Java .class file reader for Java SE 8 and virtual machine for a subset of the JVM instruction set.
make
To run a Java 8 class file, use the i flag.
❯ ./main samples/MemoizedFibonacci i
memoFib(0)
0
memoFib(1)
1
memoFib(2)
1
memoFib(3)
2
memoFib(10)
55
memoFib(25)
75025
To print information about a Java class file, use the le flag.
❯ ./main samples/PrintInt le
class PrintInt
minor version: 0
major version: 52
J2SE 8.0
flags: ACC_PUBLIC ACC_SUPER
Constant pool:
#1 = Methodref java/lang/Object.<init>:()V (#5.#14)
#2 = Fieldref java/lang/System.out:Ljava/io/PrintStream; (#15.#16)
#3 = Methodref java/io/PrintStream.println:(I)V (#17.#18)
#4 = Class PrintInt (#19)
#5 = Class java/lang/Object (#20)
#6 = Utf8: <init>
#7 = Utf8: ()V
#8 = Utf8: Code
#9 = Utf8: LineNumberTable
#10 = Utf8: main
#11 = Utf8: ([Ljava/lang/String;)V
#12 = Utf8: SourceFile
#13 = Utf8: PrintInt.java
#14 = NameAndType <init>:()V (#6:#7)
#15 = Class java/lang/System (#21)
#16 = NameAndType out:Ljava/io/PrintStream; (#22:#23)
#17 = Class java/io/PrintStream (#24)
#18 = NameAndType println:(I)V (#25:#26)
#19 = Utf8: PrintInt
#20 = Utf8: java/lang/Object
#21 = Utf8: java/lang/System
#22 = Utf8: out
#23 = Utf8: Ljava/io/PrintStream;
#24 = Utf8: java/io/PrintStream
#25 = Utf8: println
#26 = Utf8: (I)V
Interfaces: (Count: 0) {
}
Fields: (Count: 0) {
}
Methods: (Count: 2) {
<init>
Descriptor: ()V
Flags: ACC_PUBLIC
Code: (Lenght: 29)
stack=1, locals=1
0 aload_0 (0x2a)
1 invokespecial #1 java/lang/Object.<init>:()V (0xb7)
4 return (0xb1)
LineNumberTable: (Lenght: 6)
line 1: 0
main
Descriptor: ([Ljava/lang/String;)V
Flags: ACC_PUBLIC ACC_STATIC
Code: (Lenght: 49)
stack=2, locals=1
0 getstatic #2 java/lang/System.out:Ljava/io/PrintStream; (0xb2)
3 bipush 12 (0x10)
5 invokevirtual #3 java/io/PrintStream.println:(I)V (0xb6)
8 getstatic #2 java/lang/System.out:Ljava/io/PrintStream; (0xb2)
11 bipush 223 (0x10)
13 invokevirtual #3 java/io/PrintStream.println:(I)V (0xb6)
16 return (0xb1)
LineNumberTable: (Lenght: 14)
line 3: 0
line 4: 8
line 5: 16
}
SourceFile: (Lenght: 2) "PrintInt.java"