NullCheckLineNumberTest.java revision 4181:0426d4e746af 
1/*
2 * @test /nodynamiccopyright/
3 * @bug 8172880
4 * @summary  Wrong LineNumberTable for synthetic null checks
5 * @modules jdk.jdeps/com.sun.tools.classfile
6 */
7
8import com.sun.tools.classfile.ClassFile;
9import com.sun.tools.classfile.ConstantPoolException;
10import com.sun.tools.classfile.Method;
11import com.sun.tools.classfile.Attribute;
12import com.sun.tools.classfile.Code_attribute;
13import com.sun.tools.classfile.LineNumberTable_attribute;
14
15import java.io.IOException;
16import java.util.AbstractMap.SimpleEntry;
17import java.util.Arrays;
18import java.util.List;
19import java.util.Map.Entry;
20import java.util.Objects;
21import java.util.stream.Collectors;
22import java.util.stream.Stream;
23
24public class NullCheckLineNumberTest {
25
26    //test data:
27    static class Test {
28
29        public Test() {
30            String a = "", b = null;
31
32            Stream.of("x")
33                  .filter(a::equals)
34                  .filter(b::equals)
35                  .count();
36        }
37
38    }
39
40    public static void main(String[] args) throws Exception {
41        List<Entry> actualEntries = findEntries();
42        List<Entry> expectedEntries = List.of(
43                new SimpleEntry<>(29, 0),
44                new SimpleEntry<>(30, 4),
45                new SimpleEntry<>(32, 9),
46                new SimpleEntry<>(33, 16),
47                new SimpleEntry<>(34, 32),
48                new SimpleEntry<>(35, 46),
49                new SimpleEntry<>(36, 52)
50        );
51        if (!Objects.equals(actualEntries, expectedEntries)) {
52            error(String.format("Unexpected LineNumberTable: %s", actualEntries.toString()));
53        }
54
55        try {
56            new Test();
57        } catch (NullPointerException npe) {
58            if (Arrays.stream(npe.getStackTrace())
59                      .noneMatch(se -> se.getFileName().contains("NullCheckLineNumberTest") &&
60                                       se.getLineNumber() == 34)) {
61                throw new AssertionError("Should go through line 34!");
62            }
63        }
64    }
65
66    static List<Entry> findEntries() throws IOException, ConstantPoolException {
67        ClassFile self = ClassFile.read(NullCheckLineNumberTest.Test.class.getResourceAsStream("NullCheckLineNumberTest$Test.class"));
68        for (Method m : self.methods) {
69            if ("<init>".equals(m.getName(self.constant_pool))) {
70                Code_attribute code_attribute = (Code_attribute)m.attributes.get(Attribute.Code);
71                for (Attribute at : code_attribute.attributes) {
72                    if (Attribute.LineNumberTable.equals(at.getName(self.constant_pool))) {
73                        return Arrays.stream(((LineNumberTable_attribute)at).line_number_table)
74                                     .map(e -> new SimpleEntry<> (e.line_number, e.start_pc))
75                                     .collect(Collectors.toList());
76                    }
77                }
78            }
79        }
80        return null;
81    }
82
83    static void error(String msg) {
84        throw new AssertionError(msg);
85    }
86
87}
88