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3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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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  *
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23 
24 /*
25  * @test
26  * @bug 6999210
27  * @summary javac should be able to warn of anomalous conditions in classfiles
28  * @modules jdk.compiler
29  */
30 
31 import java.io.*;
32 import java.util.*;
33 
34 public class T6999210 {
main(String... args)35     public static void main(String... args) throws Exception {
36         new T6999210().run();
37     }
38 
run()39     void run() throws Exception {
40         File srcDir = new File("src");
41         File classesDir = new File("classes");
42         classesDir.mkdirs();
43 
44         File c_java = writeFile(srcDir, "C.java", "class C<T> { }");
45         compile("-d", classesDir.getPath(), c_java.getPath());
46         File c_class = new File(classesDir, "C.class");
47         setMajorVersion(c_class, 48);
48         File d_java = writeFile(srcDir, "D.java", "class D { C c; }");
49 
50         // verify no warning if -Xlint:classfile not enabled
51         String out1 = compile(
52             "-d", classesDir.getPath(),
53             "-classpath", classesDir.getPath(),
54             d_java.getPath());
55         if (out1.length() > 0)
56             error("unexpected output from javac");
57 
58         // sanity check of warning when -XDrawDiagnostics not used
59         String out2 = compile(
60             "-d", classesDir.getPath(),
61             "-classpath", classesDir.getPath(),
62             "-Xlint:classfile",
63             d_java.getPath());
64         if (!out2.contains("[classfile]"))
65             error("expected output \"[classfile]\" not found");
66 
67         // check specific details, using -XDrawDiagnostics
68         String out3 = compile(
69             "-d", classesDir.getPath(),
70             "-classpath", classesDir.getPath(),
71             "-Xlint:classfile", "-XDrawDiagnostics",
72             d_java.getPath());
73         String expect = "C.class:-:-: compiler.warn.future.attr: Signature, 49, 0, 48, 0";
74         if (!out3.contains(expect))
75             error("expected output \"" + expect + "\" not found");
76 
77         if (errors > 0)
78             throw new Exception(errors + " errors occurred");
79     }
80 
compile(String... args)81     String compile(String... args) throws Exception {
82         System.err.println("compile: " + Arrays.asList(args));
83         StringWriter sw = new StringWriter();
84         PrintWriter pw = new PrintWriter(sw);
85         int rc = com.sun.tools.javac.Main.compile(args, pw);
86         pw.close();
87         String out = sw.toString();
88         if (out.length() > 0)
89             System.err.println(out);
90         if (rc != 0)
91             throw new Exception("compilation failed, rc=" + rc);
92         return out;
93     }
94 
setMajorVersion(File f, int major)95     void setMajorVersion(File f, int major) throws IOException {
96         int len = (int) f.length();
97         byte[] data = new byte[len];
98         try (DataInputStream in = new DataInputStream(new FileInputStream(f))) {
99             in.readFully(data);
100         }
101         // u4 magic
102         // u2 minor
103         data[6] = (byte) (major >> 8);
104         data[7] = (byte) (major & 0xff);
105         try (FileOutputStream out = new FileOutputStream(f)) {
106             out.write(data);
107         }
108     }
109 
writeFile(File dir, String path, String body)110     File writeFile(File dir, String path, String body) throws IOException {
111         File f = new File(dir, path);
112         f.getParentFile().mkdirs();
113         try (FileWriter out = new FileWriter(f)) {
114             out.write(body);
115         }
116         return f;
117     }
118 
error(String msg)119     void error(String msg) {
120         System.err.println("Error: " + msg);
121         errors++;
122     }
123 
124     int errors;
125 }
126