AbstractMethodError Due to Incorrect Handling of Private Method #964
Description
Description
我们发现同一个测试用例在不同的OpenJDK Verison上的结果不同，具体而言JDK8抛出IllegalAccessError ，JDK11、17、21抛出AbstractMethodError。
Steps to Reproduce
首先执行下述的Java代码得到测试用例：
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
public class BytecodeUtil {
public static void main(String args[]) {
// create package
String baseDir = "./your_dir"; // your base dir
String packageName = "P0";
File folder = new File(baseDir + "/" + packageName);
folder.mkdirs();
String P0_I0_bytecodeInStr = "CAFEBABE00000034000F01000550302F49300700010100106A6176612F6C616E672F4F626A6563740700030100016D01001528294C6A6176612F6C616E672F496E74656765723B0100116A6176612F6C616E672F496E746567657207000703000000000100063C696E69743E010004284929560C000A000B0A0008000C010004436F64650601000200040000000000010001000500060001000E00000016000300010000000ABB0008591209B7000DB0000000000000" ;
String P0_C1_bytecodeInStr = "CAFEBABE00000034000E01000550302F43310700010100106A6176612F6C616E672F4F626A65637407000301000550302F493007000501000550302F49320700070100063C696E69743E0100032829560C0009000A0A0004000B010004436F64650021000200040002000600080000000100010009000A0001000D0000001100010001000000052AB7000CB1000000000000" ;
String P0_Helper_bytecodeInStr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
String P0_I2_bytecodeInStr = "CAFEBABE00000034000F01000550302F49320700010100106A6176612F6C616E672F4F626A6563740700030100016D01001528294C6A6176612F6C616E672F496E74656765723B0100116A6176612F6C616E672F496E746567657207000703000000020100063C696E69743E010004284929560C000A000B0A0008000C010004436F64650601000200040000000000010001000500060001000E00000016000300010000000ABB0008591209B7000DB0000000000000" ;
String P0_C3_bytecodeInStr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
String P0_C4_bytecodeInStr = "CAFEBABE00000034001401000550302F43340700010100106A6176612F6C616E672F4F626A65637407000301000550302F49300700050100063C696E69743E0100032829560C000700080A000400090100016D01001528294C6A6176612F6C616E672F496E74656765723B0100116A6176612F6C616E672F496E746567657207000D0300000004010004284929560C000700100A000E0011010004436F64650021000200040001000600000002000100070008000100130000001100010001000000052AB7000AB1000000000002000B000C0001001300000016000300010000000ABB000E59120FB70012B0000000000000" ;
String P0_C5_bytecodeInStr = "CAFEBABE00000034000A01000550302F433507000101000550302F43340700030100063C696E69743E0100032829560C000500060A00040007010004436F6465002100020004000000000001000100050006000100090000001100010001000000052AB70008B1000000000000" ;
try (FileOutputStream fos = new FileOutputStream(folder.getAbsolutePath() + "/" + "I0.class")) {
byte[] P0_I0_bytecode = hexStringToByteArray(P0_I0_bytecodeInStr);
fos.write(P0_I0_bytecode);
} catch (IOException e) {
e.printStackTrace();
}
try (FileOutputStream fos = new FileOutputStream(folder.getAbsolutePath() + "/" + "C1.class")) {
byte[] P0_I0_bytecode = hexStringToByteArray(P0_C1_bytecodeInStr);
fos.write(P0_I0_bytecode);
} catch (IOException e) {
e.printStackTrace();
}
try (FileOutputStream fos = new FileOutputStream(folder.getAbsolutePath() + "/" + "Helper.class")) {
byte[] P0_Helper_bytecode = hexStringToByteArray(P0_Helper_bytecodeInStr);
fos.write(P0_Helper_bytecode);
} catch (IOException e) {
e.printStackTrace();
}
try (FileOutputStream fos = new FileOutputStream(folder.getAbsolutePath() + "/" + "I2.class")) {
byte[] P0_I2_bytecode = hexStringToByteArray(P0_I2_bytecodeInStr);
fos.write(P0_I2_bytecode);
} catch (IOException e) {
e.printStackTrace();
}
try (FileOutputStream fos = new FileOutputStream(folder.getAbsolutePath() + "/" + "C3.class")) {
byte[] P0_C3_bytecode = hexStringToByteArray(P0_C3_bytecodeInStr);
fos.write(P0_C3_bytecode);
} catch (IOException e) {
e.printStackTrace();
}
try (FileOutputStream fos = new FileOutputStream(folder.getAbsolutePath() + "/" + "C4.class")) {
byte[] P0_C4_bytecode = hexStringToByteArray(P0_C4_bytecodeInStr);
fos.write(P0_C4_bytecode);
} catch (IOException e) {
e.printStackTrace();
}
try (FileOutputStream fos = new FileOutputStream(folder.getAbsolutePath() + "/" + "C5.class")) {
byte[] P0_C5_bytecode = hexStringToByteArray(P0_C5_bytecodeInStr);
fos.write(P0_C5_bytecode);
} catch (IOException e) {
e.printStackTrace();
}
}
public static byte[] hexStringToByteArray(String hexString) {
int length = hexString.length();
byte[] byteArray = new byte[length / 2];
for (int i = 0; i < length; i += 2) {
int byteValue = Integer.parseInt(hexString.substring(i, i + 2), 16);
byteArray[i / 2] = (byte) byteValue;
}
return byteArray;
}
}可以根据你的需要修改路径。
复现：
>>> path_to_jdk8/bin/java -cp . P0.C3
>>> path_to_jdk11/bin/java -cp . P0.C3
>>> path_to_jdk17/bin/java -cp . P0.C3
>>> path_to_jdk21/bin/java -cp . P0.C3
实际结果：
jdk8:
Exception in thread "main" java.lang.IllegalAccessError: P0.C5.m()Ljava/lang/Integer;
at P0.C3.test(Unknown Source)
at P0.C3.main(Unknown Source)
jdk11:
Exception in thread "main" java.lang.AbstractMethodError: Receiver class P0.C5 does not define or inherit an implementation of the resolved method 'java.lang.Integer m()' of interface P0.I0.
