python · vstinner · Dec 13, 2024 · Dec 13, 2024
diff --git a/Lib/test/test_cppext/__init__.py b/Lib/test/test_cppext/__init__.py
@@ -41,12 +41,17 @@ def test_build_cpp11(self):
    def test_build_cpp14(self):
        self.check_build('_testcpp14ext', std='c++14')

-    def check_build(self, extension_name, std=None):
+    @support.requires_gil_enabled('incompatible with Free Threading')
+    def test_build_limited(self):
+        self.check_build('_testcppext_limited', limited=True)
+
+    def check_build(self, extension_name, std=None, limited=False):
        venv_dir = 'env'
        with support.setup_venv_with_pip_setuptools_wheel(venv_dir) as python_exe:
-            self._check_build(extension_name, python_exe, std=std)
+            self._check_build(extension_name, python_exe,
+                              std=std, limited=limited)

-    def _check_build(self, extension_name, python_exe, std):
+    def _check_build(self, extension_name, python_exe, std, limited):
        pkg_dir = 'pkg'
        os.mkdir(pkg_dir)
        shutil.copy(SETUP, os.path.join(pkg_dir, os.path.basename(SETUP)))
@@ -56,6 +61,8 @@ def run_cmd(operation, cmd):
            env = os.environ.copy()
            if std:
                env['CPYTHON_TEST_CPP_STD'] = std
+            if limited:
+                env['CPYTHON_TEST_LIMITED'] = '1'
            env['CPYTHON_TEST_EXT_NAME'] = extension_name
            if support.verbose:
                print('Run:', ' '.join(map(shlex.quote, cmd)))

diff --git a/Lib/test/test_cppext/extension.cpp b/Lib/test/test_cppext/extension.cpp
@@ -62,6 +62,7 @@ test_api_casts(PyObject *Py_UNUSED(module), PyObject *Py_UNUSED(args))
    Py_ssize_t refcnt = Py_REFCNT(obj);
    assert(refcnt >= 1);

+#ifndef Py_LIMITED_API
    // gh-92138: For backward compatibility, functions of Python C API accepts
    // "const PyObject*". Check that using it does not emit C++ compiler
    // warnings.
@@ -74,6 +75,7 @@ test_api_casts(PyObject *Py_UNUSED(module), PyObject *Py_UNUSED(args))
    assert(PyTuple_GET_SIZE(const_obj) == 2);
    PyObject *one = PyTuple_GET_ITEM(const_obj, 0);
    assert(PyLong_AsLong(one) == 1);
+#endif

    // gh-92898: StrongRef doesn't inherit from PyObject but has an operator to
    // cast to PyObject*.
@@ -106,6 +108,12 @@ test_unicode(PyObject *Py_UNUSED(module), PyObject *Py_UNUSED(args))
    }

    assert(PyUnicode_Check(str));
+
+    assert(PyUnicode_GetLength(str) == 3);
+    assert(PyUnicode_ReadChar(str, 0) == 'a');
+    assert(PyUnicode_ReadChar(str, 1) == 'b');
+
+#ifndef Py_LIMITED_API
    assert(PyUnicode_GET_LENGTH(str) == 3);

    // gh-92800: test PyUnicode_READ()
@@ -121,6 +129,7 @@ test_unicode(PyObject *Py_UNUSED(module), PyObject *Py_UNUSED(args))
    assert(PyUnicode_READ(ukind, const_data, 2) == 'c');

    assert(PyUnicode_READ_CHAR(str, 1) == 'b');
+#endif

    Py_DECREF(str);
    Py_RETURN_NONE;

diff --git a/Lib/test/test_cppext/setup.py b/Lib/test/test_cppext/setup.py
@@ -33,6 +33,7 @@ def main():
    cppflags = list(CPPFLAGS)
    std = os.environ.get("CPYTHON_TEST_CPP_STD", "")
    module_name = os.environ["CPYTHON_TEST_EXT_NAME"]
+    limited = bool(os.environ.get("CPYTHON_TEST_LIMITED", ""))

    cppflags = list(CPPFLAGS)
    cppflags.append(f'-DMODULE_NAME={module_name}')
@@ -59,6 +60,11 @@ def main():
        # CC env var overrides sysconfig CC variable in setuptools
        os.environ['CC'] = cmd

+    # Define Py_LIMITED_API macro
+    if limited:
+        version = sys.hexversion
+        cppflags.append(f'-DPy_LIMITED_API={version:#x}')
+
    # On Windows, add PCbuild\amd64\ to include and library directories
    include_dirs = []
    library_dirs = []

diff --git a/Misc/NEWS.d/next/Tests/2024-12-13-13-41-34.gh-issue-127906.NuRHlB.rst b/Misc/NEWS.d/next/Tests/2024-12-13-13-41-34.gh-issue-127906.NuRHlB.rst
@@ -0,0 +1 @@
+Test the limited C API in test_cppext. Patch by Victor Stinner.
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1 @@
		Test the limited C API in test_cppext. Patch by Victor Stinner.