嵌套Numba调用中关键字参数超3个时触发Dispatch错误排查

环境信息 #

• Numba版本：0.56.4
• Python版本：3.9.17

测试用例对比 #

通过测试用例1 #

import numba as nb
def test_1(a, b, c, d, e, f, g):
    return a + b + c + d + e + f + g
test_1 = nb.njit(test_1)

def test_2(a, b, c, d, e, f, g):
    return test_1(a, b, c, d, e, f, g)
test_2 = nb.njit(test_2)
test_2(1, 2, 3, 4, 5, 6, 7)

通过测试用例2 #

import numba as nb
def test_1(a, b, c, *, d, e, f):
    return a + b + c + d + e + f
test_1 = nb.njit(test_1)

def test_2(a, b, c, d, e, f, g):
    return test_1(a, b, c, d, e, f)
test_2 = nb.njit(test_2)
test_2(1, 2, 3, 4, 5, 6, 7)

失败测试用例3 #

import numba as nb
def test_1(a, b, c, *, d, e, f, g):
    return a + b + c + d + e + f
test_1 = nb.njit(test_1)

def test_2(a, b, c, d, e, f, g):
    return test_1(a, b, c, d, e, f, g)
test_2 = nb.njit(test_2)
test_2(1, 2, 3, 4, 5, 6, 7)

错误回溯 #

---------------------------------------------------------------------------
TypingError                               Traceback (most recent call last)
Cell In[10], line 9
      7 test_2 = nb.njit(test_2)
      8 # test_1(1, 2, 3, 4, 5, 6, 7)
----> 9 test_2(1, 2, 3, 4, 5, 6, 7)

File ~/.cache/pypoetry/virtualenvs/indices-ldm-post-process-danSbNDA-py3.9/lib/python3.9/site-packages/numba/core/dispatcher.py:467, in _DispatcherBase._compile_for_args(self, *args, **kws)
    464         msg = (f"{str(e).rstrip()} \n\nThis error may have been caused "
    465                f"by the following argument(s):\n{args_str}\n")
    466         e.patch_message(msg)
--> 467     error_rewrite(e, 'typing')
    468 except errors.UnsupportedError as e:
    469     # Something unsupported is present in the user code, add help info
    470     error_rewrite(e, 'unsupported_error')

File ~/.cache/pypoetry/virtualenvs/indices-ldm-post-process-danSbNDA-py3.9/lib/python3.9/site-packages/numba/core/dispatcher.py:409, in _DispatcherBase._compile_for_args..error_rewrite(e, issue_type)
    407     raise e
    408 else:
--> 409     raise e.with_traceback(None)

TypingError: Failed in nopython mode pipeline (step: nopython frontend)
Internal error at .
tuple index out of range
During: resolving callee type: type(CPUDispatcher())
During: typing of call at /tmp/ipykernel_3435313/3644502072.py (6)

Enable logging at debug level for details.

错误原因分析 #

对比三个测试用例的核心差异：

1. 测试用例1中test_1无强制关键字参数，参数传递逻辑符合常规，Numba编译执行正常。
2. 测试用例2中test_1通过*定义了3个强制关键字参数（d,e,f），test_2以位置参数形式传递这3个参数时，Numba能正常解析参数匹配规则。
3. 测试用例3仅将test_1的强制关键字参数数量增加到4个（d,e,f,g），test_2调用时传递3个位置参数+4个位置参数，触发Numba内部的tuple index out of range索引越界错误。

这是Numba 0.56.4版本的内部bug：在处理带有*分隔的强制关键字参数时，当强制关键字参数数量超过3个，Numba在解析参数匹配逻辑时出现索引越界问题。该问题已在Numba官方仓库提交相关记录。

内容的提问来源于stack exchange，提问作者eroot163pi