Build failure on FreeBSD 14 with clang 16 and python3.9

[n12i]

BUG/PROBLEM REPORT / FEATURE REQUEST

What I did:

mkdir Plone6 && cd Plone6
virtuanenv-3.9 zinstance
cd zinstance
bin/pip install zc.buildout
cat >buildout.cfg <<EOF
[buildout]
extends =
https://dist.plone.org/release/6-latest/versions.cfg

parts =
instance

[instance]
recipe = plone.recipe.zope2instance
user = admin:admin
http-address = 8080
eggs =
Plone
EOF
./bin/buildout

What I expect to happen:

Generated script '.../Plone6/zinstance/bin/instance'.
Generated interpreter '.../Plone6/zinstance/parts/instance/bin/interpreter'.

What actually happened:

[snip]
creating build/temp.freebsd-14.0-RELEASE-p6-amd64-cpython-39/src/AccessControl
cc -pthread -Wno-unused-result -Wsign-compare -Wunreachable-code -DNDEBUG -O2 -pipe -fstack-protector-strong -fno-strict-aliasing -fPIC -Iinclude -Isrc -I/usr/home/nakaji/Plone6/zinstance/include -I/usr/local/include/python3.9 -c src/AccessControl/cAccessControl.c -o build/temp.freebsd-14.0-RELEASE-p6-amd64-cpython-39/src/AccessControl/cAccessControl.o
src/AccessControl/cAccessControl.c:428:2: error: incompatible pointer to integer conversion initializing 'Py_ssize_t' (aka 'long') with an expression of type 'void ' [-Wint-conversion]
NULL, / tp_print */
^~~~
/usr/include/sys/_null.h:32:14: note: expanded from macro 'NULL'
#define NULL ((void *)0)
^~~~~~~~~~~
src/AccessControl/cAccessControl.c:487:2: error: incompatible pointer to integer conversion initializing 'Py_ssize_t' (aka 'long') with an expression of type 'void ' [-Wint-conversion]
NULL, / tp_print */
^~~~
/usr/include/sys/_null.h:32:14: note: expanded from macro 'NULL'
#define NULL ((void *)0)
^~~~~~~~~~~
src/AccessControl/cAccessControl.c:546:2: error: incompatible pointer to integer conversion initializing 'Py_ssize_t' (aka 'long') with an expression of type 'void ' [-Wint-conversion]
NULL, / tp_print */
^~~~
/usr/include/sys/_null.h:32:14: note: expanded from macro 'NULL'
#define NULL ((void *)0)
^~~~~~~~~~~
src/AccessControl/cAccessControl.c:616:2: error: incompatible pointer to integer conversion initializing 'Py_ssize_t' (aka 'long') with an expression of type 'void ' [-Wint-conversion]
NULL, / tp_print */
^~~~
/usr/include/sys/_null.h:32:14: note: expanded from macro 'NULL'
#define NULL ((void *)0)
^~~~~~~~~~~
/usr/include/sys/_null.h:32:14: note: expanded from macro 'NULL'
#define NULL ((void *)0)
^~~~~~~~~~~
src/AccessControl/cAccessControl.c:546:2: error: incompatible pointer to integer conversion initializing 'Py_ssize_t' (aka 'long') with an expression of type 'void ' [-Wint-conversion]
NULL, / tp_print */
^~~~
/usr/include/sys/_null.h:32:14: note: expanded from macro 'NULL'
#define NULL ((void *)0)
^~~~~~~~~~~
src/AccessControl/cAccessControl.c:616:2: error: incompatible pointer to integer conversion initializing 'Py_ssize_t' (aka 'long') with an expression of type 'void ' [-Wint-conversion]
NULL, / tp_print */
^~~~
/usr/include/sys/_null.h:32:14: note: expanded from macro 'NULL'
#define NULL ((void *)0)
^~~~~~~~~~~
4 errors generated.
error: command '/usr/bin/cc' failed with exit code 1
[end of output]

note: This error originates from a subprocess, and is likely not a problem with pip.
ERROR: Failed building wheel for AccessControl
ERROR: Could not build wheels for AccessControl, which is required to install pyproject.toml-based projects
An error occurred when trying to install /tmp/tmpzakznsmqget_dist/AccessControl-6.3.tar.gz. Look above this message for any errors that were output by pip install.

