add ydb deps

1 files changed, 2679 insertions, 0 deletions

diff --git a/contrib/tools/python3/src/Python/fileutils.c b/contrib/tools/python3/src/Python/fileutils.c
new file mode 100644
index 0000000000..e1af39ddf0
--- /dev/null
+++ b/contrib/tools/python3/src/Python/fileutils.c
@@ -0,0 +1,2679 @@
+#include "Python.h"
+#include "pycore_fileutils.h"     // fileutils definitions
+#include "pycore_runtime.h"       // _PyRuntime
+#include "osdefs.h"               // SEP
+#include <locale.h>
+#include <stdlib.h>               // mbstowcs()
+
+#ifdef MS_WINDOWS
+#  include <malloc.h>
+#  include <windows.h>
+#  include <pathcch.h>            // PathCchCombineEx
+extern int winerror_to_errno(int);
+#endif
+
+#ifdef HAVE_LANGINFO_H
+#include <langinfo.h>
+#endif
+
+#ifdef HAVE_SYS_IOCTL_H
+#include <sys/ioctl.h>
+#endif
+
+#ifdef HAVE_NON_UNICODE_WCHAR_T_REPRESENTATION
+#error #include <iconv.h>
+#endif
+
+#ifdef HAVE_FCNTL_H
+#include <fcntl.h>
+#endif /* HAVE_FCNTL_H */
+
+#ifdef O_CLOEXEC
+/* Does open() support the O_CLOEXEC flag? Possible values:
+
+   -1: unknown
+    0: open() ignores O_CLOEXEC flag, ex: Linux kernel older than 2.6.23
+    1: open() supports O_CLOEXEC flag, close-on-exec is set
+
+   The flag is used by _Py_open(), _Py_open_noraise(), io.FileIO
+   and os.open(). */
+int _Py_open_cloexec_works = -1;
+#endif
+
+// The value must be the same in unicodeobject.c.
+#define MAX_UNICODE 0x10ffff
+
+// mbstowcs() and mbrtowc() errors
+static const size_t DECODE_ERROR = ((size_t)-1);
+static const size_t INCOMPLETE_CHARACTER = (size_t)-2;
+
+
+static int
+get_surrogateescape(_Py_error_handler errors, int *surrogateescape)
+{
+    switch (errors)
+    {
+    case _Py_ERROR_STRICT:
+        *surrogateescape = 0;
+        return 0;
+    case _Py_ERROR_SURROGATEESCAPE:
+        *surrogateescape = 1;
+        return 0;
+    default:
+        return -1;
+    }
+}
+
+
+PyObject *
+_Py_device_encoding(int fd)
+{
+    int valid;
+    Py_BEGIN_ALLOW_THREADS
+    _Py_BEGIN_SUPPRESS_IPH
+    valid = isatty(fd);
+    _Py_END_SUPPRESS_IPH
+    Py_END_ALLOW_THREADS
+    if (!valid)
+        Py_RETURN_NONE;
+
+#if defined(MS_WINDOWS)
+    UINT cp;
+    if (fd == 0)
+        cp = GetConsoleCP();
+    else if (fd == 1 || fd == 2)
+        cp = GetConsoleOutputCP();
+    else
+        cp = 0;
+    /* GetConsoleCP() and GetConsoleOutputCP() return 0 if the application
+       has no console */
+    if (cp == 0) {
+        Py_RETURN_NONE;
+    }
+
+    return PyUnicode_FromFormat("cp%u", (unsigned int)cp);
+#else
+    if (_PyRuntime.preconfig.utf8_mode) {
+        _Py_DECLARE_STR(utf_8, "utf-8");
+        return Py_NewRef(&_Py_STR(utf_8));
+    }
+    return _Py_GetLocaleEncodingObject();
+#endif
+}
+
+
+static size_t
+is_valid_wide_char(wchar_t ch)
+{
+#ifdef HAVE_NON_UNICODE_WCHAR_T_REPRESENTATION
+    /* Oracle Solaris doesn't use Unicode code points as wchar_t encoding
+       for non-Unicode locales, which makes values higher than MAX_UNICODE
+       possibly valid. */
+    return 1;
+#endif
+    if (Py_UNICODE_IS_SURROGATE(ch)) {
+        // Reject lone surrogate characters
+        return 0;
+    }
+    if (ch > MAX_UNICODE) {
+        // bpo-35883: Reject characters outside [U+0000; U+10ffff] range.
+        // The glibc mbstowcs() UTF-8 decoder does not respect the RFC 3629,
+        // it creates characters outside the [U+0000; U+10ffff] range:
+        // https://sourceware.org/bugzilla/show_bug.cgi?id=2373
+        return 0;
+    }
+    return 1;
+}
+
+
+static size_t
+_Py_mbstowcs(wchar_t *dest, const char *src, size_t n)
+{
+    size_t count = mbstowcs(dest, src, n);
+    if (dest != NULL && count != DECODE_ERROR) {
+        for (size_t i=0; i < count; i++) {
+            wchar_t ch = dest[i];
+            if (!is_valid_wide_char(ch)) {
+                return DECODE_ERROR;
+            }
+        }
+    }
+    return count;
+}
+
+
+#ifdef HAVE_MBRTOWC
+static size_t
+_Py_mbrtowc(wchar_t *pwc, const char *str, size_t len, mbstate_t *pmbs)
+{
+    assert(pwc != NULL);
+    size_t count = mbrtowc(pwc, str, len, pmbs);
+    if (count != 0 && count != DECODE_ERROR && count != INCOMPLETE_CHARACTER) {
+        if (!is_valid_wide_char(*pwc)) {
+            return DECODE_ERROR;
+        }
+    }
+    return count;
+}
+#endif
+
+
+#if !defined(_Py_FORCE_UTF8_FS_ENCODING) && !defined(MS_WINDOWS)
+
+#define USE_FORCE_ASCII
+
+extern int _Py_normalize_encoding(const char *, char *, size_t);
+
+/* Workaround FreeBSD and OpenIndiana locale encoding issue with the C locale
+   and POSIX locale. nl_langinfo(CODESET) announces an alias of the
+   ASCII encoding, whereas mbstowcs() and wcstombs() functions use the
+   ISO-8859-1 encoding. The problem is that os.fsencode() and os.fsdecode() use
+   locale.getpreferredencoding() codec. For example, if command line arguments
+   are decoded by mbstowcs() and encoded back by os.fsencode(), we get a
+   UnicodeEncodeError instead of retrieving the original byte string.
+
+   The workaround is enabled if setlocale(LC_CTYPE, NULL) returns "C",
+   nl_langinfo(CODESET) announces "ascii" (or an alias to ASCII), and at least
+   one byte in range 0x80-0xff can be decoded from the locale encoding. The
+   workaround is also enabled on error, for example if getting the locale
+   failed.
+
+   On HP-UX with the C locale or the POSIX locale, nl_langinfo(CODESET)
+   announces "roman8" but mbstowcs() uses Latin1 in practice. Force also the
+   ASCII encoding in this case.
+
+   Values of force_ascii:
+
+       1: the workaround is used: Py_EncodeLocale() uses
+          encode_ascii_surrogateescape() and Py_DecodeLocale() uses
+          decode_ascii()
+       0: the workaround is not used: Py_EncodeLocale() uses wcstombs() and
+          Py_DecodeLocale() uses mbstowcs()
+      -1: unknown, need to call check_force_ascii() to get the value
+*/
+static int force_ascii = -1;
+
+static int
+check_force_ascii(void)
+{
+    char *loc = setlocale(LC_CTYPE, NULL);
+    if (loc == NULL) {
+        goto error;
+    }
+    if (strcmp(loc, "C") != 0 && strcmp(loc, "POSIX") != 0) {
+        /* the LC_CTYPE locale is different than C and POSIX */
+        return 0;
+    }
+
+#if defined(HAVE_LANGINFO_H) && defined(CODESET)
+    const char *codeset = nl_langinfo(CODESET);
+    if (!codeset || codeset[0] == '\0') {
+        /* CODESET is not set or empty */
+        goto error;
+    }
+
+    char encoding[20];   /* longest name: "iso_646.irv_1991\0" */
+    if (!_Py_normalize_encoding(codeset, encoding, sizeof(encoding))) {
+        goto error;
+    }
+
+#ifdef __hpux
+    if (strcmp(encoding, "roman8") == 0) {
+        unsigned char ch;
+        wchar_t wch;
+        size_t res;
+
+        ch = (unsigned char)0xA7;
+        res = _Py_mbstowcs(&wch, (char*)&ch, 1);
+        if (res != DECODE_ERROR && wch == L'\xA7') {
+            /* On HP-UX with C locale or the POSIX locale,
+               nl_langinfo(CODESET) announces "roman8", whereas mbstowcs() uses
+               Latin1 encoding in practice. Force ASCII in this case.
