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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

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 * 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

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 * questions.

 */

/*

 * @test

 * @bug 8013789

 * @summary Compiler should emit bridges in interfaces

 * @library /tools/javac/lib

 *          jdk.compiler/com.sun.tools.javac.code

 *          jdk.compiler/com.sun.tools.javac.util

 * @build JavacTestingAbstractProcessor BridgeHarness

 * @run main BridgeHarness

 */

import com.sun.source.util.JavacTask;

import com.sun.tools.classfile.AccessFlags;

import com.sun.tools.classfile.ClassFile;

import com.sun.tools.classfile.ConstantPool;

import com.sun.tools.classfile.ConstantPoolException;

import com.sun.tools.classfile.Method;

import com.sun.tools.javac.code.Symbol.ClassSymbol;

import com.sun.tools.javac.util.List;

import java.io.File;

import java.io.InputStream;

import java.util.Arrays;

import java.util.Collections;

import java.util.HashMap;

import java.util.Map;

import java.util.Set;

import javax.annotation.processing.RoundEnvironment;

import javax.annotation.processing.SupportedAnnotationTypes;

import javax.lang.model.element.Element;

import javax.lang.model.element.TypeElement;

import javax.tools.JavaCompiler;

import javax.tools.JavaFileObject;

import javax.tools.StandardJavaFileManager;

import javax.tools.ToolProvider;

import static javax.tools.StandardLocation.*;

public class BridgeHarness {

    /** number of errors found (must be zero for the test to pass) */

    static int nerrors = 0;

    /** the (shared) Java compiler used for compiling the tests */

    static final JavaCompiler comp = ToolProvider.getSystemJavaCompiler();

    /** the (shared) file manager used by the compiler */

    static final StandardJavaFileManager fm = comp.getStandardFileManager(null, null, null);

    public static void main(String[] args) throws Exception {

        try {

            //set sourcepath

            fm.setLocation(SOURCE_PATH,

                    Arrays.asList(new File(System.getProperty("test.src"), "tests")));

            //set output (-d)

            fm.setLocation(javax.tools.StandardLocation.CLASS_OUTPUT,

                    Arrays.asList(new File(System.getProperty("user.dir"))));

            for (JavaFileObject jfo : fm.list(SOURCE_PATH, "", Collections.singleton(JavaFileObject.Kind.SOURCE), true)) {

                //for each source, compile and check against annotations

                new BridgeHarness(jfo).compileAndCheck();

            }

            //if there were errors, fail

            if (nerrors > 0) {

                throw new AssertionError("Errors were found");

            }

        } finally {

            fm.close();

        }

    }

    /* utility methods */

    /**

     * Remove an element from a list

     */

    static <Z> List<Z> drop(List<Z> lz, Z z) {

        if (lz.head == z) {

            return drop(lz.tail, z);

        } else if (lz.isEmpty()) {

            return lz;

        } else {

            return drop(lz.tail, z).prepend(lz.head);

        }

    }

    /**

     * return a string representation of a bytecode method

     */

    static String descriptor(Method m, ConstantPool cp) throws ConstantPoolException {

        return m.getName(cp) + m.descriptor.getValue(cp);

    }

    /* test harness */

    /** Test file to be compiled */

    JavaFileObject jfo;

    /** Mapping between class name and list of bridges in class with that name */

    Map<String, List<Bridge>> bridgesMap = new HashMap<String, List<Bridge>>();

    protected BridgeHarness(JavaFileObject jfo) {

        this.jfo = jfo;

    }

    /**

     * Compile a test using a custom annotation processor and check the generated

     * bytecode against discovered annotations.

     */

    protected void compileAndCheck() throws Exception {

        JavacTask ct = (JavacTask)comp.getTask(null, fm, null, null, null, Arrays.asList(jfo));

        ct.setProcessors(Collections.singleton(new BridgeFinder()));

        for (JavaFileObject jfo : ct.generate()) {

            checkBridges(jfo);

        }

    }

    /**

     * Check that every bridge in the generated classfile has a matching bridge

     * annotation in the bridge map

     */

    protected void checkBridges(JavaFileObject jfo) {

        try (InputStream is = jfo.openInputStream()) {

            ClassFile cf = ClassFile.read(is);

            System.err.println("checking: " + cf.getName());

            List<Bridge> bridgeList = bridgesMap.get(cf.getName());

            if (bridgeList == null) {

                //no bridges - nothing to check;

                bridgeList = List.nil();

            }

            for (Method m : cf.methods) {

                if (m.access_flags.is(AccessFlags.ACC_SYNTHETIC | AccessFlags.ACC_BRIDGE)) {

                    //this is a bridge - see if there's a match in the bridge list

                    Bridge match = null;

                    for (Bridge b : bridgeList) {

                        if (b.value().equals(descriptor(m, cf.constant_pool))) {

                            match = b;

                            break;

                        }

                    }

                    if (match == null) {

                        error("No annotation for bridge method: " + descriptor(m, cf.constant_pool));

                    } else {

                        bridgeList = drop(bridgeList, match);

                    }

                }

            }

            if (bridgeList.nonEmpty()) {

                error("Redundant bridge annotation found: " + bridgeList.head.value());

            }

        } catch (Exception e) {

            e.printStackTrace();

            throw new Error("error reading " + jfo.toUri() +": " + e);

        }

    }

    /**

     * Log an error

     */

    protected void error(String msg) {

        nerrors++;

        System.err.printf("Error occurred while checking file: %s\nreason: %s\n", jfo.getName(), msg);

    }

    /**

     * This annotation processor is used to populate the bridge map with the

     * contents of the annotations that are found on the tests being compiled

     */

    @SupportedAnnotationTypes({"Bridges","Bridge"})

    class BridgeFinder extends JavacTestingAbstractProcessor {

        @Override

        public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {

            if (roundEnv.processingOver())

                return true;

            TypeElement bridgeAnno = elements.getTypeElement("Bridge");

            TypeElement bridgesAnno = elements.getTypeElement("Bridges");

            //see if there are repeated annos

            for (Element elem: roundEnv.getElementsAnnotatedWith(bridgesAnno)) {

                List<Bridge> bridgeList = List.nil();

                Bridges bridges = elem.getAnnotation(Bridges.class);

                for (Bridge bridge : bridges.value()) {

                    bridgeList = bridgeList.prepend(bridge);

                }

                bridgesMap.put(((ClassSymbol)elem).flatname.toString(), bridgeList);

            }

            //see if there are non-repeated annos

            for (Element elem: roundEnv.getElementsAnnotatedWith(bridgeAnno)) {

                Bridge bridge = elem.getAnnotation(Bridge.class);

                bridgesMap.put(((ClassSymbol)elem).flatname.toString(),

                        List.of(bridge));

            }

            return true;

        }

    }

}