RFE: please provide cython 3.x support

[kloczek]

https://github.com/MagicStack/asyncpg/blob/master/pyproject.toml#L45-L49

[befeleme]

We've built asyncpg in Fedora Linux with Cython 3.0.5 successfully, although with quite a few warnings.

Build warnings

  asyncpg/pgproto/pgproto.c: In function ‘__Pyx_PyLong_AbsNeg’:
  asyncpg/pgproto/pgproto.c:46832:97: warning: unsigned conversion from ‘int’ to ‘uintptr_t’ {aka ‘long unsigned int’} changes value from ‘-4’ to ‘18446744073709551612’ [-Wsign-conversion]
  46832 |             ((PyLongObject*)copy)->long_value.lv_tag = ((PyLongObject*)copy)->long_value.lv_tag & ~_PyLong_SIGN_MASK;
        |                                                                                                 ^
  In file included from /usr/include/python3.12/internal/pycore_frame.h:9,
                   from asyncpg/pgproto/pgproto.c:49619:
  /usr/include/python3.12/internal/pycore_code.h: In function ‘write_varint’:
  /usr/include/python3.12/internal/pycore_code.h:362:12: warning: conversion from ‘unsigned int’ to ‘uint8_t’ {aka ‘unsigned char’} may change value [-Wconversion]
    362 |     *ptr = val;
        |            ^~~
  /usr/include/python3.12/internal/pycore_code.h: In function ‘write_signed_varint’:
  /usr/include/python3.12/internal/pycore_code.h:375:30: warning: conversion to ‘unsigned int’ from ‘int’ may change the sign of the result [-Wsign-conversion]
    375 |     return write_varint(ptr, val);
        |                              ^~~
  /usr/include/python3.12/internal/pycore_code.h: In function ‘write_location_entry_start’:
  /usr/include/python3.12/internal/pycore_code.h:382:12: warning: conversion from ‘int’ to ‘uint8_t’ {aka ‘unsigned char’} may change value [-Wconversion]
    382 |     *ptr = 128 | (code << 3) | (length - 1);
        |            ^~~
  /usr/include/python3.12/internal/pycore_code.h: In function ‘adaptive_counter_bits’:
  /usr/include/python3.12/internal/pycore_code.h:423:45: warning: conversion from ‘int’ to ‘uint16_t’ {aka ‘short unsigned int’} may change value [-Wconversion]
    423 |     return (value << ADAPTIVE_BACKOFF_BITS) |
        |            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^
    424 |         (backoff & ((1<
asyncpg/protocol/protocol.c: In function ‘__Pyx_PyUnicode_AsDouble_WithSpaces’:

asyncpg/protocol/protocol.c:4194:58: warning: conversion to ‘long unsigned int’ from ‘Py_ssize_t’ {aka ‘long int’} may change the sign of the result [-Wsign-conversion]

4194 |         char number = (char) PyMem_Malloc((length + 1) * sizeof(char));

|                                                          ^

In file included from /usr/include/python3.12/internal/pycore_frame.h:9,

from asyncpg/protocol/protocol.c:105482:

/usr/include/python3.12/internal/pycore_code.h: In function ‘write_varint’:

/usr/include/python3.12/internal/pycore_code.h:362:12: warning: conversion from ‘unsigned int’ to ‘uint8_t’ {aka ‘unsigned char’} may change value [-Wconversion]

362 |     *ptr = val;

|            ^~~

/usr/include/python3.12/internal/pycore_code.h: In function ‘write_signed_varint’:

/usr/include/python3.12/internal/pycore_code.h:375:30: warning: conversion to ‘unsigned int’ from ‘int’ may change the sign of the result [-Wsign-conversion]

375 |     return write_varint(ptr, val);

|                              ^~~

/usr/include/python3.12/internal/pycore_code.h: In function ‘write_location_entry_start’:

/usr/include/python3.12/internal/pycore_code.h:382:12: warning: conversion from ‘int’ to ‘uint8_t’ {aka ‘unsigned char’} may change value [-Wconversion]

382 |     *ptr = 128 | (code << 3) | (length - 1);

|            ^~~

/usr/include/python3.12/internal/pycore_code.h: In function ‘adaptive_counter_bits’:

/usr/include/python3.12/internal/pycore_code.h:423:45: warning: conversion from ‘int’ to ‘uint16_t’ {aka ‘short unsigned int’} may change value [-Wconversion]

