gh-106320: Move private _PySet API to the internal API (#107041)

* Add pycore_setobject.h header file.
* Move the following API to the internal C API:

  * _PySet_Dummy
  * _PySet_NextEntry()
  * _PySet_Update()

Author: vstinner

Include/cpython/setobject.h

@@ -65,8 +65,3 @@ static inline Py_ssize_t PySet_GET_SIZE(PyObject *so) {
     return _PySet_CAST(so)->used;
 }
 #define PySet_GET_SIZE(so) PySet_GET_SIZE(_PyObject_CAST(so))
-
-PyAPI_DATA(PyObject *) _PySet_Dummy;
-
-PyAPI_FUNC(int) _PySet_NextEntry(PyObject *set, Py_ssize_t *pos, PyObject **key, Py_hash_t *hash);
-PyAPI_FUNC(int) _PySet_Update(PyObject *set, PyObject *iterable);

Include/internal/pycore_pymem.h

@@ -95,4 +95,4 @@ PyAPI_FUNC(int) _PyMem_SetupAllocators(PyMemAllocatorName allocator);
 #ifdef __cplusplus
 }
 #endif
-#endif /* !Py_INTERNAL_PYMEM_H */
+#endif  // !Py_INTERNAL_PYMEM_H

Include/internal/pycore_setobject.h

@@ -0,0 +1,25 @@
+#ifndef Py_INTERNAL_SETOBJECT_H
+#define Py_INTERNAL_SETOBJECT_H
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef Py_BUILD_CORE
+#  error "this header requires Py_BUILD_CORE define"
+#endif
+
+// _pickle shared extension uses _PySet_NextEntry() and _PySet_Update()
+PyAPI_FUNC(int) _PySet_NextEntry(
+    PyObject *set,
+    Py_ssize_t *pos,
+    PyObject **key,
+    Py_hash_t *hash);
+PyAPI_FUNC(int) _PySet_Update(PyObject *set, PyObject *iterable);
+
+// Export _PySet_Dummy for the gdb plugin's benefit
+PyAPI_DATA(PyObject *) _PySet_Dummy;
+
+#ifdef __cplusplus
+}
+#endif
+#endif  // !Py_INTERNAL_SETOBJECT_H

Makefile.pre.in

@@ -1798,6 +1798,7 @@ PYTHON_HEADERS= \
 		$(srcdir)/Include/internal/pycore_runtime.h \
 		$(srcdir)/Include/internal/pycore_runtime_init_generated.h \
 		$(srcdir)/Include/internal/pycore_runtime_init.h \
+		$(srcdir)/Include/internal/pycore_setobject.h \
 		$(srcdir)/Include/internal/pycore_signal.h \
 		$(srcdir)/Include/internal/pycore_sliceobject.h \
 		$(srcdir)/Include/internal/pycore_strhex.h \

Modules/_abc.c

@@ -7,6 +7,7 @@
 #include "pycore_moduleobject.h"  // _PyModule_GetState()
 #include "pycore_object.h"        // _PyType_GetSubclasses()
 #include "pycore_runtime.h"       // _Py_ID()
+#include "pycore_setobject.h"     // _PySet_NextEntry()
 #include "pycore_typeobject.h"    // _PyType_GetMRO()
 #include "pycore_weakref.h"       // _PyWeakref_GET_REF()
 #include "clinic/_abc.c.h"

Modules/_pickle.c

@@ -15,6 +15,7 @@
 #include "pycore_object.h"        // _PyNone_Type
 #include "pycore_pystate.h"       // _PyThreadState_GET()
 #include "pycore_runtime.h"       // _Py_ID()
+#include "pycore_setobject.h"     // _PySet_NextEntry()
 #include "structmember.h"         // PyMemberDef
 
 #include <stdlib.h>               // strtol()

Objects/codeobject.c

@@ -8,6 +8,7 @@
 #include "pycore_interp.h"        // PyInterpreterState.co_extra_freefuncs
 #include "pycore_opcode.h"        // _PyOpcode_Deopt
 #include "pycore_pystate.h"       // _PyInterpreterState_GET()
+#include "pycore_setobject.h"     // _PySet_NextEntry()
 #include "pycore_tuple.h"         // _PyTuple_ITEMS()
 #include "clinic/codeobject.c.h"
 

Objects/dictobject.c

@@ -121,6 +121,7 @@ As a consequence of this, split keys have a maximum size of 16.
 #include "pycore_object.h"        // _PyObject_GC_TRACK()
 #include "pycore_pyerrors.h"      // _PyErr_GetRaisedException()
 #include "pycore_pystate.h"       // _PyThreadState_GET()
+#include "pycore_setobject.h"     // _PySet_NextEntry()
 #include "stringlib/eq.h"         // unicode_eq()
 
 #include <stdbool.h>

Objects/setobject.c

@@ -34,6 +34,7 @@
 #include "Python.h"
 #include "pycore_modsupport.h"    // _PyArg_NoKwnames()
 #include "pycore_object.h"        // _PyObject_GC_UNTRACK()
+#include "pycore_setobject.h"     // _PySet_NextEntry() definition
 #include <stddef.h>               // offsetof()
 
 /* Object used as dummy key to fill deleted entries */

PCbuild/pythoncore.vcxproj

@@ -261,6 +261,7 @@
     <ClInclude Include="..\Include\internal\pycore_runtime.h" />
     <ClInclude Include="..\Include\internal\pycore_runtime_init.h" />
     <ClInclude Include="..\Include\internal\pycore_runtime_init_generated.h" />
+    <ClInclude Include="..\Include\internal\pycore_setobject.h" />
     <ClInclude Include="..\Include\internal\pycore_signal.h" />
     <ClInclude Include="..\Include\internal\pycore_sliceobject.h" />
     <ClInclude Include="..\Include\internal\pycore_strhex.h" />