Issue #26900: Excluded underscored names and other private API from limited API.

21 files changed, 74 insertions, 15 deletions

diff --git a/Doc/whatsnew/3.5.rst b/Doc/whatsnew/3.5.rst
index 9b71f66..246d9c5 100644
--- a/Doc/whatsnew/3.5.rst
+++ b/Doc/whatsnew/3.5.rst
@@ -2176,8 +2176,7 @@ New ``calloc`` functions were added:
 
 * :c:func:`PyMem_RawCalloc`,
 * :c:func:`PyMem_Calloc`,
-* :c:func:`PyObject_Calloc`,
-* :c:func:`_PyObject_GC_Calloc`.
+* :c:func:`PyObject_Calloc`.
 
 (Contributed by Victor Stinner in :issue:`21233`.)
 
diff --git a/Include/abstract.h b/Include/abstract.h
index 3e630b1..8748367 100644
--- a/Include/abstract.h
+++ b/Include/abstract.h
@@ -7,7 +7,9 @@ extern "C" {
 #ifdef PY_SSIZE_T_CLEAN
 #define PyObject_CallFunction _PyObject_CallFunction_SizeT
 #define PyObject_CallMethod _PyObject_CallMethod_SizeT
+#ifndef Py_LIMITED_API
 #define _PyObject_CallMethodId _PyObject_CallMethodId_SizeT
+#endif /* !Py_LIMITED_API */
 #endif
 
 /* Abstract Object Interface (many thanks to Jim Fulton) */
@@ -385,6 +387,7 @@ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx*/
      Python expression: o.method(args).
        */
 
+#ifndef Py_LIMITED_API
      PyAPI_FUNC(PyObject *) _PyObject_CallMethodId(PyObject *o,
                                                    _Py_Identifier *method,
                                                    const char *format, ...);
@@ -393,6 +396,7 @@ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx*/
          Like PyObject_CallMethod, but expect a _Py_Identifier* as the
          method name.
        */
+#endif /* !Py_LIMITED_API */
 
      PyAPI_FUNC(PyObject *) _PyObject_CallFunction_SizeT(PyObject *callable,
                                                          const char *format,
@@ -401,10 +405,12 @@ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx*/
                                                        const char *name,
                                                        const char *format,
                                                        ...);
+#ifndef Py_LIMITED_API
      PyAPI_FUNC(PyObject *) _PyObject_CallMethodId_SizeT(PyObject *o,
                                                        _Py_Identifier *name,
                                                        const char *format,
                                                        ...);
+#endif /* !Py_LIMITED_API */
 
      PyAPI_FUNC(PyObject *) PyObject_CallFunctionObjArgs(PyObject *callable,
                                                          ...);
@@ -420,9 +426,11 @@ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx*/
 
      PyAPI_FUNC(PyObject *) PyObject_CallMethodObjArgs(PyObject *o,
                                                        PyObject *method, ...);
+#ifndef Py_LIMITED_API
      PyAPI_FUNC(PyObject *) _PyObject_CallMethodIdObjArgs(PyObject *o,
                                                struct _Py_Identifier *method,
                                                ...);
+#endif /* !Py_LIMITED_API */
 
        /*
      Call the method named m of object o with a variable number of
@@ -1340,13 +1348,13 @@ PyAPI_FUNC(int) _PyObject_RealIsSubclass(PyObject *derived, PyObject *cls);
 PyAPI_FUNC(char *const *) _PySequence_BytesToCharpArray(PyObject* self);
 
 PyAPI_FUNC(void) _Py_FreeCharPArray(char *const array[]);
-#endif
 
 /* For internal use by buffer API functions */
 PyAPI_FUNC(void) _Py_add_one_to_index_F(int nd, Py_ssize_t *index,
                                         const Py_ssize_t *shape);
 PyAPI_FUNC(void) _Py_add_one_to_index_C(int nd, Py_ssize_t *index,
                                         const Py_ssize_t *shape);
+#endif /* !Py_LIMITED_API */
 
 
 #ifdef __cplusplus
diff --git a/Include/ceval.h b/Include/ceval.h
index c682063..89c6062 100644
--- a/Include/ceval.h
+++ b/Include/ceval.h
@@ -179,7 +179,9 @@ PyAPI_FUNC(void) PyEval_RestoreThread(PyThreadState *);
 