at P0.C3.test(Unknown Source)
at P0.C3.main(Unknown Source)
jdk17:
Exception in thread "main" java.lang.AbstractMethodError: Receiver class P0.C5 does not define or inherit an implementation of the resolved method 'java.lang.Integer m()' of interface P0.I0.
at P0.C3.test(Unknown Source)
at P0.C3.main(Unknown Source)
jdk21:
Exception in thread "main" java.lang.AbstractMethodError: Receiver class P0.C5 does not define or inherit an implementation of the resolved method 'java.lang.Integer m()' of interface P0.I0.
at P0.C3.test(Unknown Source)
at P0.C3.main(Unknown Source)
Expected behavior
根据上述的执行结果，我们首先使用javap将P0.C3反汇编，得到结果：
Classfile /D:/Lab/TestJDoc/JSmith-main/your_dir/P0/C3.class
Last modified May 12, 2025; size 539 bytes
MD5 checksum dbff33781d5155f4f302757476bf08e2
public class P0.C3 implements P0.I0
minor version: 0
major version: 52
flags: ACC_PUBLIC, ACC_SUPER
Constant pool:
#1 = Utf8 P0/C3
#2 = Class #1 // P0/C3
#3 = Utf8 java/lang/Object
#4 = Class #3 // java/lang/Object
#5 = Utf8 P0/I0
#6 = Class #5 // P0/I0
#7 = Utf8 <init>
#8 = Utf8 ()V
#9 = NameAndType #7:#8 // "<init>":()V
#10 = Methodref #4.#9 // java/lang/Object."<init>":()V
#11 = Utf8 test
#12 = Utf8 ()Ljava/lang/Integer;
#13 = Utf8 P0/Helper
#14 = Class #13 // P0/Helper
#15 = Utf8 getC5
#16 = Utf8 ()LP0/C5;
#17 = NameAndType #15:#16 // getC5:()LP0/C5;
#18 = Methodref #14.#17 // P0/Helper.getC5:()LP0/C5;
#19 = Utf8 m
#20 = NameAndType #19:#12 // m:()Ljava/lang/Integer;
#21 = InterfaceMethodref #6.#20 // P0/I0.m:()Ljava/lang/Integer;
#22 = Utf8 main
#23 = Utf8 ([Ljava/lang/String;)V
#24 = NameAndType #11:#12 // test:()Ljava/lang/Integer;
#25 = Methodref #2.#24 // P0/C3.test:()Ljava/lang/Integer;
#26 = Utf8 java/lang/System
#27 = Class #26 // java/lang/System
#28 = Utf8 out
#29 = Utf8 Ljava/io/PrintStream;
#30 = NameAndType #28:#29 // out:Ljava/io/PrintStream;
#31 = Fieldref #27.#30 // java/lang/System.out:Ljava/io/PrintStream;
#32 = Utf8 Return value:
#33 = String #32 // Return value:
#34 = Utf8 java/io/PrintStream
#35 = Class #34 // java/io/PrintStream
#36 = Utf8 print
#37 = Utf8 (Ljava/lang/String;)V
#38 = NameAndType #36:#37 // print:(Ljava/lang/String;)V
#39 = Methodref #35.#38 // java/io/PrintStream.print:(Ljava/lang/String;)V
#40 = Utf8 println
#41 = Utf8 (Ljava/lang/Object;)V
#42 = NameAndType #40:#41 // println:(Ljava/lang/Object;)V
#43 = Methodref #35.#42 // java/io/PrintStream.println:(Ljava/lang/Object;)V
#44 = Utf8 Code
{
public P0.C3();
descriptor: ()V
flags: ACC_PUBLIC
Code:
stack=1, locals=1, args_size=1
0: aload_0
1: invokespecial #10 // Method java/lang/Object."<init>":()V
4: return
public static java.lang.Integer test();
descriptor: ()Ljava/lang/Integer;
flags: ACC_PUBLIC, ACC_STATIC