+
+               Roman8 decodes 0xA7 to U+00CF. Latin1 decodes 0xA7 to U+00A7. */
+            return 1;
+        }
+    }
+#else
+    const char* ascii_aliases[] = {
+        "ascii",
+        /* Aliases from Lib/encodings/aliases.py */
+        "646",
+        "ansi_x3.4_1968",
+        "ansi_x3.4_1986",
+        "ansi_x3_4_1968",
+        "cp367",
+        "csascii",
+        "ibm367",
+        "iso646_us",
+        "iso_646.irv_1991",
+        "iso_ir_6",
+        "us",
+        "us_ascii",
+        NULL
+    };
+
+    int is_ascii = 0;
+    for (const char **alias=ascii_aliases; *alias != NULL; alias++) {
+        if (strcmp(encoding, *alias) == 0) {
+            is_ascii = 1;
+            break;
+        }
+    }
+    if (!is_ascii) {
+        /* nl_langinfo(CODESET) is not "ascii" or an alias of ASCII */
+        return 0;
+    }
+
+    for (unsigned int i=0x80; i<=0xff; i++) {
+        char ch[1];
+        wchar_t wch[1];
+        size_t res;
+
+        unsigned uch = (unsigned char)i;
+        ch[0] = (char)uch;
+        res = _Py_mbstowcs(wch, ch, 1);
+        if (res != DECODE_ERROR) {
+            /* decoding a non-ASCII character from the locale encoding succeed:
+               the locale encoding is not ASCII, force ASCII */
+            return 1;
+        }
+    }
+    /* None of the bytes in the range 0x80-0xff can be decoded from the locale
+       encoding: the locale encoding is really ASCII */
+#endif   /* !defined(__hpux) */
+    return 0;
+#else
+    /* nl_langinfo(CODESET) is not available: always force ASCII */
+    return 1;
+#endif   /* defined(HAVE_LANGINFO_H) && defined(CODESET) */
+
+error:
+    /* if an error occurred, force the ASCII encoding */
+    return 1;
+}
+
+
+int
+_Py_GetForceASCII(void)
+{
+    if (force_ascii == -1) {
+        force_ascii = check_force_ascii();
+    }
+    return force_ascii;
+}
+
+
+void
+_Py_ResetForceASCII(void)
+{
+    force_ascii = -1;
+}
+
+
+static int
+encode_ascii(const wchar_t *text, char **str,
+             size_t *error_pos, const char **reason,
+             int raw_malloc, _Py_error_handler errors)
+{
+    char *result = NULL, *out;
+    size_t len, i;
+    wchar_t ch;
+
+    int surrogateescape;
+    if (get_surrogateescape(errors, &surrogateescape) < 0) {
+        return -3;
+    }
+
+    len = wcslen(text);
+
+    /* +1 for NULL byte */
+    if (raw_malloc) {
+        result = PyMem_RawMalloc(len + 1);
+    }
+    else {
+        result = PyMem_Malloc(len + 1);
+    }
+    if (result == NULL) {
+        return -1;
+    }
+
+    out = result;
+    for (i=0; i<len; i++) {
+        ch = text[i];
+
+        if (ch <= 0x7f) {
+            /* ASCII character */
+            *out++ = (char)ch;
+        }
+        else if (surrogateescape && 0xdc80 <= ch && ch <= 0xdcff) {
+            /* UTF-8b surrogate */
+            *out++ = (char)(ch - 0xdc00);
+        }
+        else {
+            if (raw_malloc) {
+                PyMem_RawFree(result);
+            }
+            else {
+                PyMem_Free(result);
+            }
+            if (error_pos != NULL) {
+                *error_pos = i;
+            }
+            if (reason) {
+                *reason = "encoding error";
+            }
+            return -2;
+        }
+    }
+    *out = '\0';
+    *str = result;
+    return 0;
+}
+#else
+int
+_Py_GetForceASCII(void)
+{
+    return 0;
+}
+
+void
+_Py_ResetForceASCII(void)
+{
+    /* nothing to do */
+}
+#endif   /* !defined(_Py_FORCE_UTF8_FS_ENCODING) && !defined(MS_WINDOWS) */
+
+
+#if !defined(HAVE_MBRTOWC) || defined(USE_FORCE_ASCII)
+static int
+decode_ascii(const char *arg, wchar_t **wstr, size_t *wlen,
+             const char **reason, _Py_error_handler errors)
+{
+    wchar_t *res;
+    unsigned char *in;
+    wchar_t *out;
+    size_t argsize = strlen(arg) + 1;
+
+    int surrogateescape;
+    if (get_surrogateescape(errors, &surrogateescape) < 0) {
+        return -3;
+    }
+
+    if (argsize > PY_SSIZE_T_MAX / sizeof(wchar_t)) {
+        return -1;
+    }
+    res = PyMem_RawMalloc(argsize * sizeof(wchar_t));
+    if (!res) {
+        return -1;
+    }
+
+    out = res;
+    for (in = (unsigned char*)arg; *in; in++) {
+        unsigned char ch = *in;
+        if (ch < 128) {
+            *out++ = ch;
+        }
+        else {
+            if (!surrogateescape) {
+                PyMem_RawFree(res);
+                if (wlen) {
+                    *wlen = in - (unsigned char*)arg;
+                }
+                if (reason) {
+                    *reason = "decoding error";
+                }
+                return -2;
+            }
+            *out++ = 0xdc00 + ch;
+        }
+    }
+    *out = 0;
+
+    if (wlen != NULL) {
+        *wlen = out - res;
+    }
+    *wstr = res;
+    return 0;
+}
+#endif   /* !HAVE_MBRTOWC */
+
+static int
+decode_current_locale(const char* arg, wchar_t **wstr, size_t *wlen,
+                      const char **reason, _Py_error_handler errors)
+{
+    wchar_t *res;
+    size_t argsize;
+    size_t count;
+#ifdef HAVE_MBRTOWC
+    unsigned char *in;
+    wchar_t *out;
+    mbstate_t mbs;
+#endif
+
+    int surrogateescape;
+    if (get_surrogateescape(errors, &surrogateescape) < 0) {
+        return -3;
+    }
+
+#ifdef HAVE_BROKEN_MBSTOWCS
+    /* Some platforms have a broken implementation of
+     * mbstowcs which does not count the characters that
+     * would result from conversion.  Use an upper bound.
+     */
+    argsize = strlen(arg);
+#else
+    argsize = _Py_mbstowcs(NULL, arg, 0);
+#endif
+    if (argsize != DECODE_ERROR) {
+        if (argsize > PY_SSIZE_T_MAX / sizeof(wchar_t) - 1) {
+            return -1;
+        }
+        res = (wchar_t *)PyMem_RawMalloc((argsize + 1) * sizeof(wchar_t));
+        if (!res) {
+            return -1;
+        }
+
+        count = _Py_mbstowcs(res, arg, argsize + 1);
+        if (count != DECODE_ERROR) {
+            *wstr = res;
+            if (wlen != NULL) {
+                *wlen = count;
+            }
+            return 0;
+        }
+        PyMem_RawFree(res);
+    }
+
+    /* Conversion failed. Fall back to escaping with surrogateescape. */
+#ifdef HAVE_MBRTOWC
+    /* Try conversion with mbrtwoc (C99), and escape non-decodable bytes. */
+
+    /* Overallocate; as multi-byte characters are in the argument, the
+       actual output could use less memory. */
+    argsize = strlen(arg) + 1;
+    if (argsize > PY_SSIZE_T_MAX / sizeof(wchar_t)) {
+        return -1;
+    }
+    res = (wchar_t*)PyMem_RawMalloc(argsize * sizeof(wchar_t));
+    if (!res) {
+        return -1;
+    }
+
+    in = (unsigned char*)arg;
+    out = res;
+    memset(&mbs, 0, sizeof mbs);
+    while (argsize) {
+        size_t converted = _Py_mbrtowc(out, (char*)in, argsize, &mbs);
+        if (converted == 0) {
+            /* Reached end of string; null char stored. */
+            break;
+        }
+
+        if (converted == INCOMPLETE_CHARACTER) {
+            /* Incomplete character. This should never happen,
+               since we provide everything that we have -
+               unless there is a bug in the C library, or I
+               misunderstood how mbrtowc works. */
+            goto decode_error;
+        }
+
+        if (converted == DECODE_ERROR) {
+            if (!surrogateescape) {
+                goto decode_error;
+            }
+
+            /* Decoding error. Escape as UTF-8b, and start over in the initial
+               shift state. */
+            *out++ = 0xdc00 + *in++;
+            argsize--;
+            memset(&mbs, 0, sizeof mbs);
+            continue;
+        }
+
+        // _Py_mbrtowc() reject lone surrogate characters
+        assert(!Py_UNICODE_IS_SURROGATE(*out));
+
+        /* successfully converted some bytes */
+        in += converted;
+        argsize -= converted;
+        out++;
+    }
+    if (wlen != NULL) {
+        *wlen = out - res;
+    }
+    *wstr = res;
+    return 0;
+
+decode_error:
+    PyMem_RawFree(res);
+    if (wlen) {
+        *wlen = in - (unsigned char*)arg;
+    }
+    if (reason) {
+        *reason = "decoding error";
+    }
+    return -2;
+#else   /* HAVE_MBRTOWC */
+    /* Cannot use C locale for escaping; manually escape as if charset
+       is ASCII (i.e. escape all bytes > 128. This will still roundtrip
+       correctly in the locale's charset, which must be an ASCII superset. */
+    return decode_ascii(arg, wstr, wlen, reason, errors);
+#endif   /* HAVE_MBRTOWC */
+}
+
+
+/* Decode a byte string from the locale encoding.
+
+   Use the strict error handler if 'surrogateescape' is zero.  Use the
+   surrogateescape error handler if 'surrogateescape' is non-zero: undecodable
+   bytes are decoded as characters in range U+DC80..U+DCFF. If a byte sequence
+   can be decoded as a surrogate character, escape the bytes using the
+   surrogateescape error handler instead of decoding them.
+
+   On success, return 0 and write the newly allocated wide character string into
+   *wstr (use PyMem_RawFree() to free the memory). If wlen is not NULL, write
+   the number of wide characters excluding the null character into *wlen.
+
+   On memory allocation failure, return -1.
+
+   On decoding error, return -2. If wlen is not NULL, write the start of
+   invalid byte sequence in the input string into *wlen. If reason is not NULL,
+   write the decoding error message into *reason.
+
+   Return -3 if the error handler 'errors' is not supported.