 PyAPI_FUNC(int)  PyEval_ThreadsInitialized(void);
 PyAPI_FUNC(void) PyEval_InitThreads(void);
+#ifndef Py_LIMITED_API
 PyAPI_FUNC(void) _PyEval_FiniThreads(void);
+#endif /* !Py_LIMITED_API */
 PyAPI_FUNC(void) PyEval_AcquireLock(void);
 PyAPI_FUNC(void) PyEval_ReleaseLock(void);
 PyAPI_FUNC(void) PyEval_AcquireThread(PyThreadState *tstate);
diff --git a/Include/descrobject.h b/Include/descrobject.h
index e2ba97f..8f3e84c 100644
--- a/Include/descrobject.h
+++ b/Include/descrobject.h
@@ -78,7 +78,9 @@ PyAPI_DATA(PyTypeObject) PyMemberDescr_Type;
 PyAPI_DATA(PyTypeObject) PyMethodDescr_Type;
 PyAPI_DATA(PyTypeObject) PyWrapperDescr_Type;
 PyAPI_DATA(PyTypeObject) PyDictProxy_Type;
+#ifndef Py_LIMITED_API
 PyAPI_DATA(PyTypeObject) _PyMethodWrapper_Type;
+#endif /* Py_LIMITED_API */
 
 PyAPI_FUNC(PyObject *) PyDescr_NewMethod(PyTypeObject *, PyMethodDef *);
 PyAPI_FUNC(PyObject *) PyDescr_NewClassMethod(PyTypeObject *, PyMethodDef *);
diff --git a/Include/dictobject.h b/Include/dictobject.h
index 19194ed..931d4bf 100644
--- a/Include/dictobject.h
+++ b/Include/dictobject.h
@@ -73,9 +73,9 @@ PyAPI_FUNC(PyObject *) _PyDict_GetItem_KnownHash(PyObject *mp, PyObject *key,
                                        Py_hash_t hash);
 #endif
 PyAPI_FUNC(PyObject *) PyDict_GetItemWithError(PyObject *mp, PyObject *key);
+#ifndef Py_LIMITED_API
 PyAPI_FUNC(PyObject *) _PyDict_GetItemIdWithError(PyObject *dp,
                                                   struct _Py_Identifier *key);
-#ifndef Py_LIMITED_API
 PyAPI_FUNC(PyObject *) PyDict_SetDefault(
     PyObject *mp, PyObject *key, PyObject *defaultobj);
 #endif
@@ -145,9 +145,13 @@ PyAPI_FUNC(int) PyDict_MergeFromSeq2(PyObject *d,
                                            int override);
 
 PyAPI_FUNC(PyObject *) PyDict_GetItemString(PyObject *dp, const char *key);
+#ifndef Py_LIMITED_API
 PyAPI_FUNC(PyObject *) _PyDict_GetItemId(PyObject *dp, struct _Py_Identifier *key);
+#endif /* !Py_LIMITED_API */
 PyAPI_FUNC(int) PyDict_SetItemString(PyObject *dp, const char *key, PyObject *item);
+#ifndef Py_LIMITED_API
 PyAPI_FUNC(int) _PyDict_SetItemId(PyObject *dp, struct _Py_Identifier *key, PyObject *item);
+#endif /* !Py_LIMITED_API */
 PyAPI_FUNC(int) PyDict_DelItemString(PyObject *dp, const char *key);
 
 #ifndef Py_LIMITED_API
diff --git a/Include/fileutils.h b/Include/fileutils.h
index 63ff80e..4016431 100644
--- a/Include/fileutils.h
+++ b/Include/fileutils.h
@@ -5,8 +5,6 @@
 extern "C" {
 #endif
 
-PyAPI_FUNC(PyObject *) _Py_device_encoding(int);
-
 PyAPI_FUNC(wchar_t *) Py_DecodeLocale(
     const char *arg,
     size_t *size);
@@ -17,6 +15,8 @@ PyAPI_FUNC(char*) Py_EncodeLocale(
 
