com.sun.tools.classfile.ClassWriter Java Examples

The following examples show how to use com.sun.tools.classfile.ClassWriter. You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. You may check out the related API usage on the sidebar.
Example #1
Source Project: openjdk-jdk9   Author: AdoptOpenJDK   File: BadClass.java    License: GNU General Public License v2.0 6 votes vote down vote up
public static void main(String... args) throws Exception {
    new File("d1").mkdir();
    new File("d2").mkdir();

    // Step 1. build an empty class with an interface
    makeClass("d1", "Empty.java", "abstract class Empty implements Readable {}");

    // Step 2. Modify classfile to have invalid constant pool index
    ClassFile cf = ClassFile.read(new File("d1","Empty.class"));
    cf.interfaces[0] = cf.constant_pool.size() + 10;
    ClassWriter cw = new ClassWriter();
    cw.write(cf, new File("d2","Empty.class"));

    // Step 3. Compile use of invalid class
    String result = makeClass("d2", "EmptyUse.java", "class EmptyUse { Empty e; }");
    if (!result.contains("compiler.misc.bad.class.file")) {
        System.out.println(result);
        throw new Exception("test failed");
    }
}
 
Example #2
Source Project: openjdk-jdk9   Author: AdoptOpenJDK   File: TestClassNameWarning.java    License: GNU General Public License v2.0 5 votes vote down vote up
/**
 * Test an invalid class, with this_class == 0.
 */
@Test
public void testNoNameClass(Path base) throws Exception {
    Path src = base.resolve("src");
    Path classes = Files.createDirectories(base.resolve("classes"));
    tb.writeJavaFiles(src, "class A { }");

    new JavacTask(tb)
            .outdir(classes.toString())
            .files(tb.findJavaFiles(src))
            .run()
            .writeAll();

    ClassFile cf = ClassFile.read(classes.resolve("A.class"));
    ClassFile cf2 = new ClassFile(
            cf.magic, cf.minor_version, cf.major_version, cf.constant_pool,
            cf.access_flags,
            0, // this_class,
            cf.super_class, cf.interfaces, cf.fields, cf.methods, cf.attributes);
    new ClassWriter().write(cf2, Files.newOutputStream(classes.resolve("Z.class")));

    List<String> log = new JavapTask(tb)
            .classpath(classes.toString())
            .classes("Z")
            .run()
            .writeAll()
            .getOutputLines(Task.OutputKind.DIRECT);

    checkOutput(log, true, "Warning:.*Z.class does not contain class Z");
}
 
Example #3
Source Project: openjdk-jdk9   Author: AdoptOpenJDK   File: IncubatingTest.java    License: GNU General Public License v2.0 5 votes vote down vote up
private void addModuleResolutionAttribute(Path classfile, int resolution_flags) throws Exception {
    ClassFile cf = ClassFile.read(classfile);
    Attributes attrs = cf.attributes;
    List<CPInfo> cpData = new ArrayList<>();
    cpData.add(null);
    for (CPInfo info : cf.constant_pool.entries()) {
        cpData.add(info);
        if (info.size() == 2)
            cpData.add(null);
    }
    cpData.add(new CONSTANT_Utf8_info(Attribute.ModuleResolution));
    ConstantPool newCP = new ConstantPool(cpData.toArray(new CPInfo[0]));
    ModuleResolution_attribute res = new ModuleResolution_attribute(newCP, resolution_flags);
    Map<String, Attribute> newAttributeMap = new HashMap<>(attrs.map);
    newAttributeMap.put(Attribute.ModuleResolution, res);
    Attributes newAttrs = new Attributes(newAttributeMap);
    ClassFile newCF = new ClassFile(cf.magic,
                                    cf.minor_version,
                                    cf.major_version,
                                    newCP,
                                    cf.access_flags,
                                    cf.this_class,
                                    cf.super_class,
                                    cf.interfaces,
                                    cf.fields,
                                    cf.methods,
                                    newAttrs);
    try (OutputStream out = Files.newOutputStream(classfile)) {
        new ClassWriter().write(newCF, out);
    }
}
 