+
+   Use the Py_EncodeLocaleEx() function to encode the character string back to
+   a byte string. */
+int
+_Py_DecodeLocaleEx(const char* arg, wchar_t **wstr, size_t *wlen,
+                   const char **reason,
+                   int current_locale, _Py_error_handler errors)
+{
+    if (current_locale) {
+#ifdef _Py_FORCE_UTF8_LOCALE
+        return _Py_DecodeUTF8Ex(arg, strlen(arg), wstr, wlen, reason,
+                                errors);
+#else
+        return decode_current_locale(arg, wstr, wlen, reason, errors);
+#endif
+    }
+
+#ifdef _Py_FORCE_UTF8_FS_ENCODING
+    return _Py_DecodeUTF8Ex(arg, strlen(arg), wstr, wlen, reason,
+                            errors);
+#else
+    int use_utf8 = (Py_UTF8Mode == 1);
+#ifdef MS_WINDOWS
+    use_utf8 |= !Py_LegacyWindowsFSEncodingFlag;
+#endif
+    if (use_utf8) {
+        return _Py_DecodeUTF8Ex(arg, strlen(arg), wstr, wlen, reason,
+                                errors);
+    }
+
+#ifdef USE_FORCE_ASCII
+    if (force_ascii == -1) {
+        force_ascii = check_force_ascii();
+    }
+
+    if (force_ascii) {
+        /* force ASCII encoding to workaround mbstowcs() issue */
+        return decode_ascii(arg, wstr, wlen, reason, errors);
+    }
+#endif
+
+    return decode_current_locale(arg, wstr, wlen, reason, errors);
+#endif   /* !_Py_FORCE_UTF8_FS_ENCODING */
+}
+
+
+/* Decode a byte string from the locale encoding with the
+   surrogateescape error handler: undecodable bytes are decoded as characters
+   in range U+DC80..U+DCFF. If a byte sequence can be decoded as a surrogate
+   character, escape the bytes using the surrogateescape error handler instead
+   of decoding them.
+
+   Return a pointer to a newly allocated wide character string, use
+   PyMem_RawFree() to free the memory. If size is not NULL, write the number of
+   wide characters excluding the null character into *size
+
+   Return NULL on decoding error or memory allocation error. If *size* is not
+   NULL, *size is set to (size_t)-1 on memory error or set to (size_t)-2 on
+   decoding error.
+
+   Decoding errors should never happen, unless there is a bug in the C
+   library.
+
+   Use the Py_EncodeLocale() function to encode the character string back to a
+   byte string. */
+wchar_t*
+Py_DecodeLocale(const char* arg, size_t *wlen)
+{
+    wchar_t *wstr;
+    int res = _Py_DecodeLocaleEx(arg, &wstr, wlen,
+                                 NULL, 0,
+                                 _Py_ERROR_SURROGATEESCAPE);
+    if (res != 0) {
+        assert(res != -3);
+        if (wlen != NULL) {
+            *wlen = (size_t)res;
+        }
+        return NULL;
+    }
+    return wstr;
+}
+
+
+static int
+encode_current_locale(const wchar_t *text, char **str,
+                      size_t *error_pos, const char **reason,
+                      int raw_malloc, _Py_error_handler errors)
+{
+    const size_t len = wcslen(text);
+    char *result = NULL, *bytes = NULL;
+    size_t i, size, converted;
+    wchar_t c, buf[2];
+
+    int surrogateescape;
+    if (get_surrogateescape(errors, &surrogateescape) < 0) {
+        return -3;
+    }
+
+    /* The function works in two steps:
+       1. compute the length of the output buffer in bytes (size)
+       2. outputs the bytes */
+    size = 0;
+    buf[1] = 0;
+    while (1) {
+        for (i=0; i < len; i++) {
+            c = text[i];
+            if (c >= 0xdc80 && c <= 0xdcff) {
+                if (!surrogateescape) {
+                    goto encode_error;
+                }
+                /* UTF-8b surrogate */
+                if (bytes != NULL) {
+                    *bytes++ = c - 0xdc00;
+                    size--;
+                }
+                else {
+                    size++;
+                }
+                continue;
+            }
+            else {
+                buf[0] = c;
+                if (bytes != NULL) {
+                    converted = wcstombs(bytes, buf, size);
+                }
+                else {
+                    converted = wcstombs(NULL, buf, 0);
+                }
+                if (converted == DECODE_ERROR) {
+                    goto encode_error;
+                }
+                if (bytes != NULL) {
+                    bytes += converted;
+                    size -= converted;
+                }
+                else {
+                    size += converted;
+                }
+            }
+        }
+        if (result != NULL) {
+            *bytes = '\0';
+            break;
+        }
+
+        size += 1; /* nul byte at the end */
+        if (raw_malloc) {
+            result = PyMem_RawMalloc(size);
+        }
+        else {
+            result = PyMem_Malloc(size);
+        }
+        if (result == NULL) {
+            return -1;
+        }
+        bytes = result;
+    }
+    *str = result;
+    return 0;
+
+encode_error:
+    if (raw_malloc) {
+        PyMem_RawFree(result);
+    }
+    else {
+        PyMem_Free(result);
+    }
+    if (error_pos != NULL) {
+        *error_pos = i;
+    }
+    if (reason) {
+        *reason = "encoding error";
+    }
+    return -2;
+}
+
+
+/* Encode a string to the locale encoding.
+
+   Parameters:
+
+   * raw_malloc: if non-zero, allocate memory using PyMem_RawMalloc() instead
+     of PyMem_Malloc().
+   * current_locale: if non-zero, use the current LC_CTYPE, otherwise use
+     Python filesystem encoding.
+   * errors: error handler like "strict" or "surrogateescape".
+
+   Return value:
+
+    0: success, *str is set to a newly allocated decoded string.
+   -1: memory allocation failure
+   -2: encoding error, set *error_pos and *reason (if set).
+   -3: the error handler 'errors' is not supported.
+ */
+static int
+encode_locale_ex(const wchar_t *text, char **str, size_t *error_pos,
+                 const char **reason,
+                 int raw_malloc, int current_locale, _Py_error_handler errors)
+{
+    if (current_locale) {
+#ifdef _Py_FORCE_UTF8_LOCALE
+        return _Py_EncodeUTF8Ex(text, str, error_pos, reason,
+                                raw_malloc, errors);
+#else
+        return encode_current_locale(text, str, error_pos, reason,
+                                     raw_malloc, errors);
+#endif
+    }
+
+#ifdef _Py_FORCE_UTF8_FS_ENCODING
+    return _Py_EncodeUTF8Ex(text, str, error_pos, reason,
+                            raw_malloc, errors);
+#else
+    int use_utf8 = (Py_UTF8Mode == 1);
+#ifdef MS_WINDOWS
+    use_utf8 |= !Py_LegacyWindowsFSEncodingFlag;
+#endif
+    if (use_utf8) {
+        return _Py_EncodeUTF8Ex(text, str, error_pos, reason,
+                                raw_malloc, errors);
+    }
+
+#ifdef USE_FORCE_ASCII
+    if (force_ascii == -1) {
+        force_ascii = check_force_ascii();
+    }
+
+    if (force_ascii) {
+        return encode_ascii(text, str, error_pos, reason,
+                            raw_malloc, errors);
+    }
+#endif
+
+    return encode_current_locale(text, str, error_pos, reason,
+                                 raw_malloc, errors);
+#endif   /* _Py_FORCE_UTF8_FS_ENCODING */
+}
+
+static char*
+encode_locale(const wchar_t *text, size_t *error_pos,
+              int raw_malloc, int current_locale)
+{
+    char *str;
+    int res = encode_locale_ex(text, &str, error_pos, NULL,
+                               raw_malloc, current_locale,
+                               _Py_ERROR_SURROGATEESCAPE);
+    if (res != -2 && error_pos) {
+        *error_pos = (size_t)-1;
+    }
+    if (res != 0) {
+        return NULL;
+    }
+    return str;
+}
+
+/* Encode a wide character string to the locale encoding with the
+   surrogateescape error handler: surrogate characters in the range
+   U+DC80..U+DCFF are converted to bytes 0x80..0xFF.
+
+   Return a pointer to a newly allocated byte string, use PyMem_Free() to free
+   the memory. Return NULL on encoding or memory allocation error.
+
+   If error_pos is not NULL, *error_pos is set to (size_t)-1 on success, or set
+   to the index of the invalid character on encoding error.
+
+   Use the Py_DecodeLocale() function to decode the bytes string back to a wide
+   character string. */
+char*
+Py_EncodeLocale(const wchar_t *text, size_t *error_pos)
+{
+    return encode_locale(text, error_pos, 0, 0);
+}
+
+
+/* Similar to Py_EncodeLocale(), but result must be freed by PyMem_RawFree()
+   instead of PyMem_Free(). */
+char*
+_Py_EncodeLocaleRaw(const wchar_t *text, size_t *error_pos)
+{
+    return encode_locale(text, error_pos, 1, 0);
+}
+
+
+int
+_Py_EncodeLocaleEx(const wchar_t *text, char **str,
+                   size_t *error_pos, const char **reason,
+                   int current_locale, _Py_error_handler errors)
+{
+    return encode_locale_ex(text, str, error_pos, reason, 1,
+                            current_locale, errors);
+}
+
+
+// Get the current locale encoding name:
+//
+// - Return "utf-8" if _Py_FORCE_UTF8_LOCALE macro is defined (ex: on Android)
+// - Return "utf-8" if the UTF-8 Mode is enabled
+// - On Windows, return the ANSI code page (ex: "cp1250")
+// - Return "utf-8" if nl_langinfo(CODESET) returns an empty string.
+// - Otherwise, return nl_langinfo(CODESET).
+//
+// Return NULL on memory allocation failure.
