1 /*

     2  * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.

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

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  */

    23 

    24 /*

    25  * @test

    26  * @bug 8004727

    27  * @summary javac should generate method parameters correctly.

    28  */

    29 // key: opt.arg.parameters

    30 import com.sun.tools.classfile.*;

    31 import com.sun.tools.javac.file.JavacFileManager;

    32 import com.sun.tools.javac.main.Main;

    33 import com.sun.tools.javac.util.Context;

    34 import com.sun.tools.javac.util.Name;

    35 import com.sun.tools.javac.util.Names;

    36 import java.io.*;

    37 import javax.lang.model.element.*;

    38 import java.util.*;

    39 

    40 public class MethodParameters {

    41 

    42     static final String Foo_name = "Foo";

    43     static final String Foo_contents =

    44         "public class Foo {\n" +

    45         "  Foo() {}\n" +

    46         "  void foo0() {}\n" +

    47         "  void foo2(int j, int k) {}\n" +

    48         "}";

    49     static final String Bar_name = "Bar";

    50     static final String Bar_contents =

    51         "public class Bar {\n" +

    52         "  Bar(int i) {}" +

    53         "  Foo foo() { return new Foo(); }\n" +

    54         "}";

    55     static final String Baz_name = "Baz";

    56     static final String Baz_contents =

    57         "public class Baz {\n" +

    58         "  int baz;" +

    59         "  Baz(int i) {}" +

    60         "}";

    61     static final String Qux_name = "Qux";

    62     static final String Qux_contents =

    63         "public class Qux extends Baz {\n" +

    64         "  Qux(int i) { super(i); }" +

    65         "}";

    66     static final File classesdir = new File("methodparameters");

    67 

    68     public static void main(String... args) throws Exception {

    69         new MethodParameters().run();

    70     }

    71 

    72     void run() throws Exception {

    73         classesdir.mkdir();

    74         final File Foo_java =

    75             writeFile(classesdir, Foo_name + ".java", Foo_contents);

    76         final File Bar_java =

    77             writeFile(classesdir, Bar_name + ".java", Bar_contents);

    78         final File Baz_java =

    79             writeFile(classesdir, Baz_name + ".java", Baz_contents);

    80         System.err.println("Test compile with -parameter");

    81         compile("-parameters", "-d", classesdir.getPath(), Foo_java.getPath());

    82         // First test: make sure javac doesn't choke to death on

    83         // MethodParameter attributes

    84         System.err.println("Test compile with classfile containing MethodParameter attributes");

    85         compile("-parameters", "-d", classesdir.getPath(),

    86                 "-cp", classesdir.getPath(), Bar_java.getPath());

    87         System.err.println("Examine class foo");

    88         checkFoo();

    89         checkBar();

    90         System.err.println("Test debug information conflict");

    91         compile("-g", "-parameters", "-d", classesdir.getPath(),

    92                 "-cp", classesdir.getPath(), Baz_java.getPath());

    93         System.err.println("Introducing debug information conflict");

    94         Baz_java.delete();

    95         modifyBaz(false);

    96         System.err.println("Checking language model");

    97         inspectBaz();

    98         System.err.println("Permuting attributes");

    99         modifyBaz(true);

   100         System.err.println("Checking language model");

   101         inspectBaz();

   102 

   103         if(0 != errors)

   104             throw new Exception("MethodParameters test failed with " +

   105                                 errors + " errors");

   106     }

   107 

   108     void inspectBaz() throws Exception {

   109         final File Qux_java =

   110             writeFile(classesdir, Qux_name + ".java", Qux_contents);

   111         final String[] args = { "-XDsave-parameter-names", "-d",

   112                                 classesdir.getPath(),

   113                                 "-cp", classesdir.getPath(),

   114                                 Qux_java.getPath() };

   115         final StringWriter sw = new StringWriter();

   116         final PrintWriter pw = new PrintWriter(sw);

   117 

   118         // We need to be able to crack open javac and look at its data

   119         // structures.  We'll rig up a compiler instance, but keep its

   120         // Context, thus allowing us to get at the ClassReader.

   121         Context context = new Context();

   122         Main comp =  new Main("javac", pw);

   123         JavacFileManager.preRegister(context);

   124 

   125         // Compile Qux, which uses Baz.

   126         comp.compile(args, context);

   127         pw.close();

   128         final String out = sw.toString();

   129         if (out.length() > 0)

   130             System.err.println(out);

   131 

   132         // Now get the class reader, construct a name for Baz, and load it.

   133         com.sun.tools.javac.jvm.ClassReader cr =

   134             com.sun.tools.javac.jvm.ClassReader.instance(context);

   135         Name name = Names.instance(context).fromString(Baz_name);

   136 

   137         // Now walk down the language model and check the name of the

   138         // parameter.

