gh-128911: Add tests on the PyImport C API

* Add Modules/_testlimitedcapi/import.c
* Add Lib/test/test_capi/test_import.py
* Remove _testcapi.check_pyimport_addmodule(): tests already covered
  by newly added tests.

Author: vstinner

Lib/test/test_capi/test_import.py

@@ -0,0 +1,125 @@
+import importlib.util
+import sys
+import types
+import unittest
+from test.support import import_helper
+from test.support.warnings_helper import check_warnings
+
+_testlimitedcapi = import_helper.import_module('_testlimitedcapi')
+
+
+class ImportTests(unittest.TestCase):
+    def test_getmagicnumber(self):
+        # Test PyImport_GetMagicNumber()
+        magic = _testlimitedcapi.PyImport_GetMagicNumber()
+        self.assertEqual(magic,
+                         int.from_bytes(importlib.util.MAGIC_NUMBER, 'little'))
+
+    def test_getmagictag(self):
+        # Test PyImport_GetMagicTag()
+        tag = _testlimitedcapi.PyImport_GetMagicTag()
+        self.assertEqual(tag, sys.implementation.cache_tag)
+
+    def test_getmoduledict(self):
+        # Test PyImport_GetModuleDict()
+        modules = _testlimitedcapi.PyImport_GetModuleDict()
+        self.assertIs(modules, sys.modules)
+
+    def check_import_loaded_module(self, import_module):
+        for name in ('os', 'sys', 'test', 'unittest'):
+            with self.subTest(name=name):
+                self.assertIn(name, sys.modules)
+                module = import_module(name)
+                self.assertIsInstance(module, types.ModuleType)
+                self.assertIs(module, sys.modules[name])
+
+    def check_import_fresh_module(self, import_module):
+        old_modules = dict(sys.modules)
+        try:
+            for name in ('asyncio', 'colorsys', 'datetime'):
+                with self.subTest(name=name):
+                    sys.modules.pop(name, None)
+                    module = import_module(name)
+                    self.assertIsInstance(module, types.ModuleType)
+                    self.assertIs(module, sys.modules[name])
+                    self.assertEqual(module.__name__, name)
+        finally:
+            sys.modules.clear()
+            sys.modules.update(old_modules)
+
+    def test_getmodule(self):
+        # Test PyImport_GetModule()
+        self.check_import_loaded_module(_testlimitedcapi.PyImport_GetModule)
+
+        nonexistent = 'nonexistent'
+        self.assertNotIn(nonexistent, sys.modules)
+        self.assertIsNone(_testlimitedcapi.PyImport_GetModule(nonexistent))
+        self.assertIsNone(_testlimitedcapi.PyImport_GetModule(''))
+        self.assertIsNone(_testlimitedcapi.PyImport_GetModule(object()))
+
+    def check_addmodule(self, add_module):
+        # create a new module
+        name = 'nonexistent'
+        self.assertNotIn(name, sys.modules)
+        try:
+            module = add_module(name)
+            self.assertIsInstance(module, types.ModuleType)
+            self.assertIs(module, sys.modules[name])
+        finally:
+            sys.modules.pop(name, None)
+
+        # get an existing module
+        self.check_import_loaded_module(add_module)
+
+    def test_addmoduleobject(self):
+        # Test PyImport_AddModuleObject()
+        self.check_addmodule(_testlimitedcapi.PyImport_AddModuleObject)
+
+    def test_addmodule(self):
+        # Test PyImport_AddModule()
+        self.check_addmodule(_testlimitedcapi.PyImport_AddModule)
+
+    def test_addmoduleref(self):
+        # Test PyImport_AddModuleRef()
+        self.check_addmodule(_testlimitedcapi.PyImport_AddModuleRef)
+
+    def check_import_func(self, import_module):
+        self.check_import_loaded_module(import_module)
+        self.check_import_fresh_module(import_module)
+
+        # Invalid module name types
+        with self.assertRaises(TypeError):
+            import_module(123)
+        with self.assertRaises(TypeError):
+            import_module(object())
+
+    def test_import(self):
+        # Test PyImport_Import()
+        self.check_import_func(_testlimitedcapi.PyImport_Import)
+
+    def test_importmodule(self):
+        # Test PyImport_ImportModule()
+        self.check_import_func(_testlimitedcapi.PyImport_ImportModule)
+
+    def test_importmodulenoblock(self):
+        # Test deprecated PyImport_ImportModuleNoBlock()
+        with check_warnings(('', DeprecationWarning)):
+            self.check_import_func(_testlimitedcapi.PyImport_ImportModuleNoBlock)
+
+    # TODO: test PyImport_ExecCodeModule()
+    # TODO: test PyImport_ExecCodeModuleEx()
+    # TODO: test PyImport_ExecCodeModuleWithPathnames()
+    # TODO: test PyImport_ExecCodeModuleObject()
+    # TODO: test PyImport_ImportModuleLevel()
+    # TODO: test PyImport_ImportModuleLevelObject()
+    # TODO: test PyImport_ImportModuleEx()
+    # TODO: test PyImport_GetImporter()
+    # TODO: test PyImport_ReloadModule()
+    # TODO: test PyImport_ImportFrozenModuleObject()
+    # TODO: test PyImport_ImportFrozenModule()
+    # TODO: test PyImport_AppendInittab()
+    # TODO: test PyImport_ExtendInittab()
+
+
+if __name__ == "__main__":
+    unittest.main()