+//
+// See also config_get_locale_encoding()
+wchar_t*
+_Py_GetLocaleEncoding(void)
+{
+#ifdef _Py_FORCE_UTF8_LOCALE
+    // On Android langinfo.h and CODESET are missing,
+    // and UTF-8 is always used in mbstowcs() and wcstombs().
+    return _PyMem_RawWcsdup(L"utf-8");
+#else
+
+#ifdef MS_WINDOWS
+    wchar_t encoding[23];
+    unsigned int ansi_codepage = GetACP();
+    swprintf(encoding, Py_ARRAY_LENGTH(encoding), L"cp%u", ansi_codepage);
+    encoding[Py_ARRAY_LENGTH(encoding) - 1] = 0;
+    return _PyMem_RawWcsdup(encoding);
+#else
+    const char *encoding = nl_langinfo(CODESET);
+    if (!encoding || encoding[0] == '\0') {
+        // Use UTF-8 if nl_langinfo() returns an empty string. It can happen on
+        // macOS if the LC_CTYPE locale is not supported.
+        return _PyMem_RawWcsdup(L"utf-8");
+    }
+
+    wchar_t *wstr;
+    int res = decode_current_locale(encoding, &wstr, NULL,
+                                    NULL, _Py_ERROR_SURROGATEESCAPE);
+    if (res < 0) {
+        return NULL;
+    }
+    return wstr;
+#endif  // !MS_WINDOWS
+
+#endif  // !_Py_FORCE_UTF8_LOCALE
+}
+
+
+PyObject *
+_Py_GetLocaleEncodingObject(void)
+{
+    wchar_t *encoding = _Py_GetLocaleEncoding();
+    if (encoding == NULL) {
+        PyErr_NoMemory();
+        return NULL;
+    }
+
+    PyObject *str = PyUnicode_FromWideChar(encoding, -1);
+    PyMem_RawFree(encoding);
+    return str;
+}
+
+#ifdef HAVE_NON_UNICODE_WCHAR_T_REPRESENTATION
+
+/* Check whether current locale uses Unicode as internal wchar_t form. */
+int
+_Py_LocaleUsesNonUnicodeWchar(void)
+{
+    /* Oracle Solaris uses non-Unicode internal wchar_t form for
+       non-Unicode locales and hence needs conversion to UTF first. */
+    char* codeset = nl_langinfo(CODESET);
+    if (!codeset) {
+        return 0;
+    }
+    /* 646 refers to ISO/IEC 646 standard that corresponds to ASCII encoding */
+    return (strcmp(codeset, "UTF-8") != 0 && strcmp(codeset, "646") != 0);
+}
+
+static wchar_t *
+_Py_ConvertWCharForm(const wchar_t *source, Py_ssize_t size,
+                     const char *tocode, const char *fromcode)
+{
+    static_assert(sizeof(wchar_t) == 4, "wchar_t must be 32-bit");
+
+    /* Ensure we won't overflow the size. */
+    if (size > (PY_SSIZE_T_MAX / (Py_ssize_t)sizeof(wchar_t))) {
+        PyErr_NoMemory();
+        return NULL;
+    }
+
+    /* the string doesn't have to be NULL terminated */
+    wchar_t* target = PyMem_Malloc(size * sizeof(wchar_t));
+    if (target == NULL) {
+        PyErr_NoMemory();
+        return NULL;
+    }
+
+    iconv_t cd = iconv_open(tocode, fromcode);
+    if (cd == (iconv_t)-1) {
+        PyErr_Format(PyExc_ValueError, "iconv_open() failed");
+        PyMem_Free(target);
+        return NULL;
+    }
+
+    char *inbuf = (char *) source;
+    char *outbuf = (char *) target;
+    size_t inbytesleft = sizeof(wchar_t) * size;
+    size_t outbytesleft = inbytesleft;
+
+    size_t ret = iconv(cd, &inbuf, &inbytesleft, &outbuf, &outbytesleft);
+    if (ret == DECODE_ERROR) {
+        PyErr_Format(PyExc_ValueError, "iconv() failed");
+        PyMem_Free(target);
+        iconv_close(cd);
+        return NULL;
+    }
+
+    iconv_close(cd);
+    return target;
+}
+
+/* Convert a wide character string to the UCS-4 encoded string. This
+   is necessary on systems where internal form of wchar_t are not Unicode
+   code points (e.g. Oracle Solaris).
+
+   Return a pointer to a newly allocated string, use PyMem_Free() to free
+   the memory. Return NULL and raise exception on conversion or memory
+   allocation error. */
+wchar_t *
+_Py_DecodeNonUnicodeWchar(const wchar_t *native, Py_ssize_t size)
+{
+    return _Py_ConvertWCharForm(native, size, "UCS-4-INTERNAL", "wchar_t");
+}
+
+/* Convert a UCS-4 encoded string to native wide character string. This
+   is necessary on systems where internal form of wchar_t are not Unicode
+   code points (e.g. Oracle Solaris).
+
+   The conversion is done in place. This can be done because both wchar_t
+   and UCS-4 use 4-byte encoding, and one wchar_t symbol always correspond
+   to a single UCS-4 symbol and vice versa. (This is true for Oracle Solaris,
+   which is currently the only system using these functions; it doesn't have
+   to be for other systems).
+
+   Return 0 on success. Return -1 and raise exception on conversion
+   or memory allocation error. */
+int
+_Py_EncodeNonUnicodeWchar_InPlace(wchar_t *unicode, Py_ssize_t size)
+{
+    wchar_t* result = _Py_ConvertWCharForm(unicode, size, "wchar_t", "UCS-4-INTERNAL");
+    if (!result) {
+        return -1;
+    }
+    memcpy(unicode, result, size * sizeof(wchar_t));
+    PyMem_Free(result);
+    return 0;
+}
+#endif /* HAVE_NON_UNICODE_WCHAR_T_REPRESENTATION */
+
+#ifdef MS_WINDOWS
+static __int64 secs_between_epochs = 11644473600; /* Seconds between 1.1.1601 and 1.1.1970 */
+
+static void
+FILE_TIME_to_time_t_nsec(FILETIME *in_ptr, time_t *time_out, int* nsec_out)
+{
+    /* XXX endianness. Shouldn't matter, as all Windows implementations are little-endian */
+    /* Cannot simply cast and dereference in_ptr,
+       since it might not be aligned properly */
+    __int64 in;
+    memcpy(&in, in_ptr, sizeof(in));
+    *nsec_out = (int)(in % 10000000) * 100; /* FILETIME is in units of 100 nsec. */
+    *time_out = Py_SAFE_DOWNCAST((in / 10000000) - secs_between_epochs, __int64, time_t);
+}
+
+void
+_Py_time_t_to_FILE_TIME(time_t time_in, int nsec_in, FILETIME *out_ptr)
+{
+    /* XXX endianness */
+    __int64 out;
+    out = time_in + secs_between_epochs;
+    out = out * 10000000 + nsec_in / 100;
+    memcpy(out_ptr, &out, sizeof(out));
+}
+
+/* Below, we *know* that ugo+r is 0444 */
+#if _S_IREAD != 0400
+#error Unsupported C library
+#endif
+static int
+attributes_to_mode(DWORD attr)
+{
+    int m = 0;
+    if (attr & FILE_ATTRIBUTE_DIRECTORY)
+        m |= _S_IFDIR | 0111; /* IFEXEC for user,group,other */
+    else
+        m |= _S_IFREG;
+    if (attr & FILE_ATTRIBUTE_READONLY)
+        m |= 0444;
+    else
+        m |= 0666;
+    return m;
+}
+
+void
+_Py_attribute_data_to_stat(BY_HANDLE_FILE_INFORMATION *info, ULONG reparse_tag,
+                           struct _Py_stat_struct *result)
+{
+    memset(result, 0, sizeof(*result));
+    result->st_mode = attributes_to_mode(info->dwFileAttributes);
+    result->st_size = (((__int64)info->nFileSizeHigh)<<32) + info->nFileSizeLow;
+    result->st_dev = info->dwVolumeSerialNumber;
+    result->st_rdev = result->st_dev;
+    FILE_TIME_to_time_t_nsec(&info->ftCreationTime, &result->st_ctime, &result->st_ctime_nsec);
+    FILE_TIME_to_time_t_nsec(&info->ftLastWriteTime, &result->st_mtime, &result->st_mtime_nsec);
+    FILE_TIME_to_time_t_nsec(&info->ftLastAccessTime, &result->st_atime, &result->st_atime_nsec);
+    result->st_nlink = info->nNumberOfLinks;
+    result->st_ino = (((uint64_t)info->nFileIndexHigh) << 32) + info->nFileIndexLow;
+    /* bpo-37834: Only actual symlinks set the S_IFLNK flag. But lstat() will
+       open other name surrogate reparse points without traversing them. To
+       detect/handle these, check st_file_attributes and st_reparse_tag. */
+    result->st_reparse_tag = reparse_tag;
+    if (info->dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT &&
+        reparse_tag == IO_REPARSE_TAG_SYMLINK) {
+        /* first clear the S_IFMT bits */
+        result->st_mode ^= (result->st_mode & S_IFMT);
+        /* now set the bits that make this a symlink */
+        result->st_mode |= S_IFLNK;
+    }
+    result->st_file_attributes = info->dwFileAttributes;
+}
+#endif
+
+/* Return information about a file.
+
+   On POSIX, use fstat().
+
+   On Windows, use GetFileType() and GetFileInformationByHandle() which support
+   files larger than 2 GiB.  fstat() may fail with EOVERFLOW on files larger
+   than 2 GiB because the file size type is a signed 32-bit integer: see issue
+   #23152.
