FAILURE MAP
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FA-89956 / Bytecode virtual machines / Open access

Exception tables: protected range end treated as inclusive · case 01

An exception raised by the first instruction after a try block is caught by that block's handler.

Verified by executionVariant 1 · 10 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The range test uses pc <= end although end is exclusive.

THE FAILURE

The range test uses pc <= end although end is exclusive.

Unsuccessful approach: Shifting both bounds makes the start exclusive and the end inclusive, which misses the first protected instruction.

Case contract

frames are ordered outermost first; the innermost frame carries the faulting pc, every caller carries the return address "ret" and the invoke opcode "via" (invokeinterface and invokedynamic are 5 bytes, other invokes 3), and the lookup pc is the invoke's own address. Each table entry [start, end, handler, type] covers start <= pc < end; entries are tried in table order; type None catches anything, otherwise the thrown type or any ancestor (parents map) must equal it. Return handler, number of frames unwound and the operand stack at the handler (cleared, then the exception pushed).

Why this case matters

Exception dispatch correctness depends on half-open ranges, table order, type hierarchy and pc attribution.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(frames, exc, parents):
    def is_sub(t, target):
        while t is not None:
            if t == target:
                return True
            t = parents.get(t)
        return False
    unwound = 0
    for depth, frame in enumerate(reversed(frames)):
        if depth == 0:
            pc = frame['pc']
        else:
            pc = frame['ret'] - (5 if frame['via'] in ('invokeinterface', 'invokedynamic') else 3)
        for start, end, handler, catch in frame['table']:
            if start <= pc <= end and (catch is None or is_sub(exc, catch)):
                return {'handler': handler, 'unwound': unwound, 'stack': [exc]}
        unwound += 1
    return {'handler': None, 'unwound': unwound, 'stack': []}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = [[('range end is exclusive',
   ([{'pc': 20, 'stack': [1, 2], 'table': [[10, 20, 100, 'IOException'], [20, 30, 200, 'IOException']]}],
    'IOException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 200, 'stack': ['IOException'], 'unwound': 0}),
  ('range start is inclusive',
   ([{'pc': 10, 'stack': [1, 2], 'table': [[10, 15, 300, 'Exception']]}],
    'ArithmeticException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 300, 'stack': ['ArithmeticException'], 'unwound': 0}),
  ('regression: first matching entry in table order wins',
   ([{'pc': 17, 'stack': [1, 2], 'table': [[10, 30, 100, 'Exception'], [15, 20, 200, 'IOException']]}],
    'FileNotFoundException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 100, 'stack': ['FileNotFoundException'], 'unwound': 0}),
  ('subclass instance caught by superclass handler',
   ([{'pc': 11, 'stack': [1, 2], 'table': [[10, 19, 150, 'IOException']]}],
    'FileNotFoundException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 150, 'stack': ['FileNotFoundException'], 'unwound': 0}),
  ('superclass instance not caught by subclass handler',
   ([{'pc': 11, 'stack': [1, 2], 'table': [[10, 19, 150, 'FileNotFoundException']]}],
    'IOException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': None, 'stack': [], 'unwound': 1}),
  ('any-type entry catches errors',
   ([{'pc': 12, 'stack': [1, 2], 'table': [[10, 19, 400, None]]}],
    'StackOverflowError',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 400, 'stack': ['StackOverflowError'], 'unwound': 0}),
  ('Exception handler does not catch Error',
   ([{'pc': 12, 'stack': [1, 2], 'table': [[10, 19, 410, 'Exception']]}],
    'AssertionError',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': None, 'stack': [], 'unwound': 1}),
  ('caller frame after 3-byte invoke',
   ([{'ret': 23, 'stack': [1], 'table': [[20, 23, 500, 'Exception']], 'via': 'invokestatic'},
     {'pc': 3, 'stack': [1, 2], 'table': []}],
    'RuntimeException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 500, 'stack': ['RuntimeException'], 'unwound': 1}),
  ('caller frame after 5-byte invokeinterface',
