Migrate from setuptools to meson-python build backend

.github/workflows/main.yml

@@ -118,7 +118,7 @@ jobs:
         needs: [dist]
 
 env:
-    # Ubuntu packages to install so that the project's "setup.py sdist" can succeed
+    # Ubuntu packages to install so that building the sdist can succeed
     DIST_PREREQ: libpari-dev pari-doc libbz2-dev bzip2
     # Name of this project in the Sage distribution
     SPKG:        cypari

.install-pari.sh

@@ -8,9 +8,9 @@ if [ "$URLDIR" = "" ]; then
     URLDIR=OLD/${PURE_VERSION%.*}
 fi
 
-PARI_URL="http://pari.math.u-bordeaux.fr/pub/pari/$URLDIR"
-PARI_URL1="http://pari.math.u-bordeaux.fr/pub/pari/unix"
-PARI_URL2="http://pari.math.u-bordeaux.fr/pub/pari/unstable"
+PARI_URL="https://pari.math.u-bordeaux.fr/pub/pari/$URLDIR"
+PARI_URL1="https://pari.math.u-bordeaux.fr/pub/pari/unix"
+PARI_URL2="https://pari.math.u-bordeaux.fr/pub/pari/unstable"
 
 # Download PARI sources
 wget --no-verbose "$PARI_URL/$PARI_VERSION.tar.gz" -O pari.tgz || wget --no-verbose "$PARI_URL1/pari-$PARI_VERSION.tar.gz" -O pari.tgz || wget --no-verbose "$PARI_URL2/pari-$PARI_VERSION.tar.gz" -O pari.tgz

README.rst

@@ -5,7 +5,7 @@ CyPari 2
     :target: https://cypari2.readthedocs.io/en/latest/?badge=latest
     :alt: Documentation Status
 
-A Python interface to the number theory library `PARI/GP <http://pari.math.u-bordeaux.fr/>`_.
+A Python interface to the number theory library `PARI/GP <https://pari.math.u-bordeaux.fr/>`_.
 
 Installation
 ------------
@@ -42,14 +42,10 @@ From source with pip
 
 Requirements:
 
-- PARI/GP >= 2.9.4 (header files and library); see
+  PARI/GP >= 2.9.4 (header files and library); see
   https://doc.sagemath.org/html/en/reference/spkg/pari#spkg-pari
   for availability in distributions (GNU/Linux, conda-forge, Homebrew, FreeBSD),
   or install from source.
-- Python >= 3.9
-- pip
-- `cysignals <https://pypi.python.org/pypi/cysignals/>`_ >= 1.11.3
-- Cython >= 3.0
 
 Install cypari2 via the Python Package Index (PyPI) via
 
@@ -136,13 +132,25 @@ same computations be done via
     >>> pari.centerlift(pari.lift(fq))
     [x - t, 1; x + (t^2 + t - 1), 1; x + (-t^2 - 1), 1]
 
-The complete documentation of cypari2 is available at http://cypari2.readthedocs.io and
-the PARI/GP documentation at http://pari.math.u-bordeaux.fr/doc.html
+The complete documentation of cypari2 is available at https://cypari2.readthedocs.io and
+the PARI/GP documentation at https://pari.math.u-bordeaux.fr/doc.html
 
-Contributing
-------------
+Contributing & Development
+--------------------------
 
 CyPari 2 is maintained by the SageMath community.
 
 Open issues or submit pull requests at https://github.com/sagemath/cypari2
 and join https://groups.google.com/group/sage-devel to discuss.
+
+To get started with development, you can set up an environment using Conda 
+as follows:
+
+::
+    $ conda create -n cypari2-dev python cython pari=*=*_pthread ninja meson-python cysignals c-compiler
+    $ conda activate cypari2-dev
+
+Afterwards, you can build and install the package in editable mode: 
+
+::
+    $ pip install -e . --no-build-isolation

autogen/args.py

@@ -9,7 +9,7 @@
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation, either version 2 of the License, or
 # (at your option) any later version.
-#                  http://www.gnu.org/licenses/
+#                  https://www.gnu.org/licenses/
 #*****************************************************************************
 
 from __future__ import unicode_literals

autogen/parser.py

@@ -9,16 +9,18 @@
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation, either version 2 of the License, or
 # (at your option) any later version.
-#                  http://www.gnu.org/licenses/
+#                  https://www.gnu.org/licenses/
 #*****************************************************************************
 