   139         final Element baz = cr.loadClass(name);

   140         for (Element e : baz.getEnclosedElements()) {

   141             if (e instanceof ExecutableElement) {

   142                 final ExecutableElement ee = (ExecutableElement) e;

   143                 final List<? extends VariableElement> params =

   144                     ee.getParameters();

   145                 if (1 != params.size())

   146                     throw new Exception("Classfile Baz badly formed: wrong number of methods");

   147                 final VariableElement param = params.get(0);

   148                 if (!param.getSimpleName().contentEquals("baz")) {

   149                     errors++;

   150                     System.err.println("javac did not correctly resolve the metadata conflict, parameter's name reads as " + param.getSimpleName());

   151                 } else

   152                     System.err.println("javac did correctly resolve the metadata conflict");

   153             }

   154         }

   155     }

   156 

   157     void modifyBaz(boolean flip) throws Exception {

   158         final File Baz_class = new File(classesdir, Baz_name + ".class");

   159         final ClassFile baz = ClassFile.read(Baz_class);

   160         final int ind = baz.constant_pool.getUTF8Index("baz");

   161         MethodParameters_attribute mpattr = null;

   162         int mpind = 0;

   163         Code_attribute cattr = null;

   164         int cind = 0;

   165 

   166         // Find the indexes of the MethodParameters and the Code attributes

   167         if (baz.methods.length != 1)

   168             throw new Exception("Classfile Baz badly formed: wrong number of methods");

   169         if (!baz.methods[0].getName(baz.constant_pool).equals("<init>"))

   170             throw new Exception("Classfile Baz badly formed: method has name " +

   171                                 baz.methods[0].getName(baz.constant_pool));

   172         for (int i = 0; i < baz.methods[0].attributes.attrs.length; i++) {

   173             if (baz.methods[0].attributes.attrs[i] instanceof

   174                 MethodParameters_attribute) {

   175                 mpattr = (MethodParameters_attribute)

   176                     baz.methods[0].attributes.attrs[i];

   177                 mpind = i;

   178             } else if (baz.methods[0].attributes.attrs[i] instanceof

   179                        Code_attribute) {

   180                 cattr = (Code_attribute) baz.methods[0].attributes.attrs[i];

   181                 cind = i;

   182             }

   183         }

   184         if (null == mpattr)

   185             throw new Exception("Classfile Baz badly formed: no method parameters info");

   186         if (null == cattr)

   187             throw new Exception("Classfile Baz badly formed: no local variable table");

   188 

   189         int flags = mpattr.method_parameter_table[0].flags;

   190 

   191         // Alter the MethodParameters attribute, changing the name of

   192         // the parameter from i to baz.  This requires Black Magic...

   193         //

   194         // The (well-designed) classfile library (correctly) does not

   195         // allow us to mess around with the attribute data structures,

   196         // or arbitrarily generate new ones.

   197         //

   198         // Instead, we install a new subclass of Attribute that

   199         // hijacks the Visitor pattern and outputs the sequence of

   200         // bytes that we want.  This only works in this particular

   201         // instance, because we know we'll only every see one kind of

   202         // visitor.

   203         //

   204         // If anyone ever changes the makeup of the Baz class, or

   205         // tries to install some kind of visitor that gets run prior

   206         // to serialization, this will break.

   207         baz.methods[0].attributes.attrs[mpind] =

   208             new Attribute(mpattr.attribute_name_index,

   209                           mpattr.attribute_length) {

   210                 public <R, D> R accept(Visitor<R, D> visitor, D data) {

   211                     if (data instanceof ByteArrayOutputStream) {

   212                         ByteArrayOutputStream out =

   213                             (ByteArrayOutputStream) data;

   214                         out.write(1);

   215                         out.write((ind >> 8) & 0xff);

   216                         out.write(ind & 0xff);

   217                         out.write((flags >> 24) & 0xff);

   218                         out.write((flags >> 16) & 0xff);

   219                         out.write((flags >> 8) & 0xff);

   220                         out.write(flags & 0xff);

   221                     } else

   222                         throw new RuntimeException("Output stream is of type " + data.getClass() + ", which is not handled by this test.  Update the test and it should work.");

   223                     return null;

   224                 }

   225             };

   226 

   227         // Flip the code and method attributes.  This is for checking

   228         // that order doesn't matter.

   229         if (flip) {

   230             baz.methods[0].attributes.attrs[mpind] = cattr;

   231             baz.methods[0].attributes.attrs[cind] = mpattr;

   232         }

   233 

   234         new ClassWriter().write(baz, Baz_class);

   235     }

   236 

   237     // Run a bunch of structural tests on foo to make sure it looks right.