+
+   On Windows, set the last Windows error and return nonzero on error. On
+   POSIX, set errno and return nonzero on error. Fill status and return 0 on
+   success. */
+int
+_Py_fstat_noraise(int fd, struct _Py_stat_struct *status)
+{
+#ifdef MS_WINDOWS
+    BY_HANDLE_FILE_INFORMATION info;
+    HANDLE h;
+    int type;
+
+    h = _Py_get_osfhandle_noraise(fd);
+
+    if (h == INVALID_HANDLE_VALUE) {
+        /* errno is already set by _get_osfhandle, but we also set
+           the Win32 error for callers who expect that */
+        SetLastError(ERROR_INVALID_HANDLE);
+        return -1;
+    }
+    memset(status, 0, sizeof(*status));
+
+    type = GetFileType(h);
+    if (type == FILE_TYPE_UNKNOWN) {
+        DWORD error = GetLastError();
+        if (error != 0) {
+            errno = winerror_to_errno(error);
+            return -1;
+        }
+        /* else: valid but unknown file */
+    }
+
+    if (type != FILE_TYPE_DISK) {
+        if (type == FILE_TYPE_CHAR)
+            status->st_mode = _S_IFCHR;
+        else if (type == FILE_TYPE_PIPE)
+            status->st_mode = _S_IFIFO;
+        return 0;
+    }
+
+    if (!GetFileInformationByHandle(h, &info)) {
+        /* The Win32 error is already set, but we also set errno for
+           callers who expect it */
+        errno = winerror_to_errno(GetLastError());
+        return -1;
+    }
+
+    _Py_attribute_data_to_stat(&info, 0, status);
+    /* specific to fstat() */
+    status->st_ino = (((uint64_t)info.nFileIndexHigh) << 32) + info.nFileIndexLow;
+    return 0;
+#else
+    return fstat(fd, status);
+#endif
+}
+
+/* Return information about a file.
+
+   On POSIX, use fstat().
+
+   On Windows, use GetFileType() and GetFileInformationByHandle() which support
+   files larger than 2 GiB.  fstat() may fail with EOVERFLOW on files larger
+   than 2 GiB because the file size type is a signed 32-bit integer: see issue
+   #23152.
+
+   Raise an exception and return -1 on error. On Windows, set the last Windows
+   error on error. On POSIX, set errno on error. Fill status and return 0 on
+   success.
+
+   Release the GIL to call GetFileType() and GetFileInformationByHandle(), or
+   to call fstat(). The caller must hold the GIL. */
+int
+_Py_fstat(int fd, struct _Py_stat_struct *status)
+{
+    int res;
+
+    assert(PyGILState_Check());
+
+    Py_BEGIN_ALLOW_THREADS
+    res = _Py_fstat_noraise(fd, status);
+    Py_END_ALLOW_THREADS
+
+    if (res != 0) {
+#ifdef MS_WINDOWS
+        PyErr_SetFromWindowsErr(0);
+#else
+        PyErr_SetFromErrno(PyExc_OSError);
+#endif
+        return -1;
+    }
+    return 0;
+}
+
+/* Like _Py_stat() but with a raw filename. */
+int
+_Py_wstat(const wchar_t* path, struct stat *buf)
+{
+    int err;
+#ifdef MS_WINDOWS
+    struct _stat wstatbuf;
+    err = _wstat(path, &wstatbuf);
+    if (!err) {
+        buf->st_mode = wstatbuf.st_mode;
+    }
+#else
+    char *fname;
+    fname = _Py_EncodeLocaleRaw(path, NULL);
+    if (fname == NULL) {
+        errno = EINVAL;
+        return -1;
+    }
+    err = stat(fname, buf);
+    PyMem_RawFree(fname);
+#endif
+    return err;
+}
+
+
+/* Call _wstat() on Windows, or encode the path to the filesystem encoding and
+   call stat() otherwise. Only fill st_mode attribute on Windows.
+
+   Return 0 on success, -1 on _wstat() / stat() error, -2 if an exception was
+   raised. */
+
+int
+_Py_stat(PyObject *path, struct stat *statbuf)
+{
+#ifdef MS_WINDOWS
+    int err;
+
+#if USE_UNICODE_WCHAR_CACHE
+    const wchar_t *wpath = _PyUnicode_AsUnicode(path);
+#else /* USE_UNICODE_WCHAR_CACHE */
+    wchar_t *wpath = PyUnicode_AsWideCharString(path, NULL);
+#endif /* USE_UNICODE_WCHAR_CACHE */
+    if (wpath == NULL)
+        return -2;
+
+    err = _Py_wstat(wpath, statbuf);
+#if !USE_UNICODE_WCHAR_CACHE
+    PyMem_Free(wpath);
+#endif /* USE_UNICODE_WCHAR_CACHE */
+    return err;
+#else
+    int ret;
+    PyObject *bytes;
+    char *cpath;
+
+    bytes = PyUnicode_EncodeFSDefault(path);
+    if (bytes == NULL)
+        return -2;
+
+    /* check for embedded null bytes */
+    if (PyBytes_AsStringAndSize(bytes, &cpath, NULL) == -1) {
+        Py_DECREF(bytes);
+        return -2;
+    }
+
+    ret = stat(cpath, statbuf);
+    Py_DECREF(bytes);
+    return ret;
+#endif
+}
+
+
+/* This function MUST be kept async-signal-safe on POSIX when raise=0. */
+static int
+get_inheritable(int fd, int raise)
+{
+#ifdef MS_WINDOWS
+    HANDLE handle;
+    DWORD flags;
+
+    handle = _Py_get_osfhandle_noraise(fd);
+    if (handle == INVALID_HANDLE_VALUE) {
+        if (raise)
+            PyErr_SetFromErrno(PyExc_OSError);
+        return -1;
+    }
+
+    if (!GetHandleInformation(handle, &flags)) {
+        if (raise)
+            PyErr_SetFromWindowsErr(0);
+        return -1;
+    }
+
+    return (flags & HANDLE_FLAG_INHERIT);
+#else
+    int flags;
+
+    flags = fcntl(fd, F_GETFD, 0);
+    if (flags == -1) {
+        if (raise)
+            PyErr_SetFromErrno(PyExc_OSError);
+        return -1;
+    }
+    return !(flags & FD_CLOEXEC);
+#endif
+}
+
+/* Get the inheritable flag of the specified file descriptor.
+   Return 1 if the file descriptor can be inherited, 0 if it cannot,
+   raise an exception and return -1 on error. */
+int
+_Py_get_inheritable(int fd)
+{
+    return get_inheritable(fd, 1);
+}
+
+
+/* This function MUST be kept async-signal-safe on POSIX when raise=0. */
+static int
+set_inheritable(int fd, int inheritable, int raise, int *atomic_flag_works)
+{
+#ifdef MS_WINDOWS
+    HANDLE handle;
+    DWORD flags;
+#else
+#if defined(HAVE_SYS_IOCTL_H) && defined(FIOCLEX) && defined(FIONCLEX)
+    static int ioctl_works = -1;
+    int request;
+    int err;
+#endif
+    int flags, new_flags;
+    int res;
+#endif
+
+    /* atomic_flag_works can only be used to make the file descriptor
+       non-inheritable */
+    assert(!(atomic_flag_works != NULL && inheritable));
+
+    if (atomic_flag_works != NULL && !inheritable) {
+        if (*atomic_flag_works == -1) {
+            int isInheritable = get_inheritable(fd, raise);
+            if (isInheritable == -1)
+                return -1;
+            *atomic_flag_works = !isInheritable;
+        }
+
+        if (*atomic_flag_works)
+            return 0;
+    }
+
+#ifdef MS_WINDOWS
+    handle = _Py_get_osfhandle_noraise(fd);
+    if (handle == INVALID_HANDLE_VALUE) {
+        if (raise)
+            PyErr_SetFromErrno(PyExc_OSError);
+        return -1;
+    }
+
+    if (inheritable)
+        flags = HANDLE_FLAG_INHERIT;
+    else
+        flags = 0;
+
+    /* This check can be removed once support for Windows 7 ends. */
+#define CONSOLE_PSEUDOHANDLE(handle) (((ULONG_PTR)(handle) & 0x3) == 0x3 && \
+        GetFileType(handle) == FILE_TYPE_CHAR)
+
+    if (!CONSOLE_PSEUDOHANDLE(handle) &&
+        !SetHandleInformation(handle, HANDLE_FLAG_INHERIT, flags)) {
+        if (raise)
+            PyErr_SetFromWindowsErr(0);
+        return -1;
+    }
+#undef CONSOLE_PSEUDOHANDLE
+    return 0;
+
+#else
+
+#if defined(HAVE_SYS_IOCTL_H) && defined(FIOCLEX) && defined(FIONCLEX)
+    if (ioctl_works != 0 && raise != 0) {
+        /* fast-path: ioctl() only requires one syscall */
+        /* caveat: raise=0 is an indicator that we must be async-signal-safe
+         * thus avoid using ioctl() so we skip the fast-path. */
+        if (inheritable)
+            request = FIONCLEX;
+        else
+            request = FIOCLEX;
+        err = ioctl(fd, request, NULL);
+        if (!err) {
+            ioctl_works = 1;
+            return 0;
+        }
+
+#ifdef O_PATH
+        if (errno == EBADF) {
+            // bpo-44849: On Linux and FreeBSD, ioctl(FIOCLEX) fails with EBADF
+            // on O_PATH file descriptors. Fall through to the fcntl()
+            // implementation.
+        }
+        else
+#endif
+        if (errno != ENOTTY && errno != EACCES) {
+            if (raise)
+                PyErr_SetFromErrno(PyExc_OSError);
+            return -1;
+        }
+        else {
+            /* Issue #22258: Here, ENOTTY means "Inappropriate ioctl for
+               device". The ioctl is declared but not supported by the kernel.
+               Remember that ioctl() doesn't work. It is the case on
+               Illumos-based OS for example.