Lib/test/test_import/__init__.py

@@ -3311,30 +3311,6 @@ def test_basic_multiple_interpreters_reset_each(self):
         #  * module's global state was initialized, not reset
 
 
-@cpython_only
-class CAPITests(unittest.TestCase):
-    def test_pyimport_addmodule(self):
-        # gh-105922: Test PyImport_AddModuleRef(), PyImport_AddModule()
-        # and PyImport_AddModuleObject()
-        _testcapi = import_module("_testcapi")
-        for name in (
-            'sys',     # frozen module
-            'test',    # package
-            __name__,  # package.module
-        ):
-            _testcapi.check_pyimport_addmodule(name)
-
-    def test_pyimport_addmodule_create(self):
-        # gh-105922: Test PyImport_AddModuleRef(), create a new module
-        _testcapi = import_module("_testcapi")
-        name = 'dontexist'
-        self.assertNotIn(name, sys.modules)
-        self.addCleanup(unload, name)
-
-        mod = _testcapi.check_pyimport_addmodule(name)
-        self.assertIs(mod, sys.modules[name])
-
-
 @cpython_only
 class TestMagicNumber(unittest.TestCase):
     def test_magic_number_endianness(self):

Modules/Setup.stdlib.in

@@ -163,7 +163,7 @@
 @MODULE__TESTBUFFER_TRUE@_testbuffer _testbuffer.c
 @MODULE__TESTINTERNALCAPI_TRUE@_testinternalcapi _testinternalcapi.c _testinternalcapi/test_lock.c _testinternalcapi/pytime.c _testinternalcapi/set.c _testinternalcapi/test_critical_sections.c
 @MODULE__TESTCAPI_TRUE@_testcapi _testcapimodule.c _testcapi/vectorcall.c _testcapi/heaptype.c _testcapi/abstract.c _testcapi/unicode.c _testcapi/dict.c _testcapi/set.c _testcapi/list.c _testcapi/tuple.c _testcapi/getargs.c _testcapi/datetime.c _testcapi/docstring.c _testcapi/mem.c _testcapi/watchers.c _testcapi/long.c _testcapi/float.c _testcapi/complex.c _testcapi/numbers.c _testcapi/structmember.c _testcapi/exceptions.c _testcapi/code.c _testcapi/buffer.c _testcapi/pyatomic.c _testcapi/run.c _testcapi/file.c _testcapi/codec.c _testcapi/immortal.c _testcapi/gc.c _testcapi/hash.c _testcapi/time.c _testcapi/bytes.c _testcapi/object.c _testcapi/monitoring.c  _testcapi/config.c
-@MODULE__TESTLIMITEDCAPI_TRUE@_testlimitedcapi _testlimitedcapi.c _testlimitedcapi/abstract.c _testlimitedcapi/bytearray.c _testlimitedcapi/bytes.c _testlimitedcapi/codec.c _testlimitedcapi/complex.c _testlimitedcapi/dict.c _testlimitedcapi/eval.c _testlimitedcapi/float.c _testlimitedcapi/heaptype_relative.c _testlimitedcapi/list.c _testlimitedcapi/long.c _testlimitedcapi/object.c _testlimitedcapi/pyos.c _testlimitedcapi/set.c _testlimitedcapi/sys.c _testlimitedcapi/tuple.c _testlimitedcapi/unicode.c _testlimitedcapi/vectorcall_limited.c _testlimitedcapi/version.c
+@MODULE__TESTLIMITEDCAPI_TRUE@_testlimitedcapi _testlimitedcapi.c _testlimitedcapi/abstract.c _testlimitedcapi/bytearray.c _testlimitedcapi/bytes.c _testlimitedcapi/codec.c _testlimitedcapi/complex.c _testlimitedcapi/dict.c _testlimitedcapi/eval.c _testlimitedcapi/float.c _testlimitedcapi/heaptype_relative.c _testlimitedcapi/import.c _testlimitedcapi/list.c _testlimitedcapi/long.c _testlimitedcapi/object.c _testlimitedcapi/pyos.c _testlimitedcapi/set.c _testlimitedcapi/sys.c _testlimitedcapi/tuple.c _testlimitedcapi/unicode.c _testlimitedcapi/vectorcall_limited.c _testlimitedcapi/version.c
 @MODULE__TESTCLINIC_TRUE@_testclinic _testclinic.c
 @MODULE__TESTCLINIC_LIMITED_TRUE@_testclinic_limited _testclinic_limited.c
 

