example of verifying class files with the Maxine verifier

command_prompt

D:\code\hg\maxine>mx --cp-pfx . verify "^Foo^"
WARNING: Could not create platform from native properties - using default platform
 instead: linux-amd64, isa=AMD64, 64-bit, little endian, 64-byte aligned cache, page size=8192
Initializing verifier system...
Initialized verifier system
Finding specified methods...
Found 2 methods
Verifying Foo.<init>() via type-checking
Verifying Foo.bar(int) via type-checking

D:\code\hg\maxine>mx --cp-pfx . verify -verbose "^Foo^"
WARNING: Could not create platform from native properties - using default platform
 instead: linux-amd64, isa=AMD64, 64-bit, little endian, 64-byte aligned cache, page size=8192
Initializing verifier system...
Initialized verifier system
Finding specified methods...
Found 2 methods
[Verifying Foo.<init>() via type-checking]
Input bytecode:
Stack=1, Locals=1
[1]    0: aload_0 | 42
[1]    1: invokespecial java.lang.Object.<init>():void | 183 0 1
[1]    4: return | 177
LineNumberTable:
  line 1: 0
LocalVariableTable:
  Start Length Slot Name               Descriptor            Generic-signature
  0     5      0    this               LFoo;

StackMapTable frames:
0: local[0] = uninitializedThis

Interpreting bytecode:
    local[0] = uninitializedThis
0: aload_0

    stack[0] = uninitializedThis
    local[0] = uninitializedThis
1: invokespecial

    local[0] = Foo
4: return

[Verifying Foo.bar(int) via type-checking]
Input bytecode:
Stack=1, Locals=3
[3]    0: iconst_0 | 3
[3]    1: istore_2 | 61
[4]    2: iload_1 | 27
[4]    3: tableswitch default:50 low:0 high:3 0:32 1:37 2:39 3:44 | 170 0 0 0 47 0 0 0 0 0 0 0 3 0 0 0 29 0 0 0 34 0 0 0 36 0 0 0 41
[5]    32: iconst_0 | 3
[5]    33: istore_2 | 61
[5]    34: goto 52 | 167 0 18
[6]    37: iconst_2 | 5
[6]    38: istore_2 | 61
[7]    39: iconst_4 | 7
[7]    40: istore_2 | 61
[7]    41: goto 52 | 167 0 11
[8]    44: bipush 8 | 16 8
[8]    46: istore_2 | 61
[8]    47: goto 52 | 167 0 5
[9]    50: iconst_m1 | 2
[9]    51: istore_2 | 61
[11]   52: return | 177
StackMapTable: number of entries = 6
  32: frame_type = 252 /* append_frame */
    offset_delta = 32
    locals = [ int ]
  37: frame_type = 4 /* same_frame */
    offset_delta = 4 /* implicit */
  39: frame_type = 1 /* same_frame */
    offset_delta = 1 /* implicit */
  44: frame_type = 4 /* same_frame */
    offset_delta = 4 /* implicit */
  50: frame_type = 5 /* same_frame */
    offset_delta = 5 /* implicit */
  52: frame_type = 1 /* same_frame */
    offset_delta = 1 /* implicit */
LineNumberTable:
  line 3: 0
  line 4: 2
  line 5: 32
  line 6: 37
  line 7: 39
  line 8: 44
  line 9: 50
  line 11: 52
LocalVariableTable:
  Start Length Slot Name               Descriptor            Generic-signature
  0     53     0    this               LFoo;
  0     53     1    i                  I
  2     51     2    j                  I

StackMapTable frames:
0: local[0] = Foo
     [1] = int
32: local[0] = Foo
     [1] = int
     [2] = int
37: local[0] = Foo
     [1] = int
     [2] = int
39: local[0] = Foo
     [1] = int
     [2] = int
44: local[0] = Foo
     [1] = int
     [2] = int
50: local[0] = Foo
     [1] = int
     [2] = int
52: local[0] = Foo
     [1] = int
     [2] = int

Interpreting bytecode:
    local[0] = Foo
         [1] = int
0: iconst_0

    stack[0] = int
    local[0] = Foo
         [1] = int
1: istore_2

    local[0] = Foo
         [1] = int
         [2] = int
2: iload_1

    stack[0] = int
    local[0] = Foo
         [1] = int
         [2] = int
3: tableswitch

    local[0] = Foo
         [1] = int
         [2] = int
32: iconst_0

    stack[0] = int
    local[0] = Foo
         [1] = int
         [2] = int
33: istore_2

    local[0] = Foo
         [1] = int
         [2] = int
34: goto

    local[0] = Foo
         [1] = int
         [2] = int
37: iconst_2

    stack[0] = int
    local[0] = Foo
         [1] = int
         [2] = int
38: istore_2

    local[0] = Foo
         [1] = int
         [2] = int
39: iconst_4

    stack[0] = int
    local[0] = Foo
         [1] = int
         [2] = int
40: istore_2

    local[0] = Foo
         [1] = int
         [2] = int
41: goto

    local[0] = Foo
         [1] = int
         [2] = int
44: bipush

    stack[0] = int
    local[0] = Foo
         [1] = int
         [2] = int
46: istore_2

    local[0] = Foo
         [1] = int
         [2] = int
47: goto

    local[0] = Foo
         [1] = int
         [2] = int
50: iconst_m1

    stack[0] = int
    local[0] = Foo
         [1] = int
         [2] = int
51: istore_2

    local[0] = Foo
         [1] = int
         [2] = int
52: return


D:\code\hg\maxine>

Foo.java

public class Foo {
  public void bar(int i) {
    int j = 0;
    switch (i) {
    case 0: j = 0; break;
    case 1: j = 2;
    case 2: j = 4; break;
    case 3: j = 8; break;
    default: j = -1; break;
    }
  }
}