+
+               Issue #27057: When SELinux policy disallows ioctl it will fail
+               with EACCES. While FIOCLEX is safe operation it may be
+               unavailable because ioctl was denied altogether.
+               This can be the case on Android. */
+            ioctl_works = 0;
+        }
+        /* fallback to fcntl() if ioctl() does not work */
+    }
+#endif
+
+    /* slow-path: fcntl() requires two syscalls */
+    flags = fcntl(fd, F_GETFD);
+    if (flags < 0) {
+        if (raise)
+            PyErr_SetFromErrno(PyExc_OSError);
+        return -1;
+    }
+
+    if (inheritable) {
+        new_flags = flags & ~FD_CLOEXEC;
+    }
+    else {
+        new_flags = flags | FD_CLOEXEC;
+    }
+
+    if (new_flags == flags) {
+        /* FD_CLOEXEC flag already set/cleared: nothing to do */
+        return 0;
+    }
+
+    res = fcntl(fd, F_SETFD, new_flags);
+    if (res < 0) {
+        if (raise)
+            PyErr_SetFromErrno(PyExc_OSError);
+        return -1;
+    }
+    return 0;
+#endif
+}
+
+/* Make the file descriptor non-inheritable.
+   Return 0 on success, set errno and return -1 on error. */
+static int
+make_non_inheritable(int fd)
+{
+    return set_inheritable(fd, 0, 0, NULL);
+}
+
+/* Set the inheritable flag of the specified file descriptor.
+   On success: return 0, on error: raise an exception and return -1.
+
+   If atomic_flag_works is not NULL:
+
+    * if *atomic_flag_works==-1, check if the inheritable is set on the file
+      descriptor: if yes, set *atomic_flag_works to 1, otherwise set to 0 and
+      set the inheritable flag
+    * if *atomic_flag_works==1: do nothing
+    * if *atomic_flag_works==0: set inheritable flag to False
+
+   Set atomic_flag_works to NULL if no atomic flag was used to create the
+   file descriptor.
+
+   atomic_flag_works can only be used to make a file descriptor
+   non-inheritable: atomic_flag_works must be NULL if inheritable=1. */
+int
+_Py_set_inheritable(int fd, int inheritable, int *atomic_flag_works)
+{
+    return set_inheritable(fd, inheritable, 1, atomic_flag_works);
+}
+
+/* Same as _Py_set_inheritable() but on error, set errno and
+   don't raise an exception.
+   This function is async-signal-safe. */
+int
+_Py_set_inheritable_async_safe(int fd, int inheritable, int *atomic_flag_works)
+{
+    return set_inheritable(fd, inheritable, 0, atomic_flag_works);
+}
+
+static int
+_Py_open_impl(const char *pathname, int flags, int gil_held)
+{
+    int fd;
+    int async_err = 0;
+#ifndef MS_WINDOWS
+    int *atomic_flag_works;
+#endif
+
+#ifdef MS_WINDOWS
+    flags |= O_NOINHERIT;
+#elif defined(O_CLOEXEC)
+    atomic_flag_works = &_Py_open_cloexec_works;
+    flags |= O_CLOEXEC;
+#else
+    atomic_flag_works = NULL;
+#endif
+
+    if (gil_held) {
+        PyObject *pathname_obj = PyUnicode_DecodeFSDefault(pathname);
+        if (pathname_obj == NULL) {
+            return -1;
+        }
+        if (PySys_Audit("open", "OOi", pathname_obj, Py_None, flags) < 0) {
+            Py_DECREF(pathname_obj);
+            return -1;
+        }
+
+        do {
+            Py_BEGIN_ALLOW_THREADS
+            fd = open(pathname, flags);
+            Py_END_ALLOW_THREADS
+        } while (fd < 0
+                 && errno == EINTR && !(async_err = PyErr_CheckSignals()));
+        if (async_err) {
+            Py_DECREF(pathname_obj);
+            return -1;
+        }
+        if (fd < 0) {
+            PyErr_SetFromErrnoWithFilenameObjects(PyExc_OSError, pathname_obj, NULL);
+            Py_DECREF(pathname_obj);
+            return -1;
+        }
+        Py_DECREF(pathname_obj);
+    }
+    else {
+        fd = open(pathname, flags);
+        if (fd < 0)
+            return -1;
+    }
+
+#ifndef MS_WINDOWS
+    if (set_inheritable(fd, 0, gil_held, atomic_flag_works) < 0) {
+        close(fd);
+        return -1;
+    }
+#endif
+
+    return fd;
+}
+
+/* Open a file with the specified flags (wrapper to open() function).
+   Return a file descriptor on success. Raise an exception and return -1 on
+   error.
+
+   The file descriptor is created non-inheritable.
+
+   When interrupted by a signal (open() fails with EINTR), retry the syscall,
+   except if the Python signal handler raises an exception.
+
+   Release the GIL to call open(). The caller must hold the GIL. */
+int
+_Py_open(const char *pathname, int flags)
+{
+    /* _Py_open() must be called with the GIL held. */
+    assert(PyGILState_Check());
+    return _Py_open_impl(pathname, flags, 1);
+}
+
+/* Open a file with the specified flags (wrapper to open() function).
+   Return a file descriptor on success. Set errno and return -1 on error.
+
+   The file descriptor is created non-inheritable.
+
+   If interrupted by a signal, fail with EINTR. */
+int
+_Py_open_noraise(const char *pathname, int flags)
+{
+    return _Py_open_impl(pathname, flags, 0);
+}
+
+/* Open a file. Use _wfopen() on Windows, encode the path to the locale
+   encoding and use fopen() otherwise.
+
+   The file descriptor is created non-inheritable.
+
+   If interrupted by a signal, fail with EINTR. */
+FILE *
+_Py_wfopen(const wchar_t *path, const wchar_t *mode)
+{
+    FILE *f;
+    if (PySys_Audit("open", "uui", path, mode, 0) < 0) {
+        return NULL;
+    }
+#ifndef MS_WINDOWS
+    char *cpath;
+    char cmode[10];
+    size_t r;
+    r = wcstombs(cmode, mode, 10);
+    if (r == DECODE_ERROR || r >= 10) {
+        errno = EINVAL;
+        return NULL;
+    }
+    cpath = _Py_EncodeLocaleRaw(path, NULL);
+    if (cpath == NULL) {
+        return NULL;
+    }
+    f = fopen(cpath, cmode);
+    PyMem_RawFree(cpath);
+#else
+    f = _wfopen(path, mode);
+#endif
+    if (f == NULL)
+        return NULL;
+    if (make_non_inheritable(fileno(f)) < 0) {
+        fclose(f);
+        return NULL;
+    }
+    return f;
+}
+
+
+/* Open a file. Call _wfopen() on Windows, or encode the path to the filesystem
+   encoding and call fopen() otherwise.
+
+   Return the new file object on success. Raise an exception and return NULL
+   on error.
+
+   The file descriptor is created non-inheritable.
+
+   When interrupted by a signal (open() fails with EINTR), retry the syscall,
+   except if the Python signal handler raises an exception.
+
+   Release the GIL to call _wfopen() or fopen(). The caller must hold
+   the GIL. */
+FILE*
+_Py_fopen_obj(PyObject *path, const char *mode)
+{
+    FILE *f;
+    int async_err = 0;
+#ifdef MS_WINDOWS
+    wchar_t wmode[10];
+    int usize;
+
+    assert(PyGILState_Check());
+
+    if (PySys_Audit("open", "Osi", path, mode, 0) < 0) {
+        return NULL;
+    }
+    if (!PyUnicode_Check(path)) {
+        PyErr_Format(PyExc_TypeError,
+                     "str file path expected under Windows, got %R",
+                     Py_TYPE(path));
+        return NULL;
+    }
+#if USE_UNICODE_WCHAR_CACHE
+    const wchar_t *wpath = _PyUnicode_AsUnicode(path);
+#else /* USE_UNICODE_WCHAR_CACHE */
+    wchar_t *wpath = PyUnicode_AsWideCharString(path, NULL);
+#endif /* USE_UNICODE_WCHAR_CACHE */
+    if (wpath == NULL)
+        return NULL;
+
+    usize = MultiByteToWideChar(CP_ACP, 0, mode, -1,
+                                wmode, Py_ARRAY_LENGTH(wmode));
+    if (usize == 0) {
+        PyErr_SetFromWindowsErr(0);
+#if !USE_UNICODE_WCHAR_CACHE
+        PyMem_Free(wpath);
+#endif /* USE_UNICODE_WCHAR_CACHE */
+        return NULL;
+    }
+
+    do {
+        Py_BEGIN_ALLOW_THREADS
+        f = _wfopen(wpath, wmode);
+        Py_END_ALLOW_THREADS
+    } while (f == NULL
+             && errno == EINTR && !(async_err = PyErr_CheckSignals()));
+#if !USE_UNICODE_WCHAR_CACHE
+    PyMem_Free(wpath);
+#endif /* USE_UNICODE_WCHAR_CACHE */
+#else
+    PyObject *bytes;
+    const char *path_bytes;
+
+    assert(PyGILState_Check());
+
+    if (!PyUnicode_FSConverter(path, &bytes))
+        return NULL;
+    path_bytes = PyBytes_AS_STRING(bytes);
+
+    if (PySys_Audit("open", "Osi", path, mode, 0) < 0) {
+        Py_DECREF(bytes);
+        return NULL;
+    }
+
+    do {
+        Py_BEGIN_ALLOW_THREADS
+        f = fopen(path_bytes, mode);
+        Py_END_ALLOW_THREADS
+    } while (f == NULL
+             && errno == EINTR && !(async_err = PyErr_CheckSignals()));
+
+    Py_DECREF(bytes);
+#endif
+    if (async_err)
+        return NULL;
+
+    if (f == NULL) {
+        PyErr_SetFromErrnoWithFilenameObject(PyExc_OSError, path);
+        return NULL;
+    }
+
+    if (set_inheritable(fileno(f), 0, 1, NULL) < 0) {
+        fclose(f);
+        return NULL;
+    }
+    return f;
+}
+
+/* Read count bytes from fd into buf.