   ([{'ret': 25, 'stack': [1], 'table': [[20, 25, 600, None]], 'via': 'invokeinterface'},
     {'pc': 3, 'stack': [1, 2], 'table': []}],
    'IOException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 600, 'stack': ['IOException'], 'unwound': 1}),
  ('control: uncaught through two frames',
   ([{'ret': 13, 'stack': [], 'table': [[15, 19, 1, None]], 'via': 'invokevirtual'},
     {'pc': 4, 'stack': [1, 2], 'table': [[0, 3, 2, None]]}],
    'Error',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': None, 'stack': [], 'unwound': 2})],
 [('range end is exclusive',
   ([{'pc': 30, 'stack': [2, 2], 'table': [[20, 30, 100, 'IOException'], [30, 40, 200, 'IOException']]}],
    'IOException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 200, 'stack': ['IOException'], 'unwound': 0}),
  ('range start is inclusive',
   ([{'pc': 20, 'stack': [2, 2], 'table': [[20, 25, 300, 'Exception']]}],
    'ArithmeticException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 300, 'stack': ['ArithmeticException'], 'unwound': 0}),
  ('regression: first matching entry in table order wins',
   ([{'pc': 27, 'stack': [2, 2], 'table': [[20, 40, 100, 'Exception'], [25, 30, 200, 'IOException']]}],
    'FileNotFoundException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 100, 'stack': ['FileNotFoundException'], 'unwound': 0}),
  ('subclass instance caught by superclass handler',
   ([{'pc': 21, 'stack': [2, 2], 'table': [[20, 29, 150, 'IOException']]}],
    'FileNotFoundException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 150, 'stack': ['FileNotFoundException'], 'unwound': 0}),
  ('superclass instance not caught by subclass handler',
   ([{'pc': 21, 'stack': [2, 2], 'table': [[20, 29, 150, 'FileNotFoundException']]}],
    'IOException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': None, 'stack': [], 'unwound': 1}),
  ('any-type entry catches errors',
   ([{'pc': 22, 'stack': [2, 2], 'table': [[20, 29, 400, None]]}],
    'StackOverflowError',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 400, 'stack': ['StackOverflowError'], 'unwound': 0}),
  ('Exception handler does not catch Error',
   ([{'pc': 22, 'stack': [2, 2], 'table': [[20, 29, 410, 'Exception']]}],
    'AssertionError',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': None, 'stack': [], 'unwound': 1}),
  ('caller frame after 3-byte invoke',
   ([{'ret': 33, 'stack': [1], 'table': [[30, 33, 500, 'Exception']], 'via': 'invokestatic'},
     {'pc': 3, 'stack': [2, 2], 'table': []}],
    'RuntimeException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 500, 'stack': ['RuntimeException'], 'unwound': 1}),
  ('caller frame after 5-byte invokeinterface',
   ([{'ret': 35, 'stack': [1], 'table': [[30, 35, 600, None]], 'via': 'invokeinterface'},
     {'pc': 3, 'stack': [2, 2], 'table': []}],
    'IOException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 600, 'stack': ['IOException'], 'unwound': 1}),
  ('control: uncaught through two frames',
   ([{'ret': 23, 'stack': [], 'table': [[25, 29, 1, None]], 'via': 'invokevirtual'},
     {'pc': 4, 'stack': [2, 2], 'table': [[0, 3, 2, None]]}],
    'Error',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': None, 'stack': [], 'unwound': 2})],
 [('range end is exclusive',
   ([{'pc': 40, 'stack': [3, 2], 'table': [[30, 40, 100, 'IOException'], [40, 50, 200, 'IOException']]}],
    'IOException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 200, 'stack': ['IOException'], 'unwound': 0}),
  ('range start is inclusive',
   ([{'pc': 30, 'stack': [3, 2], 'table': [[30, 35, 300, 'Exception']]}],
    'ArithmeticException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 300, 'stack': ['ArithmeticException'], 'unwound': 0}),
  ('regression: first matching entry in table order wins',
   ([{'pc': 37, 'stack': [3, 2], 'table': [[30, 50, 100, 'Exception'], [35, 40, 200, 'IOException']]}],
    'FileNotFoundException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 100, 'stack': ['FileNotFoundException'], 'unwound': 0}),
  ('subclass instance caught by superclass handler',
   ([{'pc': 31, 'stack': [3, 2], 'table': [[30, 39, 150, 'IOException']]}],
    'FileNotFoundException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 150, 'stack': ['FileNotFoundException'], 'unwound': 0}),
