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 

     8 import com.sun.tools.classfile.ClassFile;

     9 import com.sun.tools.classfile.ConstantPoolException;

    10 import com.sun.tools.classfile.Method;

    11 import com.sun.tools.classfile.Attribute;

    12 import com.sun.tools.classfile.Code_attribute;

    13 import com.sun.tools.classfile.LineNumberTable_attribute;

    14 

    15 import java.io.IOException;

    16 import java.util.AbstractMap.SimpleEntry;

    17 import java.util.Arrays;

    18 import java.util.List;

    19 import java.util.Map.Entry;

    20 import java.util.Objects;

    21 import java.util.stream.Collectors;

    22 import java.util.stream.Stream;

    23 

    24 public 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 }