+
+   On success, return the number of read bytes, it can be lower than count.
+   If the current file offset is at or past the end of file, no bytes are read,
+   and read() returns zero.
+
+   On error, raise an exception, set errno and return -1.
+
+   When interrupted by a signal (read() fails with EINTR), retry the syscall.
+   If the Python signal handler raises an exception, the function returns -1
+   (the syscall is not retried).
+
+   Release the GIL to call read(). The caller must hold the GIL. */
+Py_ssize_t
+_Py_read(int fd, void *buf, size_t count)
+{
+    Py_ssize_t n;
+    int err;
+    int async_err = 0;
+
+    assert(PyGILState_Check());
+
+    /* _Py_read() must not be called with an exception set, otherwise the
+     * caller may think that read() was interrupted by a signal and the signal
+     * handler raised an exception. */
+    assert(!PyErr_Occurred());
+
+    if (count > _PY_READ_MAX) {
+        count = _PY_READ_MAX;
+    }
+
+    _Py_BEGIN_SUPPRESS_IPH
+    do {
+        Py_BEGIN_ALLOW_THREADS
+        errno = 0;
+#ifdef MS_WINDOWS
+        n = read(fd, buf, (int)count);
+#else
+        n = read(fd, buf, count);
+#endif
+        /* save/restore errno because PyErr_CheckSignals()
+         * and PyErr_SetFromErrno() can modify it */
+        err = errno;
+        Py_END_ALLOW_THREADS
+    } while (n < 0 && err == EINTR &&
+            !(async_err = PyErr_CheckSignals()));
+    _Py_END_SUPPRESS_IPH
+
+    if (async_err) {
+        /* read() was interrupted by a signal (failed with EINTR)
+         * and the Python signal handler raised an exception */
+        errno = err;
+        assert(errno == EINTR && PyErr_Occurred());
+        return -1;
+    }
+    if (n < 0) {
+        PyErr_SetFromErrno(PyExc_OSError);
+        errno = err;
+        return -1;
+    }
+
+    return n;
+}
+
+static Py_ssize_t
+_Py_write_impl(int fd, const void *buf, size_t count, int gil_held)
+{
+    Py_ssize_t n;
+    int err;
+    int async_err = 0;
+
+    _Py_BEGIN_SUPPRESS_IPH
+#ifdef MS_WINDOWS
+    if (count > 32767) {
+        /* Issue #11395: the Windows console returns an error (12: not
+           enough space error) on writing into stdout if stdout mode is
+           binary and the length is greater than 66,000 bytes (or less,
+           depending on heap usage). */
+        if (gil_held) {
+            Py_BEGIN_ALLOW_THREADS
+            if (isatty(fd)) {
+                count = 32767;
+            }
+            Py_END_ALLOW_THREADS
+        } else {
+            if (isatty(fd)) {
+                count = 32767;
+            }
+        }
+    }
+#endif
+    if (count > _PY_WRITE_MAX) {
+        count = _PY_WRITE_MAX;
+    }
+
+    if (gil_held) {
+        do {
+            Py_BEGIN_ALLOW_THREADS
+            errno = 0;
+#ifdef MS_WINDOWS
+            n = write(fd, buf, (int)count);
+#else
+            n = write(fd, buf, count);
+#endif
+            /* save/restore errno because PyErr_CheckSignals()
+             * and PyErr_SetFromErrno() can modify it */
+            err = errno;
+            Py_END_ALLOW_THREADS
+        } while (n < 0 && err == EINTR &&
+                !(async_err = PyErr_CheckSignals()));
+    }
+    else {
+        do {
+            errno = 0;
+#ifdef MS_WINDOWS
+            n = write(fd, buf, (int)count);
+#else
+            n = write(fd, buf, count);
+#endif
+            err = errno;
+        } while (n < 0 && err == EINTR);
+    }
+    _Py_END_SUPPRESS_IPH
+
+    if (async_err) {
+        /* write() was interrupted by a signal (failed with EINTR)
+           and the Python signal handler raised an exception (if gil_held is
+           nonzero). */
+        errno = err;
+        assert(errno == EINTR && (!gil_held || PyErr_Occurred()));
+        return -1;
+    }
+    if (n < 0) {
+        if (gil_held)
+            PyErr_SetFromErrno(PyExc_OSError);
+        errno = err;
+        return -1;
+    }
+
+    return n;
+}
+
+/* Write count bytes of buf into fd.
+
+   On success, return the number of written bytes, it can be lower than count
+   including 0. On error, raise an exception, set errno and return -1.
+
+   When interrupted by a signal (write() fails with EINTR), retry the syscall.
+   If the Python signal handler raises an exception, the function returns -1
+   (the syscall is not retried).
+
+   Release the GIL to call write(). The caller must hold the GIL. */
+Py_ssize_t
+_Py_write(int fd, const void *buf, size_t count)
+{
+    assert(PyGILState_Check());
+
+    /* _Py_write() must not be called with an exception set, otherwise the
+     * caller may think that write() was interrupted by a signal and the signal
+     * handler raised an exception. */
+    assert(!PyErr_Occurred());
+
+    return _Py_write_impl(fd, buf, count, 1);
+}
+
+/* Write count bytes of buf into fd.
+ *
+ * On success, return the number of written bytes, it can be lower than count
+ * including 0. On error, set errno and return -1.
+ *
+ * When interrupted by a signal (write() fails with EINTR), retry the syscall
+ * without calling the Python signal handler. */
+Py_ssize_t
+_Py_write_noraise(int fd, const void *buf, size_t count)
+{
+    return _Py_write_impl(fd, buf, count, 0);
+}
+
+#ifdef HAVE_READLINK
+
+/* Read value of symbolic link. Encode the path to the locale encoding, decode
+   the result from the locale encoding.
+
+   Return -1 on encoding error, on readlink() error, if the internal buffer is
+   too short, on decoding error, or if 'buf' is too short. */
+int
+_Py_wreadlink(const wchar_t *path, wchar_t *buf, size_t buflen)
+{
+    char *cpath;
+    char cbuf[MAXPATHLEN];
+    size_t cbuf_len = Py_ARRAY_LENGTH(cbuf);
+    wchar_t *wbuf;
+    Py_ssize_t res;
+    size_t r1;
+
+    cpath = _Py_EncodeLocaleRaw(path, NULL);
+    if (cpath == NULL) {
+        errno = EINVAL;
+        return -1;
+    }
+    res = readlink(cpath, cbuf, cbuf_len);
+    PyMem_RawFree(cpath);
+    if (res == -1) {
+        return -1;
+    }
+    if ((size_t)res == cbuf_len) {
+        errno = EINVAL;
+        return -1;
+    }
+    cbuf[res] = '\0'; /* buf will be null terminated */
+    wbuf = Py_DecodeLocale(cbuf, &r1);
+    if (wbuf == NULL) {
+        errno = EINVAL;
+        return -1;
+    }
+    /* wbuf must have space to store the trailing NUL character */
+    if (buflen <= r1) {
+        PyMem_RawFree(wbuf);
+        errno = EINVAL;
+        return -1;
+    }
+    wcsncpy(buf, wbuf, buflen);
+    PyMem_RawFree(wbuf);
+    return (int)r1;
+}
+#endif
+
+#ifdef HAVE_REALPATH
+
+/* Return the canonicalized absolute pathname. Encode path to the locale
+   encoding, decode the result from the locale encoding.
+
+   Return NULL on encoding error, realpath() error, decoding error
+   or if 'resolved_path' is too short. */
+wchar_t*
+_Py_wrealpath(const wchar_t *path,
+              wchar_t *resolved_path, size_t resolved_path_len)
+{
+    char *cpath;
+    char cresolved_path[MAXPATHLEN];
+    wchar_t *wresolved_path;
+    char *res;
+    size_t r;
+    cpath = _Py_EncodeLocaleRaw(path, NULL);
+    if (cpath == NULL) {
+        errno = EINVAL;
+        return NULL;
+    }
+    res = realpath(cpath, cresolved_path);
+    PyMem_RawFree(cpath);
+    if (res == NULL)
+        return NULL;
+
+    wresolved_path = Py_DecodeLocale(cresolved_path, &r);
+    if (wresolved_path == NULL) {
+        errno = EINVAL;
+        return NULL;
+    }
+    /* wresolved_path must have space to store the trailing NUL character */
+    if (resolved_path_len <= r) {
+        PyMem_RawFree(wresolved_path);
+        errno = EINVAL;
+        return NULL;
+    }
+    wcsncpy(resolved_path, wresolved_path, resolved_path_len);
+    PyMem_RawFree(wresolved_path);
+    return resolved_path;
+}
+#endif
+
+
+int
+_Py_isabs(const wchar_t *path)
+{
+#ifdef MS_WINDOWS
+    const wchar_t *tail;
+    HRESULT hr = PathCchSkipRoot(path, &tail);
+    if (FAILED(hr) || path == tail) {
+        return 0;
+    }
+    if (tail == &path[1] && (path[0] == SEP || path[0] == ALTSEP)) {
+        // Exclude paths with leading SEP
+        return 0;
+    }
+    if (tail == &path[2] && path[1] == L':') {
+        // Exclude drive-relative paths (e.g. C:filename.ext)
+        return 0;
+    }
+    return 1;
+#else
+    return (path[0] == SEP);
+#endif
+}
+
+
+/* Get an absolute path.