Example #4
Source Project: openjdk-jdk9   Author: AdoptOpenJDK   File: OpenModulesTest.java    License: GNU General Public License v2.0 4 votes vote down vote up
@Test
public void testNonZeroOpensInOpen(Path base) throws Exception {
    Path m1 = base.resolve("m1x");
    tb.writeJavaFiles(m1,
                      "module m1x { opens api; }",
                      "package api; public class Api {}");
    Path classes = base.resolve("classes");
    Path m1Classes = classes.resolve("m1x");
    tb.createDirectories(m1Classes);

    new JavacTask(tb)
        .options("-XDrawDiagnostics")
        .outdir(m1Classes)
        .files(findJavaFiles(m1))
        .run(Expect.SUCCESS)
        .writeAll();

    Path miClass = m1Classes.resolve("module-info.class");
    ClassFile cf = ClassFile.read(miClass);
    Module_attribute module = (Module_attribute) cf.attributes.map.get(Attribute.Module);
    Module_attribute newModule = new Module_attribute(module.attribute_name_index,
                                                      module.module_name,
                                                      module.module_flags | Module_attribute.ACC_OPEN,
                                                      module.module_version_index,
                                                      module.requires,
                                                      module.exports,
                                                      module.opens,
                                                      module.uses_index,
                                                      module.provides);
    Map<String, Attribute> attrs = new HashMap<>(cf.attributes.map);

    attrs.put(Attribute.Module, newModule);

    Attributes newAttributes = new Attributes(attrs);
    ClassFile newClassFile = new ClassFile(cf.magic,
                                           cf.minor_version,
                                           cf.major_version,
                                           cf.constant_pool,
                                           cf.access_flags,
                                           cf.this_class,
                                           cf.super_class,
                                           cf.interfaces,
                                           cf.fields,
                                           cf.methods,
                                           newAttributes);

    try (OutputStream out = Files.newOutputStream(miClass)) {
        new ClassWriter().write(newClassFile, out);
    }

    Path test = base.resolve("test");
    tb.writeJavaFiles(test,
                      "package impl; public class Impl extends api.Api {}");
    Path testClasses = base.resolve("test-classes");
    tb.createDirectories(testClasses);

    List<String> log = new JavacTask(tb)
            .options("-XDrawDiagnostics",
                     "--module-path", classes.toString(),
                     "--add-modules", "m1x")
            .outdir(testClasses)
            .files(findJavaFiles(test))
            .run(Expect.FAIL)
            .writeAll()
            .getOutputLines(Task.OutputKind.DIRECT);

    List<String> expected = Arrays.asList(
            "- compiler.err.cant.access: m1x.module-info, "
                    + "(compiler.misc.bad.class.file.header: module-info.class, "
                    + "(compiler.misc.module.non.zero.opens: m1x))",
                                          "1 error");

    if (!expected.equals(log))
        throw new Exception("expected output not found: " + log);
}
 
Example #5
Source Project: jdk8u-jdk   Author: frohoff   File: RemoveMethods.java    License: GNU General Public License v2.0 4 votes vote down vote up
public static void main(String[] args) throws Exception {
    if (args.length < 2) {
        System.err.println("Usage: java RemoveMethods classfile output [method...]");
        System.exit(-1);
    }

    // class file to read
    Path input = Paths.get(args[0]);

    // class file to write, if directory then use the name of the input
    Path output = Paths.get(args[1]);
    if (Files.isDirectory(output))
        output = output.resolve(input.getFileName());

    // the methods to remove
    Set<String> methodsToRemove = new HashSet<>();
    int i = 2;
    while (i < args.length)
        methodsToRemove.add(args[i++]);