Modules/_testcapimodule.c

@@ -3059,52 +3059,6 @@ function_set_closure(PyObject *self, PyObject *args)
     Py_RETURN_NONE;
 }
 
-static PyObject *
-check_pyimport_addmodule(PyObject *self, PyObject *args)
-{
-    const char *name;
-    if (!PyArg_ParseTuple(args, "s", &name)) {
-        return NULL;
-    }
-
-    // test PyImport_AddModuleRef()
-    PyObject *module = PyImport_AddModuleRef(name);
-    if (module == NULL) {
-        return NULL;
-    }
-    assert(PyModule_Check(module));
-    // module is a strong reference
-
-    // test PyImport_AddModule()
-    PyObject *module2 = PyImport_AddModule(name);
-    if (module2 == NULL) {
-        goto error;
-    }
-    assert(PyModule_Check(module2));
-    assert(module2 == module);
-    // module2 is a borrowed ref
-
-    // test PyImport_AddModuleObject()
-    PyObject *name_obj = PyUnicode_FromString(name);
-    if (name_obj == NULL) {
-        goto error;
-    }
-    PyObject *module3 = PyImport_AddModuleObject(name_obj);
-    Py_DECREF(name_obj);
-    if (module3 == NULL) {
-        goto error;
-    }
-    assert(PyModule_Check(module3));
-    assert(module3 == module);
-    // module3 is a borrowed ref
-
-    return module;
-
-error:
-    Py_DECREF(module);
-    return NULL;
-}
-
 
 static PyObject *
 test_weakref_capi(PyObject *Py_UNUSED(module), PyObject *Py_UNUSED(args))
@@ -3570,7 +3524,6 @@ static PyMethodDef TestMethods[] = {
     {"function_set_kw_defaults", function_set_kw_defaults, METH_VARARGS, NULL},
     {"function_get_closure", function_get_closure, METH_O, NULL},
     {"function_set_closure", function_set_closure, METH_VARARGS, NULL},
-    {"check_pyimport_addmodule", check_pyimport_addmodule, METH_VARARGS},
     {"test_weakref_capi", test_weakref_capi, METH_NOARGS},
     {"function_set_warning", function_set_warning, METH_NOARGS},
     {"test_critical_sections", test_critical_sections, METH_NOARGS},

Modules/_testlimitedcapi.c

@@ -56,6 +56,9 @@ PyInit__testlimitedcapi(void)
     if (_PyTestLimitedCAPI_Init_HeaptypeRelative(mod) < 0) {
         return NULL;
     }
+    if (_PyTestLimitedCAPI_Init_Import(mod) < 0) {
+        return NULL;
+    }
     if (_PyTestLimitedCAPI_Init_List(mod) < 0) {
         return NULL;
     }

