Overflow error in doctests

I am trying to build Cython 0.27 and 0.27.1 for openSUSE and I am getting an OverFlow error in the docstests when I run python3 runtests.py -vv (but not for python2) under an x86_64 architecture. This works fine up to Cython 0.26.1, but fails for 0.27 and 0.27.1 in the same way. We are using python 3.6.2 and 2.7.13 and gcc 7.2.1.

======================================================================
FAIL: int_abs (builtin_abs)
Doctest: builtin_abs.int_abs
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/lib64/python3.6/doctest.py", line 2199, in runTest
    raise self.failureException(self.format_failure(new.getvalue()))
AssertionError: Failed doctest test for builtin_abs.int_abs
  File "/home/abuild/rpmbuild/BUILD/Cython-0.27.1/TEST_TMP/run/c/builtin_abs/builtin_abs.cpython-36m-x86_64-linux-gnu.so", line unknown line number, in int_abs

----------------------------------------------------------------------
File "/home/abuild/rpmbuild/BUILD/Cython-0.27.1/TEST_TMP/run/c/builtin_abs/builtin_abs.cpython-36m-x86_64-linux-gnu.so", line ?, in builtin_abs.int_abs
Failed example:
    int_abs(-max_int-1)     #doctest: +ELLIPSIS
Expected:
    Traceback (most recent call last):
        ...
    OverflowError: ...
Got:
    -2147483648


======================================================================
FAIL: long_abs (builtin_abs)
Doctest: builtin_abs.long_abs
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/lib64/python3.6/doctest.py", line 2199, in runTest
    raise self.failureException(self.format_failure(new.getvalue()))
AssertionError: Failed doctest test for builtin_abs.long_abs
  File "/home/abuild/rpmbuild/BUILD/Cython-0.27.1/TEST_TMP/run/c/builtin_abs/builtin_abs.cpython-36m-x86_64-linux-gnu.so", line unknown line number, in long_abs

----------------------------------------------------------------------
File "/home/abuild/rpmbuild/BUILD/Cython-0.27.1/TEST_TMP/run/c/builtin_abs/builtin_abs.cpython-36m-x86_64-linux-gnu.so", line ?, in builtin_abs.long_abs
Failed example:
    long_abs(-max_long-1)     #doctest: +ELLIPSIS
Expected:
    Traceback (most recent call last):
        ...
    OverflowError: ...
Got:
    -9223372036854775808


======================================================================
FAIL: long_long_abs (builtin_abs)
Doctest: builtin_abs.long_long_abs
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/lib64/python3.6/doctest.py", line 2199, in runTest
    raise self.failureException(self.format_failure(new.getvalue()))
AssertionError: Failed doctest test for builtin_abs.long_long_abs
  File "/home/abuild/rpmbuild/BUILD/Cython-0.27.1/TEST_TMP/run/c/builtin_abs/builtin_abs.cpython-36m-x86_64-linux-gnu.so", line unknown line number, in long_long_abs

----------------------------------------------------------------------
File "/home/abuild/rpmbuild/BUILD/Cython-0.27.1/TEST_TMP/run/c/builtin_abs/builtin_abs.cpython-36m-x86_64-linux-gnu.so", line ?, in builtin_abs.long_long_abs
Failed example:
    long_long_abs(-max_long_long-1)     #doctest: +ELLIPSIS
Expected:
    Traceback (most recent call last):
        ...
    OverflowError: ...
Got:
    -9223372036854775808


======================================================================
FAIL: int_abs (builtin_abs)
Doctest: builtin_abs.int_abs
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/lib64/python3.6/doctest.py", line 2199, in runTest
    raise self.failureException(self.format_failure(new.getvalue()))
AssertionError: Failed doctest test for builtin_abs.int_abs
  File "/home/abuild/rpmbuild/BUILD/Cython-0.27.1/TEST_TMP/run/cpp/builtin_abs/builtin_abs.cpython-36m-x86_64-linux-gnu.so", line unknown line number, in int_abs

----------------------------------------------------------------------
File "/home/abuild/rpmbuild/BUILD/Cython-0.27.1/TEST_TMP/run/cpp/builtin_abs/builtin_abs.cpython-36m-x86_64-linux-gnu.so", line ?, in builtin_abs.int_abs
Failed example:
    int_abs(-max_int-1)     #doctest: +ELLIPSIS
Expected:
    Traceback (most recent call last):
        ...
    OverflowError: ...
Got:
    -2147483648


======================================================================
FAIL: long_abs (builtin_abs)
Doctest: builtin_abs.long_abs
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/lib64/python3.6/doctest.py", line 2199, in runTest
    raise self.failureException(self.format_failure(new.getvalue()))
AssertionError: Failed doctest test for builtin_abs.long_abs
  File "/home/abuild/rpmbuild/BUILD/Cython-0.27.1/TEST_TMP/run/cpp/builtin_abs/builtin_abs.cpython-36m-x86_64-linux-gnu.so", line unknown line number, in long_abs

----------------------------------------------------------------------
File "/home/abuild/rpmbuild/BUILD/Cython-0.27.1/TEST_TMP/run/cpp/builtin_abs/builtin_abs.cpython-36m-x86_64-linux-gnu.so", line ?, in builtin_abs.long_abs
Failed example:
    long_abs(-max_long-1)     #doctest: +ELLIPSIS
Expected:
    Traceback (most recent call last):
        ...
    OverflowError: ...
Got:
    -9223372036854775808


======================================================================
FAIL: long_long_abs (builtin_abs)
Doctest: builtin_abs.long_long_abs
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/lib64/python3.6/doctest.py", line 2199, in runTest
    raise self.failureException(self.format_failure(new.getvalue()))
AssertionError: Failed doctest test for builtin_abs.long_long_abs
  File "/home/abuild/rpmbuild/BUILD/Cython-0.27.1/TEST_TMP/run/cpp/builtin_abs/builtin_abs.cpython-36m-x86_64-linux-gnu.so", line unknown line number, in long_long_abs

----------------------------------------------------------------------
File "/home/abuild/rpmbuild/BUILD/Cython-0.27.1/TEST_TMP/run/cpp/builtin_abs/builtin_abs.cpython-36m-x86_64-linux-gnu.so", line ?, in builtin_abs.long_long_abs
Failed example:
    long_long_abs(-max_long_long-1)     #doctest: +ELLIPSIS
Expected:
    Traceback (most recent call last):
        ...
    OverflowError: ...
Got:
    -9223372036854775808

[kiwifb]

Also reported in Gentoo https://bugs.gentoo.org/632519 - I can reproduce it with gcc-6.4.0. I am guessing that is because gcc now default to C99 (I think) which wouldn’t happen with the compilers you tried.

[scoder]

Yes, that looks wrong. I think we have to test the input argument upfront, not the result.

The check is generated in ExprNodes.py, SimpleCallNode.generate_result_code(). I think it should use a dedicated expression node instead, to be inserted into the tree in analyse_c_function_call(). The fact that the safety check is currently implemented directly in the code generation of SimpleCallNode is rather a hack.