    // read class file
    ClassFile cf;
    try (InputStream in = Files.newInputStream(input)) {
         cf = ClassFile.read(in);
    }

    final int magic = cf.magic;
    final int major_version = cf.major_version;
    final int minor_version = cf.minor_version;
    final ConstantPool cp = cf.constant_pool;
    final AccessFlags access_flags = cf.access_flags;
    final int this_class = cf.this_class;
    final int super_class = cf.super_class;
    final int[] interfaces = cf.interfaces;
    final Field[] fields = cf.fields;
    final Attributes class_attrs = cf.attributes;

    // remove the requested methods, no signature check at this time
    Method[] methods = cf.methods;
    i = 0;
    while (i < methods.length) {
        Method m = methods[i];
        String name = m.getName(cp);
        if (methodsToRemove.contains(name)) {
            int len = methods.length;
            Method[] newMethods = new Method[len-1];
            if (i > 0)
                System.arraycopy(methods, 0, newMethods, 0, i);
            int after = methods.length - i - 1;
            if (after > 0)
                System.arraycopy(methods, i+1, newMethods, i, after);
            methods = newMethods;
            String paramTypes = m.descriptor.getParameterTypes(cp);
            System.out.format("Removed method %s%s from %s%n",
                name, paramTypes, cf.getName());
            continue;
        }
        i++;
    }

    // TBD, prune constant pool of entries that are no longer referenced

    // re-write class file
    cf = new ClassFile(magic, minor_version, major_version, cp, access_flags,
            this_class, super_class, interfaces, fields, methods, class_attrs);
    try (OutputStream out = Files.newOutputStream(output)) {
         new ClassWriter().write(cf, out);
    }
}
 
Example #6
Source Project: jdk8u-dev-jdk   Author: frohoff   File: RemoveMethods.java    License: GNU General Public License v2.0 4 votes vote down vote up
public static void main(String[] args) throws Exception {
    if (args.length < 2) {
        System.err.println("Usage: java RemoveMethods classfile output [method...]");
        System.exit(-1);
    }

    // class file to read
    Path input = Paths.get(args[0]);

    // class file to write, if directory then use the name of the input
    Path output = Paths.get(args[1]);
    if (Files.isDirectory(output))
        output = output.resolve(input.getFileName());

    // the methods to remove
    Set<String> methodsToRemove = new HashSet<>();
    int i = 2;
    while (i < args.length)
        methodsToRemove.add(args[i++]);

    // read class file
    ClassFile cf;
    try (InputStream in = Files.newInputStream(input)) {
         cf = ClassFile.read(in);
    }

    final int magic = cf.magic;
    final int major_version = cf.major_version;
    final int minor_version = cf.minor_version;
    final ConstantPool cp = cf.constant_pool;
    final AccessFlags access_flags = cf.access_flags;
    final int this_class = cf.this_class;
    final int super_class = cf.super_class;
    final int[] interfaces = cf.interfaces;
    final Field[] fields = cf.fields;
    final Attributes class_attrs = cf.attributes;

    // remove the requested methods, no signature check at this time
    Method[] methods = cf.methods;
    i = 0;
    while (i < methods.length) {
        Method m = methods[i];
        String name = m.getName(cp);
        if (methodsToRemove.contains(name)) {
            int len = methods.length;
            Method[] newMethods = new Method[len-1];
            if (i > 0)
                System.arraycopy(methods, 0, newMethods, 0, i);
            int after = methods.length - i - 1;
            if (after > 0)
                System.arraycopy(methods, i+1, newMethods, i, after);
            methods = newMethods;
            String paramTypes = m.descriptor.getParameterTypes(cp);
            System.out.format("Removed method %s%s from %s%n",
                name, paramTypes, cf.getName());
            continue;
        }
        i++;
    }

    // TBD, prune constant pool of entries that are no longer referenced

    // re-write class file
    cf = new ClassFile(magic, minor_version, major_version, cp, access_flags,
            this_class, super_class, interfaces, fields, methods, class_attrs);
    try (OutputStream out = Files.newOutputStream(output)) {
         new ClassWriter().write(cf, out);
    }
}