8196519: Incomplete classpath causes infinite recursion in Resolve.isAccessible

ErrorType.getEnclosingType returns noType rather than self.

Reviewed-by: mcimadamore, cushon

src/jdk.compiler/share/classes/com/sun/tools/javac/code/Type.java

@@ -2359,7 +2359,7 @@ public abstract class Type extends AnnoConstruct implements TypeMirror {
 
         public Type constType(Object constValue) { return this; }
         @DefinedBy(Api.LANGUAGE_MODEL)
-        public Type getEnclosingType()           { return this; }
+        public Type getEnclosingType()           { return Type.noType; }
         public Type getReturnType()              { return this; }
         public Type asSub(Symbol sym)            { return this; }
 

test/langtools/tools/javac/processing/model/MissingClassRecursiveAccessible.java

@@ -0,0 +1,166 @@
+/*
+ * Copyright (c) 2018, 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 8196519
+ * @summary Verify that enclosing type of an ErrorType is not the ErrorType itself.
+ * @library /tools/lib
+ * @modules jdk.compiler/com.sun.tools.javac.api
+ *          jdk.compiler/com.sun.tools.javac.main
+ * @build toolbox.TestRunner toolbox.ToolBox MissingClassRecursiveAccessible
+ * @run main MissingClassRecursiveAccessible
+ */
+
+import java.io.PrintWriter;
+import java.io.StringWriter;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.Arrays;
+
+import javax.lang.model.element.TypeElement;
+import javax.lang.model.type.ErrorType;
+import javax.lang.model.type.TypeKind;
+import javax.lang.model.type.TypeMirror;
+import javax.tools.JavaCompiler;
+import javax.tools.JavaCompiler.CompilationTask;
+import javax.tools.StandardJavaFileManager;
+import javax.tools.ToolProvider;
+
+import com.sun.source.tree.CompilationUnitTree;
+import com.sun.source.tree.MemberSelectTree;
+import com.sun.source.util.TreePath;
+import com.sun.source.util.TreePathScanner;
+import com.sun.source.util.Trees;
+import com.sun.tools.javac.*;
+import toolbox.JavacTask;
+import toolbox.TestRunner;
+import toolbox.TestRunner.Test;
+import toolbox.ToolBox;
+
+public class MissingClassRecursiveAccessible extends TestRunner {
+
+    public static void main(String... args) throws Exception {
+        new MissingClassRecursiveAccessible().runTests(m -> new Object[] { Paths.get(m.getName()) });
+    }
+
+    private final ToolBox tb = new ToolBox();
+
+    public MissingClassRecursiveAccessible() {
+        super(System.err);
+    }
+
+    @Test
+    public void testMissingClass(Path outerBase) throws Exception {
+        Path src = outerBase.resolve("src");
+        tb.writeJavaFiles(src,
+                          "import java.util.Optional;\n" +
+                          "\n" +
+                          "abstract class B {\n" +
+                          "  abstract <M> Optional<M> g(F<M> p);\n" +
+                          "}\n",
+                          "interface F<M> {\n" +
+                          "  M u(A o);\n" +
+                          "}\n",
+                          "interface A {\n" +
+                          "  <T> T v(Class<? extends T> o);\n" +
+                          "}\n",
+                          "abstract class Test {\n" +
+                          "  abstract String f(Object proto);\n" +
+                          "  String test(B o) {\n" +
+                          "    return f(o.g((x) -> x.v(Object.class)).get());\n" +
+                          "  }\n" +
+                          "}\n");
+        Path classes = outerBase.resolve("classes");
+        Files.createDirectories(classes);
+        new JavacTask(tb)
+                .outdir(classes)
+                .files(src.resolve("B.java"), src.resolve("F.java"), src.resolve("A.java"))
+                .run()
+                .writeAll();
+        Files.delete(classes.resolve("A.class"));
+        StringWriter out = new StringWriter();
+        int ret = Main.compile(new String[] {"-d", classes.toString(),
+                                             "-classpath", classes.toString(),
+                                             "-XDrawDiagnostics",
+                                             src.resolve("Test.java").toString()
+                                            },
+                               new PrintWriter(out));
+
+        //check compilation output:
+        if (ret != 1) {
+            throw new AssertionError("Unexpected error code: " + ret);
+        }
+        String expectedOutput =
+            "Test.java:4:18: compiler.err.cant.access: A, (compiler.misc.class.file.not.found: A)\n" +
+            "1 error\n";
+        if (!expectedOutput.equals(out.toString().replace(System.lineSeparator(), "\n"))) {
+            throw new AssertionError("Unexpected output: " + out);
+        }
+
+        JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
+        try (StandardJavaFileManager fm = compiler.getStandardFileManager(null, null, null)) {
+            com.sun.source.util.JavacTask task = (com.sun.source.util.JavacTask)
+                    compiler.getTask(null,
+                                     null,
+                                     d -> {},
+                                     Arrays.asList("-d", classes.toString(),
+                                                   "-classpath", classes.toString()),
+                                     null,
+                                     fm.getJavaFileObjects(src.resolve("Test.java")));
+            CompilationUnitTree cut = task.parse().iterator().next();
+            task.analyze();
+            Trees trees = Trees.instance(task);
+            TypeMirror[] foundType = new TypeMirror[1];
+            new TreePathScanner<Void, Void>() {
+                @Override
+                public Void visitMemberSelect(MemberSelectTree node, Void p) {
+                    if (node.getIdentifier().contentEquals("v")) {
+                        foundType[0] = trees.getTypeMirror(getCurrentPath().getParentPath());
+                    }
+                    return super.visitMemberSelect(node, p);
+                }
+            }.scan(cut, null);
+
+            //check error type properties:
+            if (foundType[0] == null) {
+                throw new AssertionError("Did not find the expected type.");
+            }
+            if (foundType[0].getKind() != TypeKind.ERROR) {
+                throw new AssertionError("The type has an unexpected kind: " +
+                                         foundType[0].getKind());
+            }
+            TypeMirror enclosing = ((ErrorType) foundType[0]).getEnclosingType();
+            if (enclosing.getKind() != TypeKind.NONE) {
+                throw new AssertionError("The enclosing type has an unexpected kind: " +
+                                         enclosing.getKind());
+            }
+
+            //check that isAccessible does not crash on it:
+            trees.isAccessible(trees.getScope(new TreePath(cut)),
+                               (TypeElement) task.getTypes().asElement(foundType[0]));
+        }
+    }
+
+}