  ('superclass instance not caught by subclass handler',
   ([{'pc': 31, 'stack': [3, 2], 'table': [[30, 39, 150, 'FileNotFoundException']]}],
    'IOException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': None, 'stack': [], 'unwound': 1}),
  ('any-type entry catches errors',
   ([{'pc': 32, 'stack': [3, 2], 'table': [[30, 39, 400, None]]}],
    'StackOverflowError',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 400, 'stack': ['StackOverflowError'], 'unwound': 0}),
  ('Exception handler does not catch Error',
   ([{'pc': 32, 'stack': [3, 2], 'table': [[30, 39, 410, 'Exception']]}],
    'AssertionError',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': None, 'stack': [], 'unwound': 1}),
  ('caller frame after 3-byte invoke',
   ([{'ret': 43, 'stack': [1], 'table': [[40, 43, 500, 'Exception']], 'via': 'invokestatic'},
     {'pc': 3, 'stack': [3, 2], 'table': []}],
    'RuntimeException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 500, 'stack': ['RuntimeException'], 'unwound': 1}),
  ('caller frame after 5-byte invokeinterface',
   ([{'ret': 45, 'stack': [1], 'table': [[40, 45, 600, None]], 'via': 'invokeinterface'},
     {'pc': 3, 'stack': [3, 2], 'table': []}],
    'IOException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 600, 'stack': ['IOException'], 'unwound': 1}),
  ('control: uncaught through two frames',
   ([{'ret': 33, 'stack': [], 'table': [[35, 39, 1, None]], 'via': 'invokevirtual'},
     {'pc': 4, 'stack': [3, 2], 'table': [[0, 3, 2, None]]}],
    'Error',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': None, 'stack': [], 'unwound': 2})],
 [('range end is exclusive',
   ([{'pc': 50, 'stack': [4, 2], 'table': [[40, 50, 100, 'IOException'], [50, 60, 200, 'IOException']]}],
    'IOException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 200, 'stack': ['IOException'], 'unwound': 0}),
  ('range start is inclusive',
   ([{'pc': 40, 'stack': [4, 2], 'table': [[40, 45, 300, 'Exception']]}],
    'ArithmeticException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 300, 'stack': ['ArithmeticException'], 'unwound': 0}),
  ('regression: first matching entry in table order wins',
   ([{'pc': 47, 'stack': [4, 2], 'table': [[40, 60, 100, 'Exception'], [45, 50, 200, 'IOException']]}],
    'FileNotFoundException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 100, 'stack': ['FileNotFoundException'], 'unwound': 0}),
  ('subclass instance caught by superclass handler',
   ([{'pc': 41, 'stack': [4, 2], 'table': [[40, 49, 150, 'IOException']]}],
    'FileNotFoundException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 150, 'stack': ['FileNotFoundException'], 'unwound': 0}),
  ('superclass instance not caught by subclass handler',
   ([{'pc': 41, 'stack': [4, 2], 'table': [[40, 49, 150, 'FileNotFoundException']]}],
    'IOException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': None, 'stack': [], 'unwound': 1}),
  ('any-type entry catches errors',
   ([{'pc': 42, 'stack': [4, 2], 'table': [[40, 49, 400, None]]}],
    'StackOverflowError',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 400, 'stack': ['StackOverflowError'], 'unwound': 0}),
  ('Exception handler does not catch Error',
   ([{'pc': 42, 'stack': [4, 2], 'table': [[40, 49, 410, 'Exception']]}],
    'AssertionError',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': None, 'stack': [], 'unwound': 1}),
  ('caller frame after 3-byte invoke',
   ([{'ret': 53, 'stack': [1], 'table': [[50, 53, 500, 'Exception']], 'via': 'invokestatic'},
     {'pc': 3, 'stack': [4, 2], 'table': []}],
    'RuntimeException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 500, 'stack': ['RuntimeException'], 'unwound': 1}),
  ('caller frame after 5-byte invokeinterface',
   ([{'ret': 55, 'stack': [1], 'table': [[50, 55, 600, None]], 'via': 'invokeinterface'},
     {'pc': 3, 'stack': [4, 2], 'table': []}],
    'IOException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 600, 'stack': ['IOException'], 'unwound': 1}),
  ('control: uncaught through two frames',
   ([{'ret': 43, 'stack': [], 'table': [[45, 49, 1, None]], 'via': 'invokevirtual'},
     {'pc': 4, 'stack': [4, 2], 'table': [[0, 3, 2, None]]}],
    'Error',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': None, 'stack': [], 'unwound': 2})],
 [('range end is exclusive',