 from __future__ import absolute_import, unicode_literals
 
-import os, re, io
+import io
+import os
+import re
 
 from .args import pari_arg_types
-from .ret import pari_ret_types
 from .paths import pari_share
+from .ret import pari_ret_types
 
 paren_re = re.compile(r"[(](.*)[)]")
 argname_re = re.compile(r"[ {]*&?([A-Za-z_][A-Za-z0-9_]*)")

autogen/paths.py

@@ -9,17 +9,15 @@
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation, either version 2 of the License, or
 # (at your option) any later version.
-#                  http://www.gnu.org/licenses/
+#                  https://www.gnu.org/licenses/
 #*****************************************************************************
 
 from __future__ import absolute_import, unicode_literals
 
 import os
 import shutil
-
 from glob import glob
 
-
 gppath = shutil.which("gp")
 
 if gppath is None:
@@ -43,7 +41,7 @@ def pari_share():
     """
     if "PARI_SHARE" in os.environ:
         return os.environ["PARI_SHARE"]
-    from subprocess import Popen, PIPE
+    from subprocess import PIPE, Popen
     if not gppath:
         raise EnvironmentError("cannot find an installation of PARI/GP: make sure that the 'gp' program is in your $PATH")
     # Ignore GP_DATA_DIR environment variable

autogen/ret.py

@@ -9,11 +9,12 @@
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation, either version 2 of the License, or
 # (at your option) any later version.
-#                  http://www.gnu.org/licenses/
+#                  https://www.gnu.org/licenses/
 #*****************************************************************************
 
 from __future__ import unicode_literals
 
+
 class PariReturn(object):
     """
     This class represents the return value of a PARI call.

cypari2/convert.pyx

@@ -15,7 +15,7 @@ PARI integers are stored as an array of limbs of type ``pari_ulong``
 (GMP or native), this array is stored little-endian or big-endian.
 This is encapsulated in macros like ``int_W()``:
 see section 4.5.1 of the
-`PARI library manual <http://pari.math.u-bordeaux.fr/pub/pari/manuals/2.7.0/libpari.pdf>`_.
+`PARI library manual <https://pari.math.u-bordeaux.fr/pub/pari/manuals/2.7.0/libpari.pdf>`_.
 
 Python integers of type ``int`` are just C longs. Python integers of
 type ``long`` are stored as a little-endian array of type ``digit``

cypari2/custom_block.pyx

@@ -1,10 +1,8 @@
-# distutils: libraries = gmp pari
-
 #*****************************************************************************
 #  Distributed under the terms of the GNU General Public License (GPL)
 #  as published by the Free Software Foundation; either version 2 of
 #  the License, or (at your option) any later version.
-#                  http://www.gnu.org/licenses/
+#                  https://www.gnu.org/licenses/
 #*****************************************************************************
 
 from cysignals.signals cimport add_custom_signals

cypari2/gen.pyx

@@ -1789,9 +1789,9 @@ cdef class Gen(Gen_base):
         while sp[0] == c'0':
             sp = sp + 1
         sp -= 1
-        sp[0] = 'x'
+        sp[0] = c'x'
         sp -= 1
-        sp[0] = '0'
+        sp[0] = c'0'
         if signe(x) < 0:
             sp -= 1
             sp[0] = c'-'
@@ -3639,7 +3639,7 @@ cdef class Gen(Gen_base):
         >>> G.galoissubfields(flag=2, v='z')[3]
         [...^2 + 2, Mod(x^3 + x, x^4 + 1), [x^2 - z*x - 1, x^2 + z*x - 1]]
 
-        .. _galoissubfields: http://pari.math.u-bordeaux.fr/dochtml/html.stable/Functions_related_to_general_number_fields.html#galoissubfields
+        .. _galoissubfields: https://pari.math.u-bordeaux.fr/dochtml/html.stable/Functions_related_to_general_number_fields.html#galoissubfields
         """
         sig_on()
         return new_gen(galoissubfields(self.g, flag, get_var(v)))

cypari2/meson.build

@@ -0,0 +1,43 @@
+py.install_sources(
+  '__init__.py',
+  'closure.pxd',
+  'convert.pxd',
+  'gen.pxd',
+  'handle_error.pxd',
+  'pari_instance.pxd',
+  'paridecl.pxd',
+  'paripriv.pxd',
+  'pycore_long.pxd',
+  'stack.pxd',
+  'string_utils.pxd',
+  'types.pxd',
+  'cypari.h',
+  'pycore_long.h',
+  'auto_paridecl.pxd',
+  'auto_gen.pxi',
+  'auto_instance.pxi',
+  subdir: 'cypari2'
+)
+
+
+extension_data = {
+  'closure': files('closure.pyx'),
+  'stack': files('stack.pyx'),
+  'custom_block': files('custom_block.pyx'),
+  'convert': files('convert.pyx'),
+  'string_utils': files('string_utils.pyx'),
+  'handle_error': files('handle_error.pyx'),
+  'gen': files('gen.pyx'),
+  'pari_instance': files('pari_instance.pyx')
+}
+
+foreach name, pyx : extension_data
+  py.extension_module(
+    name,
+    sources: pyx,
+    subdir: 'cypari2',
+    install: true,
+    dependencies: [cysignals, pari],
+  )
+endforeach
+