 #ifndef Py_LIMITED_API
 
+PyAPI_FUNC(PyObject *) _Py_device_encoding(int);
+
 #ifdef MS_WINDOWS
 struct _Py_stat_struct {
     unsigned long st_dev;
@@ -46,13 +46,11 @@ PyAPI_FUNC(int) _Py_fstat(
 PyAPI_FUNC(int) _Py_fstat_noraise(
     int fd,
     struct _Py_stat_struct *status);
-#endif   /* Py_LIMITED_API */
 
 PyAPI_FUNC(int) _Py_stat(
     PyObject *path,
     struct stat *status);
 
-#ifndef Py_LIMITED_API
 PyAPI_FUNC(int) _Py_open(
     const char *pathname,
     int flags);
@@ -60,7 +58,6 @@ PyAPI_FUNC(int) _Py_open(
 PyAPI_FUNC(int) _Py_open_noraise(
     const char *pathname,
     int flags);
-#endif
 
 PyAPI_FUNC(FILE *) _Py_wfopen(
     const wchar_t *path,
@@ -107,7 +104,6 @@ PyAPI_FUNC(wchar_t*) _Py_wgetcwd(
     wchar_t *buf,
     size_t size);
 
-#ifndef Py_LIMITED_API
 PyAPI_FUNC(int) _Py_get_inheritable(int fd);
 
 PyAPI_FUNC(int) _Py_set_inheritable(int fd, int inheritable,
diff --git a/Include/import.h b/Include/import.h
index afdfac2..46c0d8e 100644
--- a/Include/import.h
+++ b/Include/import.h
@@ -7,7 +7,9 @@
 extern "C" {
 #endif
 
+#ifndef Py_LIMITED_API
 PyAPI_FUNC(void) _PyImportZip_Init(void);
+#endif /* !Py_LIMITED_API */
 
 PyMODINIT_FUNC PyInit_imp(void);
 PyAPI_FUNC(long) PyImport_GetMagicNumber(void);
diff --git a/Include/intrcheck.h b/Include/intrcheck.h
index f53fee1..8fb96cf 100644
--- a/Include/intrcheck.h
+++ b/Include/intrcheck.h
@@ -8,12 +8,15 @@ extern "C" {
 PyAPI_FUNC(int) PyOS_InterruptOccurred(void);
 PyAPI_FUNC(void) PyOS_InitInterrupts(void);
 PyAPI_FUNC(void) PyOS_AfterFork(void);
+
+#ifndef Py_LIMITED_API
 PyAPI_FUNC(int) _PyOS_IsMainThread(void);
 
 #ifdef MS_WINDOWS
 /* windows.h is not included by Python.h so use void* instead of HANDLE */
 PyAPI_FUNC(void*) _PyOS_SigintEvent(void);
 #endif
+#endif /* !Py_LIMITED_API */
 
 #ifdef __cplusplus
 }
diff --git a/Include/longobject.h b/Include/longobject.h
index 2957f16..efd409c 100644
--- a/Include/longobject.h
+++ b/Include/longobject.h
@@ -204,8 +204,10 @@ PyAPI_FUNC(int) _PyLong_FormatAdvancedWriter(
 PyAPI_FUNC(unsigned long) PyOS_strtoul(const char *, char **, int);
 PyAPI_FUNC(long) PyOS_strtol(const char *, char **, int);
 
+#ifndef Py_LIMITED_API
 /* For use by the gcd function in mathmodule.c */
 PyAPI_FUNC(PyObject *) _PyLong_GCD(PyObject *, PyObject *);
+#endif /* !Py_LIMITED_API */
 
 #ifdef __cplusplus
 }
diff --git a/Include/modsupport.h b/Include/modsupport.h
index 99581a3..833e33d 100644
--- a/Include/modsupport.h
+++ b/Include/modsupport.h
@@ -15,12 +15,16 @@ extern "C" {
 #define PyArg_Parse                     _PyArg_Parse_SizeT
 #define PyArg_ParseTuple                _PyArg_ParseTuple_SizeT
 #define PyArg_ParseTupleAndKeywords     _PyArg_ParseTupleAndKeywords_SizeT
+#ifndef Py_LIMITED_API
 #define PyArg_VaParse                   _PyArg_VaParse_SizeT
 #define PyArg_VaParseTupleAndKeywords   _PyArg_VaParseTupleAndKeywords_SizeT
+#endif /* !Py_LIMITED_API */
 #define Py_BuildValue                   _Py_BuildValue_SizeT
 #define Py_VaBuildValue                 _Py_VaBuildValue_SizeT
 #else
+#ifndef Py_LIMITED_API
 PyAPI_FUNC(PyObject *) _Py_VaBuildValue_SizeT(const char *, va_list);
+#endif /* !Py_LIMITED_API */
 #endif
 
