build: enable building with the limited API

meson.build

@@ -2,7 +2,8 @@ project(
   'python-flint',
   'cython',
   'c',
-  meson_version : '>=1.1',
+  meson_version : '>=1.3.0',
+  default_options: ['python.allow_limited_api=false'],
 )
 #
 # The minimum versions are because we know that it will not work with earlier
@@ -83,15 +84,20 @@ add_project_arguments(
     language : 'cython'
 )
 
+# Only used if python.allow_limited_api is true (not the default)
+limited_api_version = get_option('limited_api_version')
+
 # Enable free-threading if Cython is new enough. The check should be
 # >= 3.1.0a1 but meson gets confused by the a1 alpha release suffix.
 # so we go with >= 3.1 (which will be correct once 3.1 is released).
 cy = meson.get_compiler('cython')
-if cy.version().version_compare('>=3.1')
+if get_option('python.allow_limited_api')
+  message('Using Python limited API version ' + limited_api_version)
+elif cy.version().version_compare('>=3.1')
   message('Enabling freethreading')
   add_project_arguments('-Xfreethreading_compatible=true', language : 'cython')
 else
-  message('Disabling freethreading')
+  message('Normal build (no freethreading and no limited API)')
 endif
 
 if get_option('coverage')

meson.options

@@ -1,3 +1,4 @@
 option('coverage', type : 'boolean', value : false, description : 'enable coverage build')
 option('add_flint_rpath', type : 'boolean', value : false)
 option('flint_version_check', type: 'boolean', value : true)
+option('limited_api_version', type: 'string', value : '3.12')

pyproject.toml

@@ -44,6 +44,10 @@ content-type = "text/markdown"
 requires = ["meson-python >= 0.18", "cython >=3.1,<3.2"]
 build-backend = "mesonpy"
 
+[tool.meson-python]
+
+limited-api = true
+
 [tool.cython-lint]
 # E129 visually indented line with same indent as next logical line
 # Reasoning: this rule is a little controversial

src/flint/flint_base/meson.build

@@ -23,5 +23,6 @@ foreach ext : exts
     dependencies: pyflint_deps,
     install: true,
     subdir: pkgdir,
+    limited_api: limited_api_version,
   )
 endforeach

src/flint/functions/meson.build

@@ -19,5 +19,6 @@ foreach ext : exts
     dependencies: pyflint_deps,
     install: true,
     subdir: 'flint/functions',
+    limited_api: limited_api_version,
   )
 endforeach

src/flint/meson.build

@@ -31,6 +31,7 @@ foreach ext : exts
     dependencies: pyflint_deps,
     install: true,
     subdir: thisdir,
+    limited_api: limited_api_version,
   )
 endforeach
 

src/flint/types/acb_poly.pyx

@@ -1,4 +1,4 @@
-from cpython.list cimport PyList_GET_SIZE
+from cpython.list cimport PyList_Size as PyList_GET_SIZE
 from flint.utils.typecheck cimport typecheck
 from flint.flint_base.flint_context cimport getprec
 from flint.flint_base.flint_base cimport flint_poly

src/flint/types/arb.pyx

@@ -1,4 +1,4 @@
-from cpython.float cimport PyFloat_AS_DOUBLE
+from cpython.float cimport PyFloat_AsDouble
 from cpython.long cimport PyLong_Check
 
 from flint.flint_base.flint_context cimport getprec
@@ -101,7 +101,7 @@ cdef int arb_set_python(arb_t x, obj, bint allow_conversion) except -1:
         return 1
 
     if typecheck(obj, float):
-        arf_set_d(arb_midref(x), PyFloat_AS_DOUBLE(obj))
+        arf_set_d(arb_midref(x), PyFloat_AsDouble(obj))
         mag_zero(arb_radref(x))
         return 1
 

src/flint/types/arb_poly.pyx

@@ -1,4 +1,4 @@
-from cpython.list cimport PyList_GET_SIZE
+from cpython.list cimport PyList_Size as PyList_GET_SIZE
 from flint.utils.typecheck cimport typecheck
 from flint.flint_base.flint_context cimport getprec
 from flint.flint_base.flint_base cimport flint_poly

src/flint/types/arf.pyx

@@ -1,4 +1,4 @@
-from cpython.float cimport PyFloat_AS_DOUBLE
+from cpython.float cimport PyFloat_AsDouble
 from flint.flint_base.flint_context cimport getprec
 from flint.flint_base.flint_context cimport thectx
 from flint.utils.typecheck cimport typecheck
@@ -44,7 +44,7 @@ cdef class arf:
             elif typecheck(val, arf):
                 arf_set(self.val, (<arf>val).val)
             elif typecheck(val, float):
-                arf_set_d(self.val, PyFloat_AS_DOUBLE(val))
+                arf_set_d(self.val, PyFloat_AsDouble(val))
             elif typecheck(val, tuple):
                 man = any_as_fmpz(val[0])
                 exp = any_as_fmpz(val[1])

src/flint/types/fmpq_poly.pyx

@@ -1,4 +1,4 @@
-from cpython.list cimport PyList_GET_SIZE
+from cpython.list cimport PyList_Size as PyList_GET_SIZE
 from flint.utils.typecheck cimport typecheck
 from flint.flint_base.flint_base cimport flint_poly
 from flint.types.fmpz_poly cimport any_as_fmpz_poly

src/flint/types/fmpz_mod_poly.pyx

@@ -1,4 +1,4 @@
-from cpython.list cimport PyList_GET_SIZE
+from cpython.list cimport PyList_Size as PyList_GET_SIZE
 
 from flint.pyflint cimport global_random_state
 from flint.flintlib.functions.fmpz_mod cimport fmpz_mod_neg, fmpz_mod_set_fmpz

src/flint/types/fmpz_poly.pyx

@@ -1,4 +1,4 @@
-from cpython.list cimport PyList_GET_SIZE
+from cpython.list cimport PyList_Size as PyList_GET_SIZE
 from cpython.long cimport PyLong_Check
 
 cimport libc.stdlib

src/flint/types/fq_default_poly.pyx

@@ -1,5 +1,5 @@
 cimport cython
-from cpython.list cimport PyList_GET_SIZE
+from cpython.list cimport PyList_Size as PyList_GET_SIZE
 from flint.flint_base.flint_base cimport flint_poly
 
 from flint.types.fmpz cimport fmpz, any_as_fmpz

src/flint/types/meson.build

@@ -111,5 +111,6 @@ foreach ext : exts
     dependencies: pyflint_deps,
     install: true,
     subdir: thisdir,
+    limited_api: limited_api_version,
   )
 endforeach

src/flint/types/nmod_poly.pyx

@@ -1,5 +1,5 @@
 cimport cython
-from cpython.list cimport PyList_GET_SIZE
+from cpython.list cimport PyList_Size as PyList_GET_SIZE
 from flint.flint_base.flint_base cimport flint_poly
 from flint.utils.typecheck cimport typecheck
 from flint.types.fmpz cimport fmpz, any_as_fmpz

src/flint/utils/meson.build

@@ -20,5 +20,6 @@ foreach ext : exts
     dependencies: pyflint_deps,
     install: true,
     subdir: thisdir,
+    limited_api: limited_api_version,
   )
 endforeach