Code:
stack=1, locals=1, args_size=0
0: invokestatic #18 // Method P0/Helper.getC5:()LP0/C5;
3: astore_0
4: aload_0
5: invokeinterface #21, 1 // InterfaceMethod P0/I0.m:()Ljava/lang/Integer;
10: areturn
public static void main(java.lang.String[]);
descriptor: ([Ljava/lang/String;)V
flags: ACC_PUBLIC, ACC_STATIC
Code:
stack=3, locals=2, args_size=1
0: invokestatic #25 // Method test:()Ljava/lang/Integer;
3: astore_1
4: getstatic #31 // Field java/lang/System.out:Ljava/io/PrintStream;
7: dup
8: ldc #33 // String Return value:
10: invokevirtual #39 // Method java/io/PrintStream.print:(Ljava/lang/String;)V
13: aload_1
14: invokevirtual #43 // Method java/io/PrintStream.println:(Ljava/lang/Object;)V
17: return
}
我们观察到，在 P0\C3.test() 中对 var0.m() 的调用使用了 invokeinterface。我们以V11为例，根据 Java SE 11 JVM 规范，invokeinterface 指令指出：“指定的接口方法会被解析（§5.4.3.4）。”此外，§5.4.3.4 规定：“否则，如果 C 声明了一个与接口方法引用指定的名称和描述符相匹配的方法，则方法查找成功。”基于此，解析出的接口方法是 I0.m()。
进入方法选择阶段（§5.4.6），已解析的方法 mR 是 I0.m()，类 C 是 C5。根据 §5.4.6 的规则：“如果 C 包含一个可以覆盖 mR（§5.4.5）的实例方法 m，则 m 即为被选择的方法。”由于 C5 没有声明这样的方法，流程继续执行下一条规则：“否则，如果 C 有超类，则从 C 的直接超类开始，沿着超类链向上搜索，查找可以覆盖 mR 的实例方法声明，直到找到方法或不再有超类为止。如果找到方法，则该方法即为被选择的方法。”然而，C5 的超类 C4 中的方法是 private 的，无法覆盖 I0.m()，因此这一步也失败了。
于是，流程进入最后一条规则：“否则，确定 C 的最具体超接口方法（§5.4.3.3）。如果恰好有一个方法与 mR 的名称和描述符匹配，并且不是 abstract 的，则该方法即为被选择的方法。”根据 §5.4.3.3，C5 的最具体超接口方法只有 I0.m()，它是非抽象的。因此，被选择的方法是 I0.m()。
回到 invokeinterface 指令，规范指出：“否则，如果被选择的方法既不是 public 也不是 private，则 invokeinterface 抛出 IllegalAccessError。”因此，结果应该是抛出 IllegalAccessError，而不是 AbstractMethodError。类似地，V17和V21也应抛出IAE而不是AME。
JDK version
openjdk version "1.8.0_462"
OpenJDK Runtime Environment (Alibaba Dragonwell Standard Edition 8.26.25) (build 1.8.0_462-b01)
OpenJDK 64-Bit Server VM (Alibaba Dragonwell Standard Edition 8.26.25) (build 25.462-b01, mixed mode)
openjdk version "11.0.28.24" 2025-07-15
OpenJDK Runtime Environment (Alibaba Dragonwell Standard Edition)-11.0.28.24+6-GA (build 11.0.28.24+6)
OpenJDK 64-Bit Server VM (Alibaba Dragonwell Standard Edition)-11.0.28.24+6-GA (build 11.0.28.24+6, mixed mode)
openjdk version "17.0.16" 2025-07-15
OpenJDK Runtime Environment (Alibaba Dragonwell Standard Edition)-17.0.16.0.17+8-GA (build 17.0.16+8)
OpenJDK 64-Bit Server VM (Alibaba Dragonwell Standard Edition)-17.0.16.0.17+8-GA (build 17.0.16+8, mixed mode, sharing)
openjdk version "21.0.8.0.8" 2025-07-15
OpenJDK Runtime Environment (Alibaba Dragonwell Standard Edition)-21.0.8.0.8+9-GA (build 21.0.8.0.8)
OpenJDK 64-Bit Server VM (Alibaba Dragonwell Standard Edition)-21.0.8.0.8+9-GA (build 21.0.8.0.8, mixed mode, sharing)
Execution environment
OS:
Operating System Name: Linux
Operating System Architecture: amd64
Operating System Version: 4.15.0-45-generic