8142931: java compiler: type erasure doesn't work since 9-b28

Reinstate pre JDK-8055054 behavior with respect to erasing wildcard types.

Reviewed-by: mcimadamore

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

@@ -2181,6 +2181,12 @@ public class Types {
                 }
             }
 
+            @Override
+            public Type visitWildcardType(WildcardType t, Boolean recurse) {
+                Type erased = erasure(wildUpperBound(t), recurse);
+                return combineMetadata(erased, t);
+            }
+
             @Override
             public Type visitClassType(ClassType t, Boolean recurse) {
                 Type erased = t.tsym.erasure(Types.this);

langtools/test/tools/javac/processing/T8142931.java

@@ -0,0 +1,101 @@
+/*
+ * Copyright (c) 2015, 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 8142931
+ * @summary java compiler: type erasure doesn't work since 9-b28
+ * @modules jdk.compiler/com.sun.tools.javac.api
+ *          jdk.compiler/com.sun.tools.javac.file
+ */
+
+import java.io.*;
+import java.util.*;
+import javax.annotation.processing.*;
+import javax.lang.model.*;
+import javax.lang.model.element.*;
+import javax.lang.model.util.ElementFilter;
+import javax.lang.model.type.TypeMirror;
+import javax.lang.model.type.DeclaredType;
+import javax.tools.*;
+import com.sun.source.util.*;
+import com.sun.tools.javac.api.*;
+
+@SupportedAnnotationTypes("*")
+public class T8142931 extends AbstractProcessor {
+
+    public java.util.List<? extends javax.xml.namespace.QName> f0;
+
+    public static void main(String... args) throws IOException {
+        String testSrc = System.getProperty("test.src", ".");
+        String testClasses = System.getProperty("test.classes");
+        JavacTool tool = JavacTool.create();
+        MyDiagListener dl = new MyDiagListener();
+        try (StandardJavaFileManager fm = tool.getStandardFileManager(dl, null, null)) {
+            Iterable<? extends JavaFileObject> files =
+                fm.getJavaFileObjectsFromFiles(Arrays.asList(new File(testSrc, T8142931.class.getName()+".java")));
+            Iterable<String> opts = Arrays.asList("-proc:only",
+                                                  "-processor", "T8142931",
+                                                  "-processorpath", testClasses);
+            StringWriter out = new StringWriter();
+            JavacTask task = tool.getTask(out, fm, dl, opts, null, files);
+            task.call();
+            String s = out.toString();
+            System.err.print(s);
+            System.err.println(dl.count + " diagnostics; " + s.length() + " characters");
+            if (dl.count != 0 || s.length() != 0)
+                throw new AssertionError("unexpected output from compiler");
+        }
+    }
+
+    @Override
+    public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {
+        Set<? extends Element> set = roundEnv.getRootElements();
+        for (Element element : set) {
+            Collection<VariableElement> fields = ElementFilter.fieldsIn(((TypeElement) element).getEnclosedElements());
+            for (VariableElement field : fields) {
+                TypeMirror listType = field.asType();
+                List<? extends TypeMirror> typeArgs = ((DeclaredType) listType).getTypeArguments();
+                TypeMirror arg = typeArgs.get(0);
+                String erasure = processingEnv.getTypeUtils().erasure(arg).toString();
+                if (!erasure.equals("javax.xml.namespace.QName"))
+                    throw new AssertionError("Wrong Erasure: " + erasure);
+            }
+        }
+        return false;
+    }
+
+    @Override
+    public SourceVersion getSupportedSourceVersion() {
+        return SourceVersion.latest();
+    }
+
+    static class MyDiagListener implements DiagnosticListener {
+        public void report(Diagnostic d) {
+            System.err.println(d);
+            count++;
+        }
+
+        public int count;
+    }
+}