[BUG] `cythonize` does not work on 3.1.0 + gcc 4.8

[oraluben]

Describe the bug

As title.

Example took from https://github.com/pypa/auditwheel/tree/main/tests/integration/sample_extension

git clone https://github.com/pypa/auditwheel.git
cd auditwheel
docker run -v `pwd`:/auditwheel_src -ti quay.io/pypa/manylinux1_x86_64
/opt/_internal/cpython-3.9.19/bin/python -mvenv /venv
source /venv/bin/activate
pip install cython==3.1.0
cd /auditwheel_src/tests/integration/sample_extension/
# This works
cython src/sample_extension.pyx
# This fail
python setup.py develop

Error:

running develop
running egg_info
creating sample_extension.egg-info
writing sample_extension.egg-info/PKG-INFO
writing dependency_links to sample_extension.egg-info/dependency_links.txt
writing top-level names to sample_extension.egg-info/top_level.txt
writing manifest file 'sample_extension.egg-info/SOURCES.txt'
reading manifest file 'sample_extension.egg-info/SOURCES.txt'
writing manifest file 'sample_extension.egg-info/SOURCES.txt'
running build_ext
building 'sample_extension' extension
creating build
creating build/temp.linux-x86_64-3.9
creating build/temp.linux-x86_64-3.9/src
gcc -pthread -Wno-unused-result -Wsign-compare -DNDEBUG -g -fwrapv -O3 -Wall -fPIC -I/venv/include -I/opt/_internal/cpython-3.9.19/include/python3.9 -c src/sample_extension.c -o build/temp.linux-x86_64-3.9/src/sample_extension.o
src/sample_extension.c: In function ‘__pyx_pw_16sample_extension_1test_func’:
src/sample_extension.c:2330:7: error: ‘for’ loop initial declarations are only allowed in C99 mode
       for (Py_ssize_t i = __pyx_nargs; i < 1; i++) {
       ^
src/sample_extension.c:2330:7: note: use option -std=c99 or -std=gnu99 to compile your code
src/sample_extension.c:2347:3: error: ‘for’ loop initial declarations are only allowed in C99 mode
   for (Py_ssize_t __pyx_temp=0; __pyx_temp < (Py_ssize_t)(sizeof(values)/sizeof(values[0])); ++__pyx_temp) {
   ^
src/sample_extension.c:2357:19: error: redefinition of ‘__pyx_temp’
   for (Py_ssize_t __pyx_temp=0; __pyx_temp < (Py_ssize_t)(sizeof(values)/sizeof(values[0])); ++__pyx_temp) {
                   ^
src/sample_extension.c:2347:19: note: previous definition of ‘__pyx_temp’ was here
   for (Py_ssize_t __pyx_temp=0; __pyx_temp < (Py_ssize_t)(sizeof(values)/sizeof(values[0])); ++__pyx_temp) {
                   ^
src/sample_extension.c:2357:3: error: ‘for’ loop initial declarations are only allowed in C99 mode
   for (Py_ssize_t __pyx_temp=0; __pyx_temp < (Py_ssize_t)(sizeof(values)/sizeof(values[0])); ++__pyx_temp) {
   ^
src/sample_extension.c: In function ‘__Pyx_ParseKeywordsTuple’:
src/sample_extension.c:3972:5: error: ‘for’ loop initial declarations are only allowed in C99 mode
     for (Py_ssize_t pos = 0; pos < num_kwargs; pos++) {
     ^
src/sample_extension.c: In function ‘__Pyx_PyCode_New’:
src/sample_extension.c:6876:5: error: ‘for’ loop initial declarations are only allowed in C99 mode
     for (Py_ssize_t i=0; i < var_count; i++) {
     ^
error: command '/opt/rh/devtoolset-2/root/usr/bin/gcc' failed with exit code 1

Code to reproduce the behaviour:

No response

Expected behaviour

No response

OS

Linux

Python version

3.9.19

Cython version

3.1.0 (3.0.11 works)

Additional context

No response

[scoder]

Cython 3.1 requires a C99 compatible C compiler.

[da-woods]

GCC 4.8 looks to support C99. You just have to turn it on with a command line option. So there really isn't any issue here at all

[oraluben]

@da-woods would you mind to show how to enable C99 in setup.py or similar approach? I was imaging cython could detect GCC version and add flag for me.

[da-woods]

It's usually just extra_compile_args=["--std=gnu99"] or something every similar to that.