bpo-46303: Move fileutils.h private functions to internal C API (GH-30484)

Move almost all private functions of Include/cpython/fileutils.h to
the internal C API Include/internal/pycore_fileutils.h.

Only keep _Py_fopen_obj() in Include/cpython/fileutils.h, since it's
used by _testcapi which must not use the internal C API.

Move EncodeLocaleEx() and DecodeLocaleEx() functions from _testcapi
to _testinternalcapi, since the C API moved to the internal C API.

7 files changed, 117 insertions, 96 deletions

diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c
index be40d68..ea9c048 100644
--- a/Modules/_testcapimodule.c
+++ b/Modules/_testcapimodule.c
@@ -5417,98 +5417,6 @@ bad_get(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 }
 
 
-static PyObject *
-encode_locale_ex(PyObject *self, PyObject *args)
-{
-    PyObject *unicode;
-    int current_locale = 0;
-    wchar_t *wstr;
-    PyObject *res = NULL;
-    const char *errors = NULL;
-
-    if (!PyArg_ParseTuple(args, "U|is", &unicode, &current_locale, &errors)) {
-        return NULL;
-    }
-    wstr = PyUnicode_AsWideCharString(unicode, NULL);
-    if (wstr == NULL) {
-        return NULL;
-    }
-    _Py_error_handler error_handler = _Py_GetErrorHandler(errors);
-
-    char *str = NULL;
-    size_t error_pos;
-    const char *reason = NULL;
-    int ret = _Py_EncodeLocaleEx(wstr,
-                                 &str, &error_pos, &reason,
-                                 current_locale, error_handler);
-    PyMem_Free(wstr);
-
-    switch(ret) {
-    case 0:
-        res = PyBytes_FromString(str);
-        PyMem_RawFree(str);
-        break;
-    case -1:
-        PyErr_NoMemory();
-        break;
-    case -2:
-        PyErr_Format(PyExc_RuntimeError, "encode error: pos=%zu, reason=%s",
-                     error_pos, reason);
-        break;
-    case -3:
-        PyErr_SetString(PyExc_ValueError, "unsupported error handler");
-        break;
-    default:
-        PyErr_SetString(PyExc_ValueError, "unknown error code");
-        break;
-    }
-    return res;
-}
-
-
-static PyObject *
-decode_locale_ex(PyObject *self, PyObject *args)
-{
-    char *str;
-    int current_locale = 0;
-    PyObject *res = NULL;
-    const char *errors = NULL;
-
-    if (!PyArg_ParseTuple(args, "y|is", &str, &current_locale, &errors)) {
-        return NULL;
-    }
-    _Py_error_handler error_handler = _Py_GetErrorHandler(errors);
-
-    wchar_t *wstr = NULL;
-    size_t wlen = 0;
-    const char *reason = NULL;
-    int ret = _Py_DecodeLocaleEx(str,
-                                 &wstr, &wlen, &reason,
-                                 current_locale, error_handler);
-
-    switch(ret) {
-    case 0:
-        res = PyUnicode_FromWideChar(wstr, wlen);
-        PyMem_RawFree(wstr);
-        break;
-    case -1:
-        PyErr_NoMemory();
-        break;
-    case -2:
-        PyErr_Format(PyExc_RuntimeError, "decode error: pos=%zu, reason=%s",
-                     wlen, reason);
-        break;
-    case -3:
-        PyErr_SetString(PyExc_ValueError, "unsupported error handler");
-        break;
-    default:
-        PyErr_SetString(PyExc_ValueError, "unknown error code");
-        break;
-    }
-    return res;
-}
-
-
 #ifdef Py_REF_DEBUG
 static PyObject *
 negative_refcount(PyObject *self, PyObject *Py_UNUSED(args))
@@ -6125,8 +6033,6 @@ static PyMethodDef TestMethods[] = {
     {"test_pythread_tss_key_state", test_pythread_tss_key_state, METH_VARARGS},
     {"hamt", new_hamt, METH_NOARGS},
     {"bad_get", (PyCFunction)(void(*)(void))bad_get, METH_FASTCALL},
-    {"EncodeLocaleEx", encode_locale_ex, METH_VARARGS},
-    {"DecodeLocaleEx", decode_locale_ex, METH_VARARGS},
 #ifdef Py_REF_DEBUG
     {"negative_refcount", negative_refcount, METH_NOARGS},
 #endif
diff --git a/Modules/_testinternalcapi.c b/Modules/_testinternalcapi.c
index 19babb0..9deba35 100644
--- a/Modules/_testinternalcapi.c
+++ b/Modules/_testinternalcapi.c
@@ -399,6 +399,98 @@ get_getpath_codeobject(PyObject *self, PyObject *Py_UNUSED(args)) {
 }
 
