bpo-42639: Cleanup atexitmodule.c (GH-23770)

* Rename "atexitmodule_state" to "struct atexit_state".
* Rename "modstate" to "state".
* Rename "self" parameter to "module".
* test_atexit uses textwrap.dedent().
* Remove _Py_PyAtExit() function: inline it into atexit_exec().
* PyInterpreterState: rename pyexitfunc to atexit_func, rename
  pyexitmodule to atexit_module.

Author: vstinner

Include/cpython/pylifecycle.h

@@ -35,11 +35,6 @@ PyAPI_FUNC(int) Py_RunMain(void);
 
 PyAPI_FUNC(void) _Py_NO_RETURN Py_ExitStatusException(PyStatus err);
 
-/* Py_PyAtExit is for the atexit module, Py_AtExit is for low-level
- * exit functions.
- */
-PyAPI_FUNC(void) _Py_PyAtExit(void (*func)(PyObject *), PyObject *);
-
 /* Restore signals that the interpreter has called SIG_IGN on to SIG_DFL. */
 PyAPI_FUNC(void) _Py_RestoreSignals(void);
 

Include/internal/pycore_interp.h

@@ -234,8 +234,8 @@ struct _is {
     PyObject *after_forkers_child;
 #endif
     /* AtExit module */
-    void (*pyexitfunc)(PyObject *);
-    PyObject *pyexitmodule;
+    void (*atexit_func)(PyObject *);
+    PyObject *atexit_module;
 
     uint64_t tstate_next_unique_id;
 

Lib/test/test_atexit.py

@@ -1,8 +1,9 @@
-import sys
-import unittest
-import io
 import atexit
+import io
 import os
+import sys
+import textwrap
+import unittest
 from test import support
 from test.support import script_helper
 
@@ -156,15 +157,15 @@ def test_bound_methods(self):
 
     def test_shutdown(self):
         # Actually test the shutdown mechanism in a subprocess
-        code = """if 1:
+        code = textwrap.dedent("""
             import atexit
 
             def f(msg):
                 print(msg)
 
             atexit.register(f, "one")
             atexit.register(f, "two")
-            """
+        """)
         res = script_helper.assert_python_ok("-c", code)
         self.assertEqual(res.out.decode().splitlines(), ["two", "one"])
         self.assertFalse(res.err)
@@ -178,13 +179,13 @@ def test_callbacks_leak(self):
         # take care to free callbacks in its per-subinterpreter module
         # state.
         n = atexit._ncallbacks()
-        code = r"""if 1:
+        code = textwrap.dedent(r"""
             import atexit
             def f():
                 pass
             atexit.register(f)
             del atexit
-            """
+        """)
         ret = support.run_in_subinterp(code)
         self.assertEqual(ret, 0)
         self.assertEqual(atexit._ncallbacks(), n)
@@ -193,13 +194,13 @@ def test_callbacks_leak_refcycle(self):
         # Similar to the above, but with a refcycle through the atexit
         # module.
         n = atexit._ncallbacks()
-        code = r"""if 1:
+        code = textwrap.dedent(r"""
             import atexit
             def f():
                 pass
             atexit.register(f)
             atexit.__atexit = atexit
-            """
+        """)
         ret = support.run_in_subinterp(code)
         self.assertEqual(ret, 0)
         self.assertEqual(atexit._ncallbacks(), n)
@@ -210,13 +211,13 @@ def test_callback_on_subinterpreter_teardown(self):
         expected = b"The test has passed!"
         r, w = os.pipe()
 
-        code = r"""if 1:
+        code = textwrap.dedent(r"""
             import os
             import atexit
             def callback():
                 os.write({:d}, b"The test has passed!")
             atexit.register(callback)
-        """.format(w)
+        """.format(w))
         ret = support.run_in_subinterp(code)
         os.close(w)
         self.assertEqual(os.read(r, len(expected)), expected)