Fails to build with GCC 15 due to -Wincompatible-pointer-types

[glaubitz]

With GCC 15, function declarations with no parameters can no longer be used for functions that take parameters.

As a result, pyo fails to build from source with GCC 15 with the following error:

[   13s] gcc -fno-strict-overflow -Wsign-compare -DNDEBUG -O2 -Wall -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=3 -fstack-protector-strong -funwind-tables -fasynchronous-unwind-tables -fstack-clash-protection -Werror=return-type -g -DOPENSSL_LOAD_CONF -fwrapv -fno-semantic-interposition -O2 -Wall -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=3 -fstack-protector-strong -funwind-tables -fasynchronous-unwind-tables -fstack-clash-protection -Werror=return-type -g -IVendor/ -O2 -Wall -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=3 -fstack-protector-strong -funwind-tables -fasynchronous-unwind-tables -fstack-clash-protection -Werror=return-type -g -IVendor/ -O2 -Wall -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=3 -fstack-protector-strong -funwind-tables -fasynchronous-unwind-tables -fstack-clash-protection -Werror=return-type -flto=auto -g -fPIC -DUSE_PORTAUDIO -DUSE_PORTMIDI -DUSE_OSC -DUSE_JACK -DJACK_NEW_API -Iinclude -I/usr/include -I/usr/local/include -I/usr/include/python3.12 -c src/engine/dummymodule.c -o build/temp.linux-x86_64-cpython-312/src/engine/dummymodule.o -Wno-strict-prototypes -Wno-strict-aliasing -O3 -g0 -DNDEBUG
[   13s] src/engine/dummymodule.c: In function ‘Dummy_setProcMode’:
[   13s] src/engine/dummymodule.c:48:35: error: assignment to ‘void (*)(void)’ from incompatible pointer type ‘void (*)(Dummy *)’ [-Wincompatible-pointer-types]
[   13s]    48 |             self->muladd_func_ptr = Dummy_postprocessing_ii;
[   13s]       |                                   ^
[   13s] src/engine/dummymodule.c:29:13: note: ‘Dummy_postprocessing_ii’ declared here
[   13s]    29 | static void Dummy_postprocessing_ii(Dummy *self) { POST_PROCESSING_II };
[   13s]       |             ^~~~~~~~~~~~~~~~~~~~~~~
[   13s] src/engine/dummymodule.c:52:35: error: assignment to ‘void (*)(void)’ from incompatible pointer type ‘void (*)(Dummy *)’ [-Wincompatible-pointer-types]
[   13s]    52 |             self->muladd_func_ptr = Dummy_postprocessing_ai;
[   13s]       |                                   ^
[   13s] src/engine/dummymodule.c:30:13: note: ‘Dummy_postprocessing_ai’ declared here
[   13s]    30 | static void Dummy_postprocessing_ai(Dummy *self) { POST_PROCESSING_AI };
[   13s]       |             ^~~~~~~~~~~~~~~~~~~~~~~

[belangeo]

That would be too much of a refactor to do this at the moment (not even sure how I will handle that)... I can repro in godbolt, but Apple clang seems to be more compliant than gcc! Is it working on your side if you add "-Wno-incompatible-pointer-types" in the extra_compile_args?