   ([{'pc': 60, 'stack': [5, 2], 'table': [[50, 60, 100, 'IOException'], [60, 70, 200, 'IOException']]}],
    'IOException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 200, 'stack': ['IOException'], 'unwound': 0}),
  ('range start is inclusive',
   ([{'pc': 50, 'stack': [5, 2], 'table': [[50, 55, 300, 'Exception']]}],
    'ArithmeticException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 300, 'stack': ['ArithmeticException'], 'unwound': 0}),
  ('regression: first matching entry in table order wins',
   ([{'pc': 57, 'stack': [5, 2], 'table': [[50, 70, 100, 'Exception'], [55, 60, 200, 'IOException']]}],
    'FileNotFoundException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 100, 'stack': ['FileNotFoundException'], 'unwound': 0}),
  ('subclass instance caught by superclass handler',
   ([{'pc': 51, 'stack': [5, 2], 'table': [[50, 59, 150, 'IOException']]}],
    'FileNotFoundException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 150, 'stack': ['FileNotFoundException'], 'unwound': 0}),
  ('superclass instance not caught by subclass handler',
   ([{'pc': 51, 'stack': [5, 2], 'table': [[50, 59, 150, 'FileNotFoundException']]}],
    'IOException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': None, 'stack': [], 'unwound': 1}),
  ('any-type entry catches errors',
   ([{'pc': 52, 'stack': [5, 2], 'table': [[50, 59, 400, None]]}],
    'StackOverflowError',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 400, 'stack': ['StackOverflowError'], 'unwound': 0}),
  ('Exception handler does not catch Error',
   ([{'pc': 52, 'stack': [5, 2], 'table': [[50, 59, 410, 'Exception']]}],
    'AssertionError',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': None, 'stack': [], 'unwound': 1}),
  ('caller frame after 3-byte invoke',
   ([{'ret': 63, 'stack': [1], 'table': [[60, 63, 500, 'Exception']], 'via': 'invokestatic'},
     {'pc': 3, 'stack': [5, 2], 'table': []}],
    'RuntimeException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 500, 'stack': ['RuntimeException'], 'unwound': 1}),
  ('caller frame after 5-byte invokeinterface',
   ([{'ret': 65, 'stack': [1], 'table': [[60, 65, 600, None]], 'via': 'invokeinterface'},
     {'pc': 3, 'stack': [5, 2], 'table': []}],
    'IOException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 600, 'stack': ['IOException'], 'unwound': 1}),
  ('control: uncaught through two frames',
   ([{'ret': 53, 'stack': [], 'table': [[55, 59, 1, None]], 'via': 'invokevirtual'},
     {'pc': 4, 'stack': [5, 2], 'table': [[0, 3, 2, None]]}],
    'Error',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': None, 'stack': [], 'unwound': 2})]]
for label, args, expected in cases[N - 1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
range end is exclusive{'handler': 100, 'stack': ['IOException'], 'unwound': 0}{'handler': 200, 'stack': ['IOException'], 'unwound': 0}Failed
range start is inclusive{'handler': 300, 'stack': ['ArithmeticException'], 'unwound': 0}{'handler': 300, 'stack': ['ArithmeticException'], 'unwound': 0}Passed
regression: first matching entry in table order wins{'handler': 100, 'stack': ['FileNotFoundException'], 'unwound': 0}{'handler': 100, 'stack': ['FileNotFoundException'], 'unwound': 0}Passed
subclass instance caught by superclass handler{'handler': 150, 'stack': ['FileNotFoundException'], 'unwound': 0}{'handler': 150, 'stack': ['FileNotFoundException'], 'unwound': 0}Passed
superclass instance not caught by subclass handler{'handler': None, 'stack': [], 'unwound': 1}{'handler': None, 'stack': [], 'unwound': 1}Passed
any-type entry catches errors{'handler': 400, 'stack': ['StackOverflowError'], 'unwound': 0}{'handler': 400, 'stack': ['StackOverflowError'], 'unwound': 0}Passed
Exception handler does not catch Error{'handler': None, 'stack': [], 'unwound': 1}{'handler': None, 'stack': [], 'unwound': 1}Passed
caller frame after 3-byte invoke{'handler': 500, 'stack': ['RuntimeException'], 'unwound': 1}{'handler': 500, 'stack': ['RuntimeException'], 'unwound': 1}Passed
caller frame after 5-byte invokeinterface{'handler': 600, 'stack': ['IOException'], 'unwound': 1}{'handler': 600, 'stack': ['IOException'], 'unwound': 1}Passed
control: uncaught through two frames{'handler': None, 'stack': [], 'unwound': 2}{'handler': None, 'stack': [], 'unwound': 2}Passed