423 |     return (value << ADAPTIVE_BACKOFF_BITS) |

|            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^

424 |         (backoff & ((1<<ADAPTIVE_BACKOFF_BITS)-1));

|         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

/usr/include/python3.12/internal/pycore_code.h: In function ‘adaptive_counter_backoff’:

/usr/include/python3.12/internal/pycore_code.h:446:26: warning: conversion to ‘unsigned int’ from ‘int’ may change the sign of the result [-Wsign-conversion]

446 |     unsigned int value = (1 << backoff) - 1;

|                          ^

/usr/include/python3.12/internal/pycore_code.h:447:34: warning: conversion to ‘int’ from ‘unsigned int’ may change the sign of the result [-Wsign-conversion]

447 |     return adaptive_counter_bits(value, backoff);

|                                  ^~~~~

/usr/include/python3.12/internal/pycore_code.h:447:41: warning: conversion to ‘int’ from ‘unsigned int’ may change the sign of the result [-Wsign-conversion]

447 |     return adaptive_counter_bits(value, backoff);

|                                         ^~~~~~~

asyncpg/protocol/protocol.c: In function ‘__Pyx__PyBytes_AsDouble’:

asyncpg/protocol/protocol.c:108361:58: warning: conversion to ‘long unsigned int’ from ‘Py_ssize_t’ {aka ‘long int’} may change the sign of the result [-Wsign-conversion]

108361 |         char number = (char) PyMem_Malloc((digits + 1) * sizeof(char));

|                                                          ^

gcc -fno-strict-overflow -Wsign-compare -DDYNAMIC_ANNOTATIONS_ENABLED=1 -DNDEBUG -fcf-protection -fexceptions -fcf-protection -fexceptions -fcf-protection -fexceptions -O2 -flto=auto -ffat-lto-objects -fexceptions -g -grecord-gcc-switches -pipe -Wall -Werror=format-security -Werror=implicit-function-declaration -Werror=implicit-int -Wp,-U_FORTIFY_SOURCE,-D_FORTIFY_SOURCE=3 -Wp,-D_GLIBCXX_ASSERTIONS -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -fstack-protector-strong -specs=/usr/lib/rpm/redhat/redhat-annobin-cc1 -m64 -mtune=generic -fasynchronous-unwind-tables -fstack-clash-protection -fcf-protection -fno-omit-frame-pointer -mno-omit-leaf-frame-pointer -fPIC -Iasyncpg/pgproto -Iasyncpg/pgproto/ -I/usr/include/python3.12 -c asyncpg/protocol/record/recordobj.c -o build/temp.linux-x86_64-cpython-312/asyncpg/protocol/record/recordobj.o -O2 -fsigned-char -Wall -Wsign-compare -Wconversion

asyncpg/protocol/record/recordobj.c: In function ‘record_dealloc’:

asyncpg/protocol/record/recordobj.c:101:5: warning: ‘UsingDeprecatedTrashcanMacro’ is deprecated [-Wdeprecated-declarations]

101 |     Py_TRASHCAN_SAFE_BEGIN(o)

|     ^~~~~~~~~~~~~~~~~~~~~~

[kloczek]

After trimming build dependencies using below patch

--- a/pyproject.toml
+++ b/pyproject.toml
@@ -50,7 +50,7 @@
     "setuptools>=60",
     "wheel",

-    "Cython(>=0.29.24,<3.0.0)"
+    "Cython(>=3.0.0)"
 ]
 build-backend = "setuptools.build_meta"

--- a/setup.py
+++ b/setup.py
@@ -25,7 +25,7 @@
 from setuptools.command import build_ext as setuptools_build_ext


-CYTHON_DEPENDENCY = 'Cython(>=0.29.24,<0.30.0)'
+CYTHON_DEPENDENCY = 'Cython(>=0.30.0)'

 CFLAGS = ['-O2']
 LDFLAGS = []

Looks like build is OK.

Closing.

[musicinmybrain]

Just noting that the upper-bound excluding Cython 3.x is still present in master:

asyncpg/pyproject.toml

Line 62 in 1aab209

"Cython(>=0.29.24,<3.0.0)"

asyncpg/setup.py

Line 28 in 1aab209

CYTHON_DEPENDENCY = 'Cython(>=0.29.24,<0.30.0)'