives.prepend(tree.directive);
+            }
         }
 
         @Override
@@ -1214,9 +1216,9 @@ public class Modules extends JCTree.Visitor {
 
     private void checkCyclicDependencies(JCModuleDecl mod) {
         for (JCDirective d : mod.directives) {
-            if (!d.hasTag(Tag.REQUIRES))
+            JCRequires rd;
+            if (!d.hasTag(Tag.REQUIRES) || (rd = (JCRequires) d).directive == null)
                 continue;
-            JCRequires rd = (JCRequires) d;
             Set<ModuleSymbol> nonSyntheticDeps = new HashSet<>();
             List<ModuleSymbol> queue = List.of(rd.directive.module);
             while (queue.nonEmpty()) {

langtools/test/tools/javac/modules/T8158224/Processor.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2016, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+import java.util.Set;
+import javax.annotation.processing.AbstractProcessor;
+import javax.annotation.processing.RoundEnvironment;
+import javax.annotation.processing.SupportedAnnotationTypes;
+import javax.annotation.processing.SupportedSourceVersion;
+import javax.lang.model.element.TypeElement;
+import javax.lang.model.SourceVersion;
+
+@SupportedAnnotationTypes("Blah")
+@SupportedSourceVersion(SourceVersion.RELEASE_6)
+public class Processor extends AbstractProcessor {
+
+    @Override
+    public boolean process(Set<? extends TypeElement> tE, RoundEnvironment env) {
+        return true;
+    }
+}

langtools/test/tools/javac/modules/T8158224/T8158224.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2016, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8158224
+ * @summary NullPointerException in com.sun.tools.javac.comp.Modules.checkCyclicDependencies when module missing
+ * @build Processor
+ * @compile/fail/ref=T8158224.out -XDrawDiagnostics -processor Processor mods/foo/module-info.java
+ */
+
+// No code here, this file is just to host test description.

langtools/test/tools/javac/modules/T8158224/T8158224.out

@@ -0,0 +1,2 @@
+module-info.java:4:14: compiler.err.module.not.found: nonexistent
+1 error

langtools/test/tools/javac/modules/T8158224/mods/foo/module-info.java

@@ -0,0 +1,5 @@
+/* /nodynamiccopyright/ */
+
+module foo {
+    requires nonexistent;
+}