BLD: use the CPython Limited C API, and hence the Stable ABI

This will build an `abi3` wheel per platform, which can be used
for multiple (with-GIL) Python interpreter versions.

Author: rgommers

meson.build

@@ -3,11 +3,15 @@ project(
   'c', 'cython',
   version: '1.10.0.dev0',
   license: 'MIT',
-  meson_version: '>= 1.1.0',
+  meson_version: '>= 1.5.0',
   default_options: [
     'buildtype=debugoptimized',
     'b_ndebug=if-release',
     'c_std=c17',
+    # We default to false here (so produce wheels like cp314), and can opt into
+    # producing abi3 wheels. The setting in pyproject.toml is
+    # `limited-api=true`, but this default will ensure it is opt-in:
+    'python.allow_limited_api=false',
   ],
 )
 

pyproject.toml

@@ -60,6 +60,8 @@ documentation = "https://pywavelets.readthedocs.io/"
 config-settings = {setup-args = ["--vsenv"]}
 before-build = "bash {project}/util/cibw_before_build_win.sh"
 
+[tool.meson-python]
+limited-api = true
 
 [tool.ruff]
 line-length = 88

pywt/_extensions/meson.build

@@ -106,6 +106,7 @@ foreach pyx_file: pyx_files
   py.extension_module(pyx_file[0],
     [cython_gen.process(pyx_file[1])],
     c_args : c_args,
+    limited_api: '3.12',
     include_directories : 'c',
     dependencies : [np_dep, cy_deps],
     link_with : libc_wt,