 /* Due to a glitch in 3.2, the _SizeT versions weren't exported from the DLL. */
diff --git a/Include/namespaceobject.h b/Include/namespaceobject.h
index a412f05..0c8d95c 100644
--- a/Include/namespaceobject.h
+++ b/Include/namespaceobject.h
@@ -7,9 +7,11 @@
 extern "C" {
 #endif
 
+#ifndef Py_LIMITED_API
 PyAPI_DATA(PyTypeObject) _PyNamespace_Type;
 
 PyAPI_FUNC(PyObject *) _PyNamespace_New(PyObject *kwds);
+#endif /* !Py_LIMITED_API */
 
 #ifdef __cplusplus
 }
diff --git a/Include/object.h b/Include/object.h
index 5b4ef98..338ec1b 100644
--- a/Include/object.h
+++ b/Include/object.h
@@ -118,6 +118,7 @@ typedef struct {
 #define Py_TYPE(ob)             (((PyObject*)(ob))->ob_type)
 #define Py_SIZE(ob)             (((PyVarObject*)(ob))->ob_size)
 
+#ifndef Py_LIMITED_API
 /********************* String Literals ****************************************/
 /* This structure helps managing static strings. The basic usage goes like this:
    Instead of doing
@@ -148,6 +149,8 @@ typedef struct _Py_Identifier {
 #define _Py_static_string(varname, value)  static _Py_Identifier varname = _Py_static_string_init(value)
 #define _Py_IDENTIFIER(varname) _Py_static_string(PyId_##varname, #varname)
 
+#endif /* !Py_LIMITED_API */
+
 /*
 Type objects contain a string containing the type name (to help somewhat
 in debugging), the allocation parameters (see PyObject_New() and
@@ -512,8 +515,8 @@ PyAPI_FUNC(PyObject *) _PyType_GetTextSignatureFromInternalDoc(const char *, con
 #endif
 
 /* Generic operations on objects */
-struct _Py_Identifier;
 #ifndef Py_LIMITED_API
+struct _Py_Identifier;
 PyAPI_FUNC(int) PyObject_Print(PyObject *, FILE *, int);
 PyAPI_FUNC(void) _Py_BreakPoint(void);
 PyAPI_FUNC(void) _PyObject_Dump(PyObject *);
@@ -530,11 +533,11 @@ PyAPI_FUNC(int) PyObject_HasAttrString(PyObject *, const char *);
 PyAPI_FUNC(PyObject *) PyObject_GetAttr(PyObject *, PyObject *);
 PyAPI_FUNC(int) PyObject_SetAttr(PyObject *, PyObject *, PyObject *);
 PyAPI_FUNC(int) PyObject_HasAttr(PyObject *, PyObject *);
+#ifndef Py_LIMITED_API
 PyAPI_FUNC(int) _PyObject_IsAbstract(PyObject *);
 PyAPI_FUNC(PyObject *) _PyObject_GetAttrId(PyObject *, struct _Py_Identifier *);
 PyAPI_FUNC(int) _PyObject_SetAttrId(PyObject *, struct _Py_Identifier *, PyObject *);
 PyAPI_FUNC(int) _PyObject_HasAttrId(PyObject *, struct _Py_Identifier *);
-#ifndef Py_LIMITED_API
 PyAPI_FUNC(PyObject **) _PyObject_GetDictPtr(PyObject *);
 #endif
 PyAPI_FUNC(PyObject *) PyObject_SelfIter(PyObject *);
@@ -557,6 +560,7 @@ PyAPI_FUNC(void) PyObject_CallFinalizer(PyObject *);
 PyAPI_FUNC(int) PyObject_CallFinalizerFromDealloc(PyObject *);
 #endif
 