 
+static PyObject *
+encode_locale_ex(PyObject *self, PyObject *args)
+{
+    PyObject *unicode;
+    int current_locale = 0;
+    wchar_t *wstr;
+    PyObject *res = NULL;
+    const char *errors = NULL;
+
+    if (!PyArg_ParseTuple(args, "U|is", &unicode, &current_locale, &errors)) {
+        return NULL;
+    }
+    wstr = PyUnicode_AsWideCharString(unicode, NULL);
+    if (wstr == NULL) {
+        return NULL;
+    }
+    _Py_error_handler error_handler = _Py_GetErrorHandler(errors);
+
+    char *str = NULL;
+    size_t error_pos;
+    const char *reason = NULL;
+    int ret = _Py_EncodeLocaleEx(wstr,
+                                 &str, &error_pos, &reason,
+                                 current_locale, error_handler);
+    PyMem_Free(wstr);
+
+    switch(ret) {
+    case 0:
+        res = PyBytes_FromString(str);
+        PyMem_RawFree(str);
+        break;
+    case -1:
+        PyErr_NoMemory();
+        break;
+    case -2:
+        PyErr_Format(PyExc_RuntimeError, "encode error: pos=%zu, reason=%s",
+                     error_pos, reason);
+        break;
+    case -3:
+        PyErr_SetString(PyExc_ValueError, "unsupported error handler");
+        break;
+    default:
+        PyErr_SetString(PyExc_ValueError, "unknown error code");
+        break;
+    }
+    return res;
+}
+
+
+static PyObject *
+decode_locale_ex(PyObject *self, PyObject *args)
+{
+    char *str;
+    int current_locale = 0;
+    PyObject *res = NULL;
+    const char *errors = NULL;
+
+    if (!PyArg_ParseTuple(args, "y|is", &str, &current_locale, &errors)) {
+        return NULL;
+    }
+    _Py_error_handler error_handler = _Py_GetErrorHandler(errors);
+
+    wchar_t *wstr = NULL;
+    size_t wlen = 0;
+    const char *reason = NULL;
+    int ret = _Py_DecodeLocaleEx(str,
+                                 &wstr, &wlen, &reason,
+                                 current_locale, error_handler);
+
+    switch(ret) {
+    case 0:
+        res = PyUnicode_FromWideChar(wstr, wlen);
+        PyMem_RawFree(wstr);
+        break;
+    case -1:
+        PyErr_NoMemory();
+        break;
+    case -2:
+        PyErr_Format(PyExc_RuntimeError, "decode error: pos=%zu, reason=%s",
+                     wlen, reason);
+        break;
+    case -3:
+        PyErr_SetString(PyExc_ValueError, "unsupported error handler");
+        break;
+    default:
+        PyErr_SetString(PyExc_ValueError, "unknown error code");
+        break;
+    }
+    return res;
+}
+
+
 static PyMethodDef TestMethods[] = {
     {"get_configs", get_configs, METH_NOARGS},
     {"get_recursion_depth", get_recursion_depth, METH_NOARGS},
@@ -413,6 +505,8 @@ static PyMethodDef TestMethods[] = {
     {"test_edit_cost", test_edit_cost, METH_NOARGS},
     {"normalize_path", normalize_path, METH_O, NULL},
     {"get_getpath_codeobject", get_getpath_codeobject, METH_NOARGS, NULL},
+    {"EncodeLocaleEx", encode_locale_ex, METH_VARARGS},
+    {"DecodeLocaleEx", decode_locale_ex, METH_VARARGS},
     {NULL, NULL} /* sentinel */
 };
 