   238     void checkFoo() throws Exception {

   239         final File Foo_class = new File(classesdir, Foo_name + ".class");

   240         final ClassFile foo = ClassFile.read(Foo_class);

   241         for (int i = 0; i < foo.methods.length; i++) {

   242             System.err.println("Examine method Foo." + foo.methods[i].getName(foo.constant_pool));

   243             if (foo.methods[i].getName(foo.constant_pool).equals("foo2")) {

   244                 for (int j = 0; j < foo.methods[i].attributes.attrs.length; j++)

   245                     if (foo.methods[i].attributes.attrs[j] instanceof

   246                         MethodParameters_attribute) {

   247                         MethodParameters_attribute mp =

   248                             (MethodParameters_attribute)

   249                             foo.methods[i].attributes.attrs[j];

   250                         System.err.println("Foo.foo2 should have 2 parameters: j and k");

   251                         if (2 != mp.method_parameter_table_length)

   252                             error("expected 2 method parameter entries in foo2, got " +

   253                                   mp.method_parameter_table_length);

   254                         else if (!foo.constant_pool.getUTF8Value(mp.method_parameter_table[0].name_index).equals("j"))

   255                             error("expected first parameter to foo2 to be \"j\", got \"" +

   256                                   foo.constant_pool.getUTF8Value(mp.method_parameter_table[0].name_index) +

   257                                   "\" instead");

   258                         else if  (!foo.constant_pool.getUTF8Value(mp.method_parameter_table[1].name_index).equals("k"))

   259                             error("expected first parameter to foo2 to be \"k\", got \"" +

   260                                   foo.constant_pool.getUTF8Value(mp.method_parameter_table[1].name_index) +

   261                                   "\" instead");

   262                     }

   263             }

   264             else if (foo.methods[i].getName(foo.constant_pool).equals("<init>")) {

   265                 for (int j = 0; j < foo.methods[i].attributes.attrs.length; j++) {

   266                     if (foo.methods[i].attributes.attrs[j] instanceof

   267                         MethodParameters_attribute)

   268                         error("Zero-argument constructor shouldn't have MethodParameters");

   269                 }

   270             }

   271             else if (foo.methods[i].getName(foo.constant_pool).equals("foo0")) {

   272                 for (int j = 0; j < foo.methods[i].attributes.attrs.length; j++)

   273                     if (foo.methods[i].attributes.attrs[j] instanceof

   274                         MethodParameters_attribute)

   275                         error("Zero-argument method shouldn't have MethodParameters");

   276             }

   277             else

   278                 error("Unknown method " + foo.methods[i].getName(foo.constant_pool) + " showed up in class Foo");

   279         }

   280     }

   281 

   282     // Run a bunch of structural tests on Bar to make sure it looks right.

   283     void checkBar() throws Exception {

   284         final File Bar_class = new File(classesdir, Bar_name + ".class");

   285         final ClassFile bar = ClassFile.read(Bar_class);

   286         for (int i = 0; i < bar.methods.length; i++) {

   287             System.err.println("Examine method Bar." + bar.methods[i].getName(bar.constant_pool));

   288             if (bar.methods[i].getName(bar.constant_pool).equals("<init>")) {

   289                 for (int j = 0; j < bar.methods[i].attributes.attrs.length; j++)

   290                     if (bar.methods[i].attributes.attrs[j] instanceof

   291                         MethodParameters_attribute) {

   292                         MethodParameters_attribute mp =

   293                             (MethodParameters_attribute)

   294                             bar.methods[i].attributes.attrs[j];

   295                         System.err.println("Bar constructor should have 1 parameter: i");

   296                         if (1 != mp.method_parameter_table_length)

   297                             error("expected 1 method parameter entries in constructor, got " +

   298                                   mp.method_parameter_table_length);

   299                         else if (!bar.constant_pool.getUTF8Value(mp.method_parameter_table[0].name_index).equals("i"))

   300                             error("expected first parameter to foo2 to be \"i\", got \"" +

   301                                   bar.constant_pool.getUTF8Value(mp.method_parameter_table[0].name_index) +

   302                                   "\" instead");

   303                     }

   304             }

   305             else if (bar.methods[i].getName(bar.constant_pool).equals("foo")) {

   306                 for (int j = 0; j < bar.methods[i].attributes.attrs.length; j++) {

   307                     if (bar.methods[i].attributes.attrs[j] instanceof

   308                         MethodParameters_attribute)

   309                         error("Zero-argument constructor shouldn't have MethodParameters");

   310                 }

   311             }

   312         }

   313     }

   314 

   315     String compile(String... args) throws Exception {

   316         System.err.println("compile: " + Arrays.asList(args));

   317         StringWriter sw = new StringWriter();

   318         PrintWriter pw = new PrintWriter(sw);

   319         int rc = com.sun.tools.javac.Main.compile(args, pw);

   320         pw.close();

   321         String out = sw.toString();

   322         if (out.length() > 0)

   323             System.err.println(out);

   324         if (rc != 0)

   325             error("compilation failed, rc=" + rc);

   326         return out;

   327     }

   328 

   329     File writeFile(File dir, String path, String body) throws IOException {

   330         File f = new File(dir, path);

   331         f.getParentFile().mkdirs();

   332         FileWriter out = new FileWriter(f);

   333         out.write(body);

   334         out.close();

   335         return f;

   336     }

   337 

   338     void error(String msg) {

   339         System.err.println("Error: " + msg);

   340         errors++;

   341     }

   342 

   343     int errors;

   344 }