+#ifndef Py_LIMITED_API
 /* Same as PyObject_Generic{Get,Set}Attr, but passing the attributes
    dict as the last parameter. */
 PyAPI_FUNC(PyObject *)
@@ -564,6 +568,7 @@ _PyObject_GenericGetAttrWithDict(PyObject *, PyObject *, PyObject *);
 PyAPI_FUNC(int)
 _PyObject_GenericSetAttrWithDict(PyObject *, PyObject *,
                                  PyObject *, PyObject *);
+#endif /* !Py_LIMITED_API */
 
 /* Helper to look up a builtin object */
 #ifndef Py_LIMITED_API
@@ -888,8 +893,10 @@ they can have object code that is not dependent on Python compilation flags.
 PyAPI_FUNC(void) Py_IncRef(PyObject *);
 PyAPI_FUNC(void) Py_DecRef(PyObject *);
 
+#ifndef Py_LIMITED_API
 PyAPI_DATA(PyTypeObject) _PyNone_Type;
 PyAPI_DATA(PyTypeObject) _PyNotImplemented_Type;
+#endif /* !Py_LIMITED_API */
 
 /*
 _Py_NoneStruct is an object of undefined type which can be used in contexts
@@ -922,10 +929,12 @@ PyAPI_DATA(PyObject) _Py_NotImplementedStruct; /* Don't use this directly */
 #define Py_GT 4
 #define Py_GE 5
 
+#ifndef Py_LIMITED_API
 /* Maps Py_LT to Py_GT, ..., Py_GE to Py_LE.
  * Defined in object.c.
  */
 PyAPI_DATA(int) _Py_SwappedOp[];
+#endif /* !Py_LIMITED_API */
 
 
 /*
@@ -1022,12 +1031,14 @@ chain of N deallocations is broken into N / PyTrash_UNWIND_LEVEL pieces,
 with the call stack never exceeding a depth of PyTrash_UNWIND_LEVEL.
 */
 
+#ifndef Py_LIMITED_API
 /* This is the old private API, invoked by the macros before 3.2.4.
    Kept for binary compatibility of extensions using the stable ABI. */
 PyAPI_FUNC(void) _PyTrash_deposit_object(PyObject*);
 PyAPI_FUNC(void) _PyTrash_destroy_chain(void);
 PyAPI_DATA(int) _PyTrash_delete_nesting;
 PyAPI_DATA(PyObject *) _PyTrash_delete_later;
+#endif /* !Py_LIMITED_API */
 
 /* The new thread-safe private API, invoked by the macros below. */
 PyAPI_FUNC(void) _PyTrash_thread_deposit_object(PyObject*);
diff --git a/Include/objimpl.h b/Include/objimpl.h
index 519ae51..c0ed9b7 100644
--- a/Include/objimpl.h
+++ b/Include/objimpl.h
@@ -99,8 +99,10 @@ PyAPI_FUNC(void *) PyObject_Calloc(size_t nelem, size_t elsize);
 PyAPI_FUNC(void *) PyObject_Realloc(void *ptr, size_t new_size);
 PyAPI_FUNC(void) PyObject_Free(void *ptr);
 
+#ifndef Py_LIMITED_API
 /* This function returns the number of allocated memory blocks, regardless of size */
 PyAPI_FUNC(Py_ssize_t) _Py_GetAllocatedBlocks(void);
+#endif /* !Py_LIMITED_API */
 
 /* Macros */
 #ifdef WITH_PYMALLOC
@@ -323,8 +325,10 @@ extern PyGC_Head *_PyGC_generation0;
         (!PyTuple_CheckExact(obj) || _PyObject_GC_IS_TRACKED(obj)))
 #endif /* Py_LIMITED_API */
 
+#ifndef Py_LIMITED_API
 PyAPI_FUNC(PyObject *) _PyObject_GC_Malloc(size_t size);
 PyAPI_FUNC(PyObject *) _PyObject_GC_Calloc(size_t size);
+#endif /* !Py_LIMITED_API */
 PyAPI_FUNC(PyObject *) _PyObject_GC_New(PyTypeObject *);
 PyAPI_FUNC(PyVarObject *) _PyObject_GC_NewVar(PyTypeObject *, Py_ssize_t);
 PyAPI_FUNC(void) PyObject_GC_Track(void *);
diff --git a/Include/pygetopt.h b/Include/pygetopt.h
index 425c7dd..962720c 100644
--- a/Include/pygetopt.h
+++ b/Include/pygetopt.h
@@ -11,9 +11,9 @@ PyAPI_DATA(int) _PyOS_optind;
 PyAPI_DATA(wchar_t *) _PyOS_optarg;
 