diff --git a/Modules/_tracemalloc.c b/Modules/_tracemalloc.c
index 68e5f0d..b838439 100644
--- a/Modules/_tracemalloc.c
+++ b/Modules/_tracemalloc.c
@@ -1,8 +1,9 @@
 #include "Python.h"
+#include "pycore_fileutils.h"     // _Py_write_noraise()
 #include "pycore_gc.h"            // PyGC_Head
+#include "pycore_hashtable.h"     // _Py_hashtable_t
 #include "pycore_pymem.h"         // _Py_tracemalloc_config
 #include "pycore_traceback.h"
-#include "pycore_hashtable.h"
 #include <pycore_frame.h>
 
 #include <stdlib.h>               // malloc()
diff --git a/Modules/mmapmodule.c b/Modules/mmapmodule.c
index 742bcb3..7c9c28f 100644
--- a/Modules/mmapmodule.c
+++ b/Modules/mmapmodule.c
@@ -18,8 +18,13 @@
  / ftp://squirl.nightmare.com/pub/python/python-ext.
 */
 
+#ifndef Py_BUILD_CORE_BUILTIN
+#  define Py_BUILD_CORE_MODULE 1
+#endif
+
 #define PY_SSIZE_T_CLEAN
 #include <Python.h>
+#include "pycore_fileutils.h"     // _Py_stat_struct
 #include "structmember.h"         // PyMemberDef
 #include <stddef.h>               // offsetof()
 
diff --git a/Modules/ossaudiodev.c b/Modules/ossaudiodev.c
index 4bab9a5..c9e788f 100644
--- a/Modules/ossaudiodev.c
+++ b/Modules/ossaudiodev.c
@@ -17,8 +17,13 @@
  * $Id$
  */
 
+#ifndef Py_BUILD_CORE_BUILTIN
+#  define Py_BUILD_CORE_MODULE 1
+#endif
+
 #define PY_SSIZE_T_CLEAN
 #include "Python.h"
+#include "pycore_fileutils.h"     // _Py_write()
 #include "structmember.h"         // PyMemberDef
 
 #include <stdlib.h>               // getenv()
diff --git a/Modules/selectmodule.c b/Modules/selectmodule.c
index ff1c028..367e299 100644
--- a/Modules/selectmodule.c
+++ b/Modules/selectmodule.c
@@ -4,11 +4,16 @@
    have any value except INVALID_SOCKET.
 */
 
+#ifndef Py_BUILD_CORE_BUILTIN
+#  define Py_BUILD_CORE_MODULE 1
+#endif
+
 #if defined(HAVE_POLL_H) && !defined(_GNU_SOURCE)
-#define _GNU_SOURCE
+#  define _GNU_SOURCE
 #endif
 
 #include "Python.h"
+#include "pycore_fileutils.h"     // _Py_set_inheritable()
 #include "structmember.h"         // PyMemberDef
 
 #ifdef HAVE_SYS_DEVPOLL_H
diff --git a/Modules/socketmodule.c b/Modules/socketmodule.c
index 89e93c5..ed83f5c 100644
--- a/Modules/socketmodule.c
+++ b/Modules/socketmodule.c
@@ -85,6 +85,10 @@ Local naming conventions:
 
 */
 
+#ifndef Py_BUILD_CORE_BUILTIN
+#  define Py_BUILD_CORE_MODULE 1
+#endif
+
 #ifdef __APPLE__
 // Issue #35569: Expose RFC 3542 socket options.
 #define __APPLE_USE_RFC_3542 1
@@ -103,6 +107,7 @@ Local naming conventions:
 
 #define PY_SSIZE_T_CLEAN
 #include "Python.h"
+#include "pycore_fileutils.h"     // _Py_set_inheritable()
 #include "structmember.h"         // PyMemberDef
 
 #ifdef _Py_MEMORY_SANITIZER