cypari2/paridecl.pxd

@@ -1,4 +1,3 @@
-# distutils: libraries = gmp pari
 """
 Declarations for non-inline functions from PARI.
 

cypari2/paripriv.pxd

@@ -1,4 +1,3 @@
-# distutils: libraries = gmp pari
 """
 Declarations for private functions from PARI
 

cypari2/stack.pyx

@@ -11,7 +11,7 @@ Memory management for Gens on the PARI stack or the heap
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation, either version 2 of the License, or
 # (at your option) any later version.
-#                  http://www.gnu.org/licenses/
+#                  https://www.gnu.org/licenses/
 # ****************************************************************************
 
 cimport cython

meson.build

@@ -0,0 +1,53 @@
+project('cypari2', 
+  ['c', 'cython'],
+  version: files('VERSION'),
+  license: 'GPL v2+',
+  default_options: ['c_std=c17', 'python.install_env=auto'],
+  meson_version: '>=1.2',
+)
+
+# Python module
+# https://mesonbuild.com/Python-module.html
+py = import('python').find_installation(pure: false)
+
+# Compilers
+cc = meson.get_compiler('c')
+cython = meson.get_compiler('cython')
+# Workaround as described in https://cython.readthedocs.io/en/latest/src/userguide/special_methods.html#arithmetic-methods
+add_project_arguments('-X c_api_binop_methods=True', language: 'cython')
+
+# Dependencies  
+inc_cysignals = run_command(
+  py,
+  [
+    '-c',
+    '''
+from os.path import relpath
+import cysignals
+path = cysignals.__file__.replace('__init__.py', '')
+try:
+  print(relpath(path))
+except Exception:
+  print(path)
+    '''.strip(),
+  ],
+  check: true,
+).stdout().strip()
+cysignals = declare_dependency(include_directories: inc_cysignals)
+# Cannot be found via pkg-config
+pari = cc.find_library('pari', required: true)
+
+# Run code generation step
+code_gen_result = run_command(
+  py.full_path(), '-c',
+  '''
+import sys
+sys.path.insert(0, ".")
+from autogen import rebuild
+rebuild(force=True)
+print("Code generation successful")
+  ''',
+  check: true
+)
+
+subdir('cypari2')

pyproject.toml

@@ -1,36 +1,23 @@
 [build-system]
-requires = [
-    "setuptools",
-    "Cython>=3.0",
-    "cysignals>=1.11.3",
-]
-# We need access to the autogen package at build time.
-# Hence we declare a custom build backend.
-build-backend = "_custom_build_meta"  # just re-exports setuptools.build_meta definitions
-backend-path = ["."]
+requires = ["meson-python>=0.18.0", "cython>=3.0", "cysignals>=1.11.3"]
+build-backend = "mesonpy"
 
 [project]
 name = "cypari2"
 description = "A Python interface to the number theory library PARI/GP"
 authors = [
-    {name = "Luca De Feo, Vincent Delecroix, Jeroen Demeyer, Vincent Klein"},
+    { name = "Luca De Feo, Vincent Delecroix, Jeroen Demeyer, Vincent Klein" },
 ]
 maintainers = [
-    {name = "SageMath developers", email = "[email protected]"},
-]
-dependencies = [
-    "cysignals>=1.11.3",
+    { name = "SageMath developers", email = "[email protected]" },
 ]
+dependencies = ["cysignals>=1.11.3"]
 requires-python = ">=3.9"
 readme = "README.rst"
-license = {text = "GNU General Public License, version 2 or later"}
+license = "GPL-2.0-or-later"
+license-files = ["LICENSE"]
 keywords = ["PARI/GP number theory"]
-dynamic = [
-    "version",
-]
+dynamic = ["version"]
 
 [project.urls]
 Homepage = "https://github.com/sagemath/cypari2"
-
-[tool.setuptools.dynamic]
-version = {file = "VERSION"}