 PyAPI_FUNC(void) _PyOS_ResetGetOpt(void);
-#endif
 
 PyAPI_FUNC(int) _PyOS_GetOpt(int argc, wchar_t **argv, wchar_t *optstring);
+#endif /* !Py_LIMITED_API */
 
 #ifdef __cplusplus
 }
diff --git a/Include/pylifecycle.h b/Include/pylifecycle.h
index 8390467..5a67666 100644
--- a/Include/pylifecycle.h
+++ b/Include/pylifecycle.h
@@ -117,9 +117,11 @@ typedef void (*PyOS_sighandler_t)(int);
 PyAPI_FUNC(PyOS_sighandler_t) PyOS_getsig(int);
 PyAPI_FUNC(PyOS_sighandler_t) PyOS_setsig(int, PyOS_sighandler_t);
 
+#ifndef Py_LIMITED_API
 /* Random */
 PyAPI_FUNC(int) _PyOS_URandom(void *buffer, Py_ssize_t size);
 PyAPI_FUNC(int) _PyOS_URandomNonblock(void *buffer, Py_ssize_t size);
+#endif /* !Py_LIMITED_API */
 
 #ifdef __cplusplus
 }
diff --git a/Include/pystate.h b/Include/pystate.h
index ff0d4fe..afc3c0c 100644
--- a/Include/pystate.h
+++ b/Include/pystate.h
@@ -157,7 +157,9 @@ typedef struct _ts {
 PyAPI_FUNC(PyInterpreterState *) PyInterpreterState_New(void);
 PyAPI_FUNC(void) PyInterpreterState_Clear(PyInterpreterState *);
 PyAPI_FUNC(void) PyInterpreterState_Delete(PyInterpreterState *);
+#ifndef Py_LIMITED_API
 PyAPI_FUNC(int) _PyState_AddModule(PyObject*, struct PyModuleDef*);
+#endif /* !Py_LIMITED_API */
 #if !defined(Py_LIMITED_API) || Py_LIMITED_API+0 >= 0x03030000
 /* New in 3.3 */
 PyAPI_FUNC(int) PyState_AddModule(PyObject*, struct PyModuleDef*);
@@ -169,14 +171,20 @@ PyAPI_FUNC(void) _PyState_ClearModules(void);
 #endif
 
 PyAPI_FUNC(PyThreadState *) PyThreadState_New(PyInterpreterState *);
+#ifndef Py_LIMITED_API
 PyAPI_FUNC(PyThreadState *) _PyThreadState_Prealloc(PyInterpreterState *);
 PyAPI_FUNC(void) _PyThreadState_Init(PyThreadState *);
+#endif /* !Py_LIMITED_API */
 PyAPI_FUNC(void) PyThreadState_Clear(PyThreadState *);
 PyAPI_FUNC(void) PyThreadState_Delete(PyThreadState *);
+#ifndef Py_LIMITED_API
 PyAPI_FUNC(void) _PyThreadState_DeleteExcept(PyThreadState *tstate);
+#endif /* !Py_LIMITED_API */
 #ifdef WITH_THREAD
 PyAPI_FUNC(void) PyThreadState_DeleteCurrent(void);
+#ifndef Py_LIMITED_API
 PyAPI_FUNC(void) _PyGILState_Reinit(void);
+#endif /* !Py_LIMITED_API */
 #endif
 
 /* Return the current thread state. The global interpreter lock must be held.
@@ -184,9 +192,11 @@ PyAPI_FUNC(void) _PyGILState_Reinit(void);
  * the caller needn't check for NULL). */
 PyAPI_FUNC(PyThreadState *) PyThreadState_Get(void);
 
+#ifndef Py_LIMITED_API
 /* Similar to PyThreadState_Get(), but don't issue a fatal error
  * if it is NULL. */
 PyAPI_FUNC(PyThreadState *) _PyThreadState_UncheckedGet(void);
+#endif /* !Py_LIMITED_API */
 