SHA-256 / 33132d545b7c4232219523f24e8c163de38faa70101cdba6c7e94795a5013e24

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(frames, exc, parents):
    def is_sub(t, target):
        while t is not None:
            if t == target:
                return True
            t = parents.get(t)
        return False
    unwound = 0
    for depth, frame in enumerate(reversed(frames)):
        if depth == 0:
            pc = frame['pc']
        else:
            pc = frame['ret'] - (5 if frame['via'] in ('invokeinterface', 'invokedynamic') else 3)
        for start, end, handler, catch in frame['table']:
            if start < pc <= end and (catch is None or is_sub(exc, catch)):
                return {'handler': handler, 'unwound': unwound, 'stack': [exc]}
        unwound += 1
    return {'handler': None, 'unwound': unwound, 'stack': []}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = [[('range end is exclusive',
   ([{'pc': 20, 'stack': [1, 2], 'table': [[10, 20, 100, 'IOException'], [20, 30, 200, 'IOException']]}],
    'IOException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 200, 'stack': ['IOException'], 'unwound': 0}),
  ('range start is inclusive',
   ([{'pc': 10, 'stack': [1, 2], 'table': [[10, 15, 300, 'Exception']]}],
    'ArithmeticException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 300, 'stack': ['ArithmeticException'], 'unwound': 0}),
  ('regression: first matching entry in table order wins',
   ([{'pc': 17, 'stack': [1, 2], 'table': [[10, 30, 100, 'Exception'], [15, 20, 200, 'IOException']]}],
    'FileNotFoundException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 100, 'stack': ['FileNotFoundException'], 'unwound': 0}),
  ('subclass instance caught by superclass handler',
   ([{'pc': 11, 'stack': [1, 2], 'table': [[10, 19, 150, 'IOException']]}],
    'FileNotFoundException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 150, 'stack': ['FileNotFoundException'], 'unwound': 0}),
  ('superclass instance not caught by subclass handler',
   ([{'pc': 11, 'stack': [1, 2], 'table': [[10, 19, 150, 'FileNotFoundException']]}],
    'IOException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': None, 'stack': [], 'unwound': 1}),
  ('any-type entry catches errors',
   ([{'pc': 12, 'stack': [1, 2], 'table': [[10, 19, 400, None]]}],
    'StackOverflowError',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 400, 'stack': ['StackOverflowError'], 'unwound': 0}),
  ('Exception handler does not catch Error',
   ([{'pc': 12, 'stack': [1, 2], 'table': [[10, 19, 410, 'Exception']]}],
    'AssertionError',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': None, 'stack': [], 'unwound': 1}),
  ('caller frame after 3-byte invoke',
   ([{'ret': 23, 'stack': [1], 'table': [[20, 23, 500, 'Exception']], 'via': 'invokestatic'},
     {'pc': 3, 'stack': [1, 2], 'table': []}],
    'RuntimeException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 500, 'stack': ['RuntimeException'], 'unwound': 1}),
  ('caller frame after 5-byte invokeinterface',
   ([{'ret': 25, 'stack': [1], 'table': [[20, 25, 600, None]], 'via': 'invokeinterface'},
     {'pc': 3, 'stack': [1, 2], 'table': []}],
    'IOException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 600, 'stack': ['IOException'], 'unwound': 1}),
  ('control: uncaught through two frames',
   ([{'ret': 13, 'stack': [], 'table': [[15, 19, 1, None]], 'via': 'invokevirtual'},
     {'pc': 4, 'stack': [1, 2], 'table': [[0, 3, 2, None]]}],
    'Error',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': None, 'stack': [], 'unwound': 2})],
 [('range end is exclusive',
   ([{'pc': 30, 'stack': [2, 2], 'table': [[20, 30, 100, 'IOException'], [30, 40, 200, 'IOException']]}],
    'IOException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 200, 'stack': ['IOException'], 'unwound': 0}),
  ('range start is inclusive',
   ([{'pc': 20, 'stack': [2, 2], 'table': [[20, 25, 300, 'Exception']]}],
    'ArithmeticException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 300, 'stack': ['ArithmeticException'], 'unwound': 0}),
  ('regression: first matching entry in table order wins',
   ([{'pc': 27, 'stack': [2, 2], 'table': [[20, 40, 100, 'Exception'], [25, 30, 200, 'IOException']]}],
    'FileNotFoundException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 100, 'stack': ['FileNotFoundException'], 'unwound': 0}),
