Btukfyl

I am trying to compile a recursive function ahead of time. As a MCVE, let's take the following function:

#import numba as nb

from numba.pycc import CC

cc = CC('precompiled')



#@nb.njit

@cc.export('gsum', 'int64(int64)')

def gsum(n):

    if n>1:

        return n+gsum(n-1)

    else:

        return 1



if __name__== '__main__':

##    print(gsum(5))

    cc.compile()

If I run this code, I get the following error trace:

Traceback (most recent call last):

  File "numba_ahead.py", line 17, in <module>

    cc.compile()

  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/numba/compiler_lock.py", line 32, in _acquire_compile_lock

    return func(*args, **kwargs)

  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/numba/pycc/cc.py", line 212, in compile

    objects, dll_exports = self._compile_object_files(build_dir)

  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/numba/compiler_lock.py", line 32, in _acquire_compile_lock

    return func(*args, **kwargs)

  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/numba/pycc/cc.py", line 200, in _compile_object_files

    compiler.write_native_object(temp_obj, wrap=True)

  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/numba/pycc/compiler.py", line 198, in write_native_object

    library = self._cull_exports()

  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/numba/compiler_lock.py", line 32, in _acquire_compile_lock

    return func(*args, **kwargs)

  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/numba/pycc/compiler.py", line 157, in _cull_exports

    locals={}, library=library)

  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/numba/compiler.py", line 904, in compile_extra

    return pipeline.compile_extra(func)

  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/numba/compiler.py", line 367, in compile_extra

    return self._compile_bytecode()

  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/numba/compiler.py", line 835, in _compile_bytecode

    return self._compile_core()

  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/numba/compiler.py", line 822, in _compile_core

    res = pm.run(self.status)

  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/numba/compiler_lock.py", line 32, in _acquire_compile_lock

    return func(*args, **kwargs)

  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/numba/compiler.py", line 253, in run

    raise patched_exception

  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/numba/compiler.py", line 244, in run

    stage()

  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/numba/compiler.py", line 477, in stage_nopython_frontend

    self.locals)

  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/numba/compiler.py", line 1005, in type_inference_stage

    infer.build_constraint()

  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/numba/typeinfer.py", line 816, in build_constraint

    self.constrain_statement(inst)

  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/numba/typeinfer.py", line 1016, in constrain_statement

    self.typeof_assign(inst)

  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/numba/typeinfer.py", line 1079, in typeof_assign

    self.typeof_global(inst, inst.target, value)

  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/numba/typeinfer.py", line 1177, in typeof_global

    typ = self.resolve_value_type(inst, gvar.value)

  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/numba/typeinfer.py", line 1100, in resolve_value_type

    raise TypingError(msg, loc=inst.loc)

numba.errors.TypingError: Failed in nopython mode pipeline (step: nopython frontend)

Untyped global name 'gsum': cannot determine Numba type of <class 'function'>



File "numba_ahead.py", line 9:

def gsum(n):

    <source elided>

    if n>1:

        return n+gsum(n-1)

        ^

So apparently cc.export doesn't know the type of the function it is compiling, if that function calls itself. Is there any way to fix the problem? When I compile the same code just in time with njit (commented-out lines) the code compiles just fine.