 PyAPI_FUNC(PyThreadState *) PyThreadState_Swap(PyThreadState *);
 PyAPI_FUNC(PyObject *) PyThreadState_GetDict(void);
diff --git a/Include/pystrhex.h b/Include/pystrhex.h
index 1dc1255..66a30e2 100644
--- a/Include/pystrhex.h
+++ b/Include/pystrhex.h
@@ -5,10 +5,12 @@
 extern "C" {
 #endif
 
+#ifndef Py_LIMITED_API
 /* Returns a str() containing the hex representation of argbuf. */
 PyAPI_FUNC(PyObject*) _Py_strhex(const char* argbuf, const Py_ssize_t arglen);
 /* Returns a bytes() containing the ASCII hex representation of argbuf. */
 PyAPI_FUNC(PyObject*) _Py_strhex_bytes(const char* argbuf, const Py_ssize_t arglen);
+#endif /* !Py_LIMITED_API */
 
 #ifdef __cplusplus
 }
diff --git a/Include/sysmodule.h b/Include/sysmodule.h
index cde10ac..c5547ff 100644
--- a/Include/sysmodule.h
+++ b/Include/sysmodule.h
@@ -8,11 +8,11 @@ extern "C" {
 #endif
 
 PyAPI_FUNC(PyObject *) PySys_GetObject(const char *);
+PyAPI_FUNC(int) PySys_SetObject(const char *, PyObject *);
 #ifndef Py_LIMITED_API
 PyAPI_FUNC(PyObject *) _PySys_GetObjectId(_Py_Identifier *key);
-#endif
-PyAPI_FUNC(int) PySys_SetObject(const char *, PyObject *);
 PyAPI_FUNC(int) _PySys_SetObjectId(_Py_Identifier *key, PyObject *);
+#endif
 
 PyAPI_FUNC(void) PySys_SetArgv(int, wchar_t **);
 PyAPI_FUNC(void) PySys_SetArgvEx(int, wchar_t **, int);
diff --git a/Include/traceback.h b/Include/traceback.h
index dbc769b..b587410 100644
--- a/Include/traceback.h
+++ b/Include/traceback.h
@@ -31,6 +31,7 @@ PyAPI_FUNC(void) _PyTraceback_Add(const char *, const char *, int);
 PyAPI_DATA(PyTypeObject) PyTraceBack_Type;
 #define PyTraceBack_Check(v) (Py_TYPE(v) == &PyTraceBack_Type)
 
+#ifndef Py_LIMITED_API
 /* Write the Python traceback into the file 'fd'. For example:
 
        Traceback (most recent call first):
@@ -79,6 +80,7 @@ PyAPI_FUNC(const char*) _Py_DumpTracebackThreads(
     int fd,
     PyInterpreterState *interp,
     PyThreadState *current_tstate);
+#endif /* !Py_LIMITED_API */
 
 #ifndef Py_LIMITED_API
 
diff --git a/Include/unicodeobject.h b/Include/unicodeobject.h
index bcd1aad..38f733b 100644
--- a/Include/unicodeobject.h
+++ b/Include/unicodeobject.h
@@ -2257,6 +2257,7 @@ PyAPI_FUNC(int) _PyUnicode_CheckConsistency(
     int check_content);
 #endif
 
+#ifndef Py_LIMITED_API
 /* Return an interned Unicode object for an Identifier; may fail if there is no memory.*/
 PyAPI_FUNC(PyObject*) _PyUnicode_FromId(_Py_Identifier*);
 /* Clear all static strings. */
@@ -2265,6 +2266,7 @@ PyAPI_FUNC(void) _PyUnicode_ClearStaticStrings(void);
 /* Fast equality check when the inputs are known to be exact unicode types
    and where the hash values are equal (i.e. a very probable match) */
 PyAPI_FUNC(int) _PyUnicode_EQ(PyObject *, PyObject *);
+#endif /* !Py_LIMITED_API */
 
 #ifdef __cplusplus
 }
diff --git a/Misc/NEWS b/Misc/NEWS
index f594f00..fc41d88 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -369,6 +369,8 @@ IDLE
 C API
 -----
 
+- Issue #26900: Excluded underscored names and other private API from limited API.
+
 - Issue #26027: Add support for path-like objects in PyUnicode_FSConverter() &
   PyUnicode_FSDecoder().