  ('subclass instance caught by superclass handler',
   ([{'pc': 21, 'stack': [2, 2], 'table': [[20, 29, 150, 'IOException']]}],
    'FileNotFoundException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 150, 'stack': ['FileNotFoundException'], 'unwound': 0}),
  ('superclass instance not caught by subclass handler',
   ([{'pc': 21, 'stack': [2, 2], 'table': [[20, 29, 150, 'FileNotFoundException']]}],
    'IOException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': None, 'stack': [], 'unwound': 1}),
  ('any-type entry catches errors',
   ([{'pc': 22, 'stack': [2, 2], 'table': [[20, 29, 400, None]]}],
    'StackOverflowError',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 400, 'stack': ['StackOverflowError'], 'unwound': 0}),
  ('Exception handler does not catch Error',
   ([{'pc': 22, 'stack': [2, 2], 'table': [[20, 29, 410, 'Exception']]}],
    'AssertionError',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': None, 'stack': [], 'unwound': 1}),
  ('caller frame after 3-byte invoke',
   ([{'ret': 33, 'stack': [1], 'table': [[30, 33, 500, 'Exception']], 'via': 'invokestatic'},
     {'pc': 3, 'stack': [2, 2], 'table': []}],
    'RuntimeException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 500, 'stack': ['RuntimeException'], 'unwound': 1}),
  ('caller frame after 5-byte invokeinterface',
   ([{'ret': 35, 'stack': [1], 'table': [[30, 35, 600, None]], 'via': 'invokeinterface'},
     {'pc': 3, 'stack': [2, 2], 'table': []}],
    'IOException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 600, 'stack': ['IOException'], 'unwound': 1}),
  ('control: uncaught through two frames',
   ([{'ret': 23, 'stack': [], 'table': [[25, 29, 1, None]], 'via': 'invokevirtual'},
     {'pc': 4, 'stack': [2, 2], 'table': [[0, 3, 2, None]]}],
    'Error',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': None, 'stack': [], 'unwound': 2})],
 [('range end is exclusive',
   ([{'pc': 40, 'stack': [3, 2], 'table': [[30, 40, 100, 'IOException'], [40, 50, 200, 'IOException']]}],
    'IOException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 200, 'stack': ['IOException'], 'unwound': 0}),
  ('range start is inclusive',
   ([{'pc': 30, 'stack': [3, 2], 'table': [[30, 35, 300, 'Exception']]}],
    'ArithmeticException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 300, 'stack': ['ArithmeticException'], 'unwound': 0}),
  ('regression: first matching entry in table order wins',
   ([{'pc': 37, 'stack': [3, 2], 'table': [[30, 50, 100, 'Exception'], [35, 40, 200, 'IOException']]}],
    'FileNotFoundException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 100, 'stack': ['FileNotFoundException'], 'unwound': 0}),
  ('subclass instance caught by superclass handler',
   ([{'pc': 31, 'stack': [3, 2], 'table': [[30, 39, 150, 'IOException']]}],
    'FileNotFoundException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 150, 'stack': ['FileNotFoundException'], 'unwound': 0}),
  ('superclass instance not caught by subclass handler',
   ([{'pc': 31, 'stack': [3, 2], 'table': [[30, 39, 150, 'FileNotFoundException']]}],
    'IOException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': None, 'stack': [], 'unwound': 1}),
  ('any-type entry catches errors',
   ([{'pc': 32, 'stack': [3, 2], 'table': [[30, 39, 400, None]]}],
    'StackOverflowError',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 400, 'stack': ['StackOverflowError'], 'unwound': 0}),
  ('Exception handler does not catch Error',
   ([{'pc': 32, 'stack': [3, 2], 'table': [[30, 39, 410, 'Exception']]}],
    'AssertionError',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': None, 'stack': [], 'unwound': 1}),
  ('caller frame after 3-byte invoke',
   ([{'ret': 43, 'stack': [1], 'table': [[40, 43, 500, 'Exception']], 'via': 'invokestatic'},
     {'pc': 3, 'stack': [3, 2], 'table': []}],
    'RuntimeException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 500, 'stack': ['RuntimeException'], 'unwound': 1}),
  ('caller frame after 5-byte invokeinterface',
   ([{'ret': 45, 'stack': [1], 'table': [[40, 45, 600, None]], 'via': 'invokeinterface'},
     {'pc': 3, 'stack': [3, 2], 'table': []}],
    'IOException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 600, 'stack': ['IOException'], 'unwound': 1}),
