Move _PyBytesWriter_CreateByteArray() to the internal C API

Author: vstinner

Include/cpython/bytesobject.h

@@ -48,8 +48,6 @@ typedef struct PyBytesWriter PyBytesWriter;
 
 PyAPI_FUNC(PyBytesWriter *) PyBytesWriter_Create(
     Py_ssize_t size);
-PyAPI_FUNC(PyBytesWriter*) _PyBytesWriter_CreateByteArray(
-    Py_ssize_t size);
 PyAPI_FUNC(void) PyBytesWriter_Discard(
     PyBytesWriter *writer);
 PyAPI_FUNC(PyObject*) PyBytesWriter_Finish(

Include/internal/pycore_bytesobject.h

@@ -142,6 +142,10 @@ PyAPI_FUNC(void*) _PyBytesWriter_WriteBytes(_PyBytesWriter *writer,
     const void *bytes,
     Py_ssize_t size);
 
+// Export for '_testcapi' shared extension.
+PyAPI_FUNC(PyBytesWriter*) _PyBytesWriter_CreateByteArray(
+    Py_ssize_t size);
+
 #ifdef __cplusplus
 }
 #endif

Modules/_testcapi/bytes.c

@@ -1,6 +1,11 @@
+// Use pycore_bytes.h
+#define PYTESTCAPI_NEED_INTERNAL_API
+
 #include "parts.h"
 #include "util.h"
 
+#include "pycore_bytesobject.h"   // _PyBytesWriter_CreateByteArray()
+
 
 /* Test _PyBytes_Resize() */
 static PyObject *