What version of Python and Zope/Addons I am using:

% freebsd-version
14.0-RELEASE-p6
% ./bin/python --version
Python 3.9.18
% cc -v
FreeBSD clang version 16.0.6 (https://github.com/llvm/llvm-project.git llvmorg-16.0.6-0-g7cbf1a259152)
Target: x86_64-unknown-freebsd14.0
Thread model: posix
InstalledDir: /usr/bin

[icemac]

I would have expected that one of our pre-built wheels gets installed.
What happens if you create a new virtual environment and install AccessControl there via pip?

[n12i]

(modified, sorry)
% virtualenv-3.9 accesscontrol
% cd accesscontrol
% ./bin/pip install -v --no-cache-dir AccessControl
got the same NULL error.

cc -pthread -Wno-unused-result -Wsign-compare -Wunreachable-code -DNDEBUG -O2
-pipe -fstack-protector-strong -fno-strict-aliasing -fPIC -Iinclude -Isrc -I/usr
/home/nakaji/Plone6/accesscontrol/include -I/usr/local/include/python3.9 -c src/
AccessControl/cAccessControl.c -o build/temp.freebsd-13.3-RELEASE-p1-amd64-cpyth
on-39/src/AccessControl/cAccessControl.o
src/AccessControl/cAccessControl.c:428:2: error: incompatible pointer to integ
er conversion initializing 'Py_ssize_t' (aka 'long') with an expression of type
'void ' [-Wint-conversion]
428 | NULL, / tp_print */
| ^~~~
/usr/include/sys/_null.h:32:14: note: expanded from macro 'NULL'
32 | #define NULL ((void *)0)
| ^~~~~~~~~~~
(snip)

Clang 16 says it is an error, and gcc13 just warns.

[n12i]

According to the error/warn message, I changed NULL to 0 and the build was successful.
Patch: https://www.heimat.gr.jp/~nakaji/FreeBSD/AccessControl.diff

[icemac]

@n12i Nice finding!
Could you please create a pull request with your diff to see the result on the systems we automatically test?

[d-maurer]

NAKAJI Hiroyuki wrote at 2024-4-24 22:29 -0700:

According to the error/warn message, I changed NULL to 0 and the build was successful. Patch: https://www.heimat.gr.jp/~nakaji/FreeBSD/AccessControl.diff

If I have understood your initial report correctly, then the problem has been associated with a line associated with `tp_print` (a function pointer field) but the compiler expected a size field. This would be something serious -- not really resolved by replacing "NULL" by "0".

[n12i]

If I have understood your initial report correctly, then the problem has been associated with a line associated with tp_print (a function pointer field) but the compiler expected a size field. This would be something serious -- not really resolved by replacing "NULL" by "0".

Agree. My patch can compile cAccessControl.c but I'm not sure if it works correctly.

Similar to these pull requests?
tgalal/python-axolotl-curve25519#26
tgalal/python-axolotl-curve25519#28
python-postgres/fe#125

[icemac]

There is now #150 merged, could you please try whether this also fixes your problem?

[davisagli]

I have a project where I can't use the fix in #150 because it's an old project that requires an older major version of AccessControl.

Aside from the problem of casting a pointer to an integer, which is what #150 fixed, I think the problem started happening because clang made a change to raise an error instead of a warning in this scenario: https://reviews.llvm.org/D129881

It might be possible to build an older version of AccessControl by setting CFLAGS="-Wno-error=int-conversion" but I'm waiting for feedback from my colleague on whether this works.

[jessesnyder]

I can confirm that setting CFLAGS="-Wno-error=int-conversion" allowed me to build AccessControl-4.3-py3.8-macosx-14.5-arm64.egg.

[n12i]

There is now #150 merged, could you please try whether this also fixes your problem?

Thanks. This fixes my problem with one waning generated.

src/AccessControl/cAccessControl.c:2202:7: warning: code will never be executed [-Wunreachable-code]
2202 | unauthErr(name, v);
| ^~~~~~~~~
1 warning generated.

[icemac]

@n12i I think this warning was already there before.