  ('control: uncaught through two frames',
   ([{'ret': 33, 'stack': [], 'table': [[35, 39, 1, None]], 'via': 'invokevirtual'},
     {'pc': 4, 'stack': [3, 2], 'table': [[0, 3, 2, None]]}],
    'Error',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': None, 'stack': [], 'unwound': 2})],
 [('range end is exclusive',
   ([{'pc': 50, 'stack': [4, 2], 'table': [[40, 50, 100, 'IOException'], [50, 60, 200, 'IOException']]}],
    'IOException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 200, 'stack': ['IOException'], 'unwound': 0}),
  ('range start is inclusive',
   ([{'pc': 40, 'stack': [4, 2], 'table': [[40, 45, 300, 'Exception']]}],
    'ArithmeticException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 300, 'stack': ['ArithmeticException'], 'unwound': 0}),
  ('regression: first matching entry in table order wins',
   ([{'pc': 47, 'stack': [4, 2], 'table': [[40, 60, 100, 'Exception'], [45, 50, 200, 'IOException']]}],
    'FileNotFoundException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 100, 'stack': ['FileNotFoundException'], 'unwound': 0}),
  ('subclass instance caught by superclass handler',
   ([{'pc': 41, 'stack': [4, 2], 'table': [[40, 49, 150, 'IOException']]}],
    'FileNotFoundException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 150, 'stack': ['FileNotFoundException'], 'unwound': 0}),
  ('superclass instance not caught by subclass handler',
   ([{'pc': 41, 'stack': [4, 2], 'table': [[40, 49, 150, 'FileNotFoundException']]}],
    'IOException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': None, 'stack': [], 'unwound': 1}),
  ('any-type entry catches errors',
   ([{'pc': 42, 'stack': [4, 2], 'table': [[40, 49, 400, None]]}],
    'StackOverflowError',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 400, 'stack': ['StackOverflowError'], 'unwound': 0}),
  ('Exception handler does not catch Error',
   ([{'pc': 42, 'stack': [4, 2], 'table': [[40, 49, 410, 'Exception']]}],
    'AssertionError',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': None, 'stack': [], 'unwound': 1}),
  ('caller frame after 3-byte invoke',
   ([{'ret': 53, 'stack': [1], 'table': [[50, 53, 500, 'Exception']], 'via': 'invokestatic'},
     {'pc': 3, 'stack': [4, 2], 'table': []}],
    'RuntimeException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 500, 'stack': ['RuntimeException'], 'unwound': 1}),
  ('caller frame after 5-byte invokeinterface',
   ([{'ret': 55, 'stack': [1], 'table': [[50, 55, 600, None]], 'via': 'invokeinterface'},
     {'pc': 3, 'stack': [4, 2], 'table': []}],
    'IOException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 600, 'stack': ['IOException'], 'unwound': 1}),
  ('control: uncaught through two frames',
   ([{'ret': 43, 'stack': [], 'table': [[45, 49, 1, None]], 'via': 'invokevirtual'},
     {'pc': 4, 'stack': [4, 2], 'table': [[0, 3, 2, None]]}],
    'Error',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': None, 'stack': [], 'unwound': 2})],
 [('range end is exclusive',
   ([{'pc': 60, 'stack': [5, 2], 'table': [[50, 60, 100, 'IOException'], [60, 70, 200, 'IOException']]}],
    'IOException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 200, 'stack': ['IOException'], 'unwound': 0}),
  ('range start is inclusive',
   ([{'pc': 50, 'stack': [5, 2], 'table': [[50, 55, 300, 'Exception']]}],
    'ArithmeticException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 300, 'stack': ['ArithmeticException'], 'unwound': 0}),
  ('regression: first matching entry in table order wins',
   ([{'pc': 57, 'stack': [5, 2], 'table': [[50, 70, 100, 'Exception'], [55, 60, 200, 'IOException']]}],
    'FileNotFoundException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 100, 'stack': ['FileNotFoundException'], 'unwound': 0}),
  ('subclass instance caught by superclass handler',
   ([{'pc': 51, 'stack': [5, 2], 'table': [[50, 59, 150, 'IOException']]}],
    'FileNotFoundException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 150, 'stack': ['FileNotFoundException'], 'unwound': 0}),
  ('superclass instance not caught by subclass handler',
   ([{'pc': 51, 'stack': [5, 2], 'table': [[50, 59, 150, 'FileNotFoundException']]}],
    'IOException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': None, 'stack': [], 'unwound': 1}),