Modules/_testlimitedcapi/import.c

@@ -0,0 +1,140 @@
+// Need limited C API version 3.7 for PyImport_GetModule()
+#include "pyconfig.h"   // Py_GIL_DISABLED
+#if !defined(Py_GIL_DISABLED) && !defined(Py_LIMITED_API)
+#  define Py_LIMITED_API 0x030d0000
+#endif
+
+#include "parts.h"
+#include "util.h"
+
+
+/* Test PyImport_GetMagicNumber() */
+static PyObject *
+pyimport_getmagicnumber(PyObject *Py_UNUSED(module), PyObject *Py_UNUSED(args))
+{
+    long magic = PyImport_GetMagicNumber();
+    return PyLong_FromLong(magic);
+}
+
+
+/* Test PyImport_GetMagicTag() */
+static PyObject *
+pyimport_getmagictag(PyObject *Py_UNUSED(module), PyObject *Py_UNUSED(args))
+{
+    const char *tag = PyImport_GetMagicTag();
+    return PyUnicode_FromString(tag);
+}
+
+
+/* Test PyImport_GetModuleDict() */
+static PyObject *
+pyimport_getmoduledict(PyObject *Py_UNUSED(module), PyObject *Py_UNUSED(args))
+{
+    return Py_XNewRef(PyImport_GetModuleDict());
+}
+
+
+/* Test PyImport_GetModule() */
+static PyObject *
+pyimport_getmodule(PyObject *Py_UNUSED(module), PyObject *name)
+{
+    assert(!PyErr_Occurred());
+    PyObject *module = PyImport_GetModule(name);
+    if (module == NULL && !PyErr_Occurred()) {
+        Py_RETURN_NONE;
+    }
+    return module;
+}
+
+
+/* Test PyImport_AddModuleObject() */
+static PyObject *
+pyimport_addmoduleobject(PyObject *Py_UNUSED(module), PyObject *name)
+{
+    return Py_XNewRef(PyImport_AddModuleObject(name));
+}
+
+
+/* Test PyImport_AddModule() */
+static PyObject *
+pyimport_addmodule(PyObject *Py_UNUSED(module), PyObject *args)
+{
+    const char *name;
+    if (!PyArg_ParseTuple(args, "s", &name)) {
+        return NULL;
+    }
+
+    return Py_XNewRef(PyImport_AddModule(name));
+}
+
+
+/* Test PyImport_AddModuleRef() */
+static PyObject *
+pyimport_addmoduleref(PyObject *Py_UNUSED(module), PyObject *args)
+{
+    const char *name;
+    if (!PyArg_ParseTuple(args, "s", &name)) {
+        return NULL;
+    }
+
+    return PyImport_AddModuleRef(name);
+}
+
+
+/* Test PyImport_Import() */
+static PyObject *
+pyimport_import(PyObject *Py_UNUSED(module), PyObject *name)
+{
+    return PyImport_Import(name);
+}
+
+
+/* Test PyImport_ImportModule() */
+static PyObject *
+pyimport_importmodule(PyObject *Py_UNUSED(module), PyObject *args)
+{
+    const char *name;
+    if (!PyArg_ParseTuple(args, "s", &name)) {
+        return NULL;
+    }
+
+    return PyImport_ImportModule(name);
+}
+
+
+/* Test PyImport_ImportModuleNoBlock() */
+static PyObject *
+pyimport_importmodulenoblock(PyObject *Py_UNUSED(module), PyObject *args)
+{
+    const char *name;
+    if (!PyArg_ParseTuple(args, "s", &name)) {
+        return NULL;
+    }
+
+    _Py_COMP_DIAG_PUSH
+    _Py_COMP_DIAG_IGNORE_DEPR_DECLS
+    return PyImport_ImportModuleNoBlock(name);
+    _Py_COMP_DIAG_POP
+}
+
+
+static PyMethodDef test_methods[] = {
+    {"PyImport_GetMagicNumber", pyimport_getmagicnumber, METH_NOARGS},
+    {"PyImport_GetMagicTag", pyimport_getmagictag, METH_NOARGS},
+    {"PyImport_GetModuleDict", pyimport_getmoduledict, METH_NOARGS},
+    {"PyImport_GetModule", pyimport_getmodule, METH_O},
+    {"PyImport_AddModuleObject", pyimport_addmoduleobject, METH_O},
+    {"PyImport_AddModule", pyimport_addmodule, METH_VARARGS},
+    {"PyImport_AddModuleRef", pyimport_addmoduleref, METH_VARARGS},
+    {"PyImport_Import", pyimport_import, METH_O},
+    {"PyImport_ImportModule", pyimport_importmodule, METH_VARARGS},
+    {"PyImport_ImportModuleNoBlock", pyimport_importmodulenoblock, METH_VARARGS},
+    {NULL},
+};
+
+
+int
+_PyTestLimitedCAPI_Init_Import(PyObject *module)
+{
+    return PyModule_AddFunctions(module, test_methods);
+}

Modules/_testlimitedcapi/parts.h

@@ -31,6 +31,7 @@ int _PyTestLimitedCAPI_Init_Dict(PyObject *module);
 int _PyTestLimitedCAPI_Init_Eval(PyObject *module);
 int _PyTestLimitedCAPI_Init_Float(PyObject *module);
 int _PyTestLimitedCAPI_Init_HeaptypeRelative(PyObject *module);
+int _PyTestLimitedCAPI_Init_Import(PyObject *module);
 int _PyTestLimitedCAPI_Init_Object(PyObject *module);
 int _PyTestLimitedCAPI_Init_List(PyObject *module);
 int _PyTestLimitedCAPI_Init_Long(PyObject *module);