  ('any-type entry catches errors',
   ([{'pc': 52, 'stack': [5, 2], 'table': [[50, 59, 400, None]]}],
    'StackOverflowError',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 400, 'stack': ['StackOverflowError'], 'unwound': 0}),
  ('Exception handler does not catch Error',
   ([{'pc': 52, 'stack': [5, 2], 'table': [[50, 59, 410, 'Exception']]}],
    'AssertionError',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': None, 'stack': [], 'unwound': 1}),
  ('caller frame after 3-byte invoke',
   ([{'ret': 63, 'stack': [1], 'table': [[60, 63, 500, 'Exception']], 'via': 'invokestatic'},
     {'pc': 3, 'stack': [5, 2], 'table': []}],
    'RuntimeException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 500, 'stack': ['RuntimeException'], 'unwound': 1}),
  ('caller frame after 5-byte invokeinterface',
   ([{'ret': 65, 'stack': [1], 'table': [[60, 65, 600, None]], 'via': 'invokeinterface'},
     {'pc': 3, 'stack': [5, 2], 'table': []}],
    'IOException',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': 600, 'stack': ['IOException'], 'unwound': 1}),
  ('control: uncaught through two frames',
   ([{'ret': 53, 'stack': [], 'table': [[55, 59, 1, None]], 'via': 'invokevirtual'},
     {'pc': 4, 'stack': [5, 2], 'table': [[0, 3, 2, None]]}],
    'Error',
    {'ArithmeticException': 'RuntimeException',
     'AssertionError': 'Error',
     'Error': 'Throwable',
     'Exception': 'Throwable',
     'FileNotFoundException': 'IOException',
     'IOException': 'Exception',
     'RuntimeException': 'Exception',
     'StackOverflowError': 'VirtualMachineError',
     'VirtualMachineError': 'Error'}),
   {'handler': None, 'stack': [], 'unwound': 2})]]
for label, args, expected in cases[N - 1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
range end is exclusive{'handler': 100, 'stack': ['IOException'], 'unwound': 0}{'handler': 200, 'stack': ['IOException'], 'unwound': 0}Failed
range start is inclusive{'handler': None, 'stack': [], 'unwound': 1}{'handler': 300, 'stack': ['ArithmeticException'], 'unwound': 0}Failed
regression: first matching entry in table order wins{'handler': 100, 'stack': ['FileNotFoundException'], 'unwound': 0}{'handler': 100, 'stack': ['FileNotFoundException'], 'unwound': 0}Passed
subclass instance caught by superclass handler{'handler': 150, 'stack': ['FileNotFoundException'], 'unwound': 0}{'handler': 150, 'stack': ['FileNotFoundException'], 'unwound': 0}Passed
superclass instance not caught by subclass handler{'handler': None, 'stack': [], 'unwound': 1}{'handler': None, 'stack': [], 'unwound': 1}Passed
any-type entry catches errors{'handler': 400, 'stack': ['StackOverflowError'], 'unwound': 0}{'handler': 400, 'stack': ['StackOverflowError'], 'unwound': 0}Passed
Exception handler does not catch Error{'handler': None, 'stack': [], 'unwound': 1}{'handler': None, 'stack': [], 'unwound': 1}Passed
caller frame after 3-byte invoke{'handler': None, 'stack': [], 'unwound': 2}{'handler': 500, 'stack': ['RuntimeException'], 'unwound': 1}Failed
caller frame after 5-byte invokeinterface{'handler': None, 'stack': [], 'unwound': 2}{'handler': 600, 'stack': ['IOException'], 'unwound': 1}Failed
control: uncaught through two frames{'handler': None, 'stack': [], 'unwound': 2}{'handler': None, 'stack': [], 'unwound': 2}Passed

SHA-256 / d9984e6134fdcade3c58fed0fa3f90eee52b9d2bfc2c36d9719f256329d29034

HELD IN THE MEMBER ARCHIVE

The verified repair and its recorded checks are member-only.

This mechanism has 10 recorded checks per implementation. The open-access tier publishes the failure and the unsuccessful fix; the repaired source that passes every check, and the observations that prove it, are available to members.

Every case sharing this mechanism uses the same contract and the same repair, so this one record is held back for all of them.

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Verification & scope

A deterministic, bounded teaching model of one bytecode virtual machine mechanism with a stipulated instruction encoding; it is not a production VM and claims no conformance to any real specification. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.

Observations recorded using Python 3.12.14 at 2026-09-29T14:51:22.473655+00:00.

Case digest / 8163e5bf3ed092f4c1686cf13ce6a176d41b018ec1765fdd7461241f1901069b