+   On error (ex: fail to get the current directory), return -1.
+   On memory allocation failure, set *abspath_p to NULL and return 0.
+   On success, return a newly allocated to *abspath_p to and return 0.
+   The string must be freed by PyMem_RawFree(). */
+int
+_Py_abspath(const wchar_t *path, wchar_t **abspath_p)
+{
+    if (path[0] == '\0' || !wcscmp(path, L".")) {
+        wchar_t cwd[MAXPATHLEN + 1];
+        cwd[Py_ARRAY_LENGTH(cwd) - 1] = 0;
+        if (!_Py_wgetcwd(cwd, Py_ARRAY_LENGTH(cwd) - 1)) {
+            /* unable to get the current directory */
+            return -1;
+        }
+        *abspath_p = _PyMem_RawWcsdup(cwd);
+        return 0;
+    }
+
+    if (_Py_isabs(path)) {
+        *abspath_p = _PyMem_RawWcsdup(path);
+        return 0;
+    }
+
+#ifdef MS_WINDOWS
+    return _PyOS_getfullpathname(path, abspath_p);
+#else
+    wchar_t cwd[MAXPATHLEN + 1];
+    cwd[Py_ARRAY_LENGTH(cwd) - 1] = 0;
+    if (!_Py_wgetcwd(cwd, Py_ARRAY_LENGTH(cwd) - 1)) {
+        /* unable to get the current directory */
+        return -1;
+    }
+
+    size_t cwd_len = wcslen(cwd);
+    size_t path_len = wcslen(path);
+    size_t len = cwd_len + 1 + path_len + 1;
+    if (len <= (size_t)PY_SSIZE_T_MAX / sizeof(wchar_t)) {
+        *abspath_p = PyMem_RawMalloc(len * sizeof(wchar_t));
+    }
+    else {
+        *abspath_p = NULL;
+    }
+    if (*abspath_p == NULL) {
+        return 0;
+    }
+
+    wchar_t *abspath = *abspath_p;
+    memcpy(abspath, cwd, cwd_len * sizeof(wchar_t));
+    abspath += cwd_len;
+
+    *abspath = (wchar_t)SEP;
+    abspath++;
+
+    memcpy(abspath, path, path_len * sizeof(wchar_t));
+    abspath += path_len;
+
+    *abspath = 0;
+    return 0;
+#endif
+}
+
+
+// The caller must ensure "buffer" is big enough.
+static int
+join_relfile(wchar_t *buffer, size_t bufsize,
+             const wchar_t *dirname, const wchar_t *relfile)
+{
+#ifdef MS_WINDOWS
+    if (FAILED(PathCchCombineEx(buffer, bufsize, dirname, relfile,
+        PATHCCH_ALLOW_LONG_PATHS))) {
+        return -1;
+    }
+#else
+    assert(!_Py_isabs(relfile));
+    size_t dirlen = wcslen(dirname);
+    size_t rellen = wcslen(relfile);
+    size_t maxlen = bufsize - 1;
+    if (maxlen > MAXPATHLEN || dirlen >= maxlen || rellen >= maxlen - dirlen) {
+        return -1;
+    }
+    if (dirlen == 0) {
+        // We do not add a leading separator.
+        wcscpy(buffer, relfile);
+    }
+    else {
+        if (dirname != buffer) {
+            wcscpy(buffer, dirname);
+        }
+        size_t relstart = dirlen;
+        if (dirlen > 1 && dirname[dirlen - 1] != SEP) {
+            buffer[dirlen] = SEP;
+            relstart += 1;
+        }
+        wcscpy(&buffer[relstart], relfile);
+    }
+#endif
+    return 0;
+}
+
+/* Join the two paths together, like os.path.join().  Return NULL
+   if memory could not be allocated.  The caller is responsible
+   for calling PyMem_RawFree() on the result. */
+wchar_t *
+_Py_join_relfile(const wchar_t *dirname, const wchar_t *relfile)
+{
+    assert(dirname != NULL && relfile != NULL);
+#ifndef MS_WINDOWS
+    assert(!_Py_isabs(relfile));
+#endif
+    size_t maxlen = wcslen(dirname) + 1 + wcslen(relfile);
+    size_t bufsize = maxlen + 1;
+    wchar_t *filename = PyMem_RawMalloc(bufsize * sizeof(wchar_t));
+    if (filename == NULL) {
+        return NULL;
+    }
+    assert(wcslen(dirname) < MAXPATHLEN);
+    assert(wcslen(relfile) < MAXPATHLEN - wcslen(dirname));
+    if (join_relfile(filename, bufsize, dirname, relfile) < 0) {
+        PyMem_RawFree(filename);
+        return NULL;
+    }
+    return filename;
+}
+
+/* Join the two paths together, like os.path.join().
+     dirname: the target buffer with the dirname already in place,
+              including trailing NUL
+     relfile: this must be a relative path
+     bufsize: total allocated size of the buffer
+   Return -1 if anything is wrong with the path lengths. */
+int
+_Py_add_relfile(wchar_t *dirname, const wchar_t *relfile, size_t bufsize)
+{
+    assert(dirname != NULL && relfile != NULL);
+    assert(bufsize > 0);
+    return join_relfile(dirname, bufsize, dirname, relfile);
+}
+
+
+size_t
+_Py_find_basename(const wchar_t *filename)
+{
+    for (size_t i = wcslen(filename); i > 0; --i) {
+        if (filename[i] == SEP) {
+            return i + 1;
+        }
+    }
+    return 0;
+}
+
+/* In-place path normalisation. Returns the start of the normalized
+   path, which will be within the original buffer. Guaranteed to not
+   make the path longer, and will not fail. 'size' is the length of
+   the path, if known. If -1, the first null character will be assumed
+   to be the end of the path. 'normsize' will be set to contain the
+   length of the resulting normalized path. */
+wchar_t *
+_Py_normpath_and_size(wchar_t *path, Py_ssize_t size, Py_ssize_t *normsize)
+{
+    assert(path != NULL);
+    if ((size < 0 && !path[0]) || size == 0) {
+        *normsize = 0;
+        return path;
+    }
+    wchar_t *pEnd = size >= 0 ? &path[size] : NULL;
+    wchar_t *p1 = path;     // sequentially scanned address in the path
+    wchar_t *p2 = path;     // destination of a scanned character to be ljusted
+    wchar_t *minP2 = path;  // the beginning of the destination range
+    wchar_t lastC = L'\0';  // the last ljusted character, p2[-1] in most cases
+
+#define IS_END(x) (pEnd ? (x) == pEnd : !*(x))
+#ifdef ALTSEP
+#define IS_SEP(x) (*(x) == SEP || *(x) == ALTSEP)
+#else
+#define IS_SEP(x) (*(x) == SEP)
+#endif
+#define SEP_OR_END(x) (IS_SEP(x) || IS_END(x))
+
+    // Skip leading '.\'
+    if (p1[0] == L'.' && IS_SEP(&p1[1])) {
+        path = &path[2];
+        while (IS_SEP(path) && !IS_END(path)) {
+            path++;
+        }
+        p1 = p2 = minP2 = path;
+        lastC = SEP;
+    }
+#ifdef MS_WINDOWS
+    // Skip past drive segment and update minP2
+    else if (p1[0] && p1[1] == L':') {
+        *p2++ = *p1++;
+        *p2++ = *p1++;
+        minP2 = p2;
+        lastC = L':';
+    }
+    // Skip past all \\-prefixed paths, including \\?\, \\.\,
+    // and network paths, including the first segment.
+    else if (IS_SEP(&p1[0]) && IS_SEP(&p1[1])) {
+        int sepCount = 2;
+        *p2++ = SEP;
+        *p2++ = SEP;
+        p1 += 2;
+        for (; !IS_END(p1) && sepCount; ++p1) {
+            if (IS_SEP(p1)) {
+                --sepCount;
+                *p2++ = lastC = SEP;
+            } else {
+                *p2++ = lastC = *p1;
+            }
+        }
+        minP2 = p2 - 1;
+    }
+#else
+    // Skip past two leading SEPs
+    else if (IS_SEP(&p1[0]) && IS_SEP(&p1[1]) && !IS_SEP(&p1[2])) {
+        *p2++ = *p1++;
+        *p2++ = *p1++;
+        minP2 = p2 - 1;  // Absolute path has SEP at minP2
+        lastC = SEP;
+    }
+#endif /* MS_WINDOWS */
+
+    /* if pEnd is specified, check that. Else, check for null terminator */
+    for (; !IS_END(p1); ++p1) {
+        wchar_t c = *p1;
+#ifdef ALTSEP
+        if (c == ALTSEP) {
+            c = SEP;
+        }
+#endif
+        if (lastC == SEP) {
+            if (c == L'.') {
+                int sep_at_1 = SEP_OR_END(&p1[1]);
+                int sep_at_2 = !sep_at_1 && SEP_OR_END(&p1[2]);
+                if (sep_at_2 && p1[1] == L'.') {
+                    wchar_t *p3 = p2;
+                    while (p3 != minP2 && *--p3 == SEP) { }
+                    while (p3 != minP2 && *(p3 - 1) != SEP) { --p3; }
+                    if (p2 == minP2
+                        || (p3[0] == L'.' && p3[1] == L'.' && IS_SEP(&p3[2])))
+                    {
+                        // Previous segment is also ../, so append instead.
+                        // Relative path does not absorb ../ at minP2 as well.
+                        *p2++ = L'.';
+                        *p2++ = L'.';
+                        lastC = L'.';
+                    } else if (p3[0] == SEP) {
+                        // Absolute path, so absorb segment
+                        p2 = p3 + 1;
+                    } else {
+                        p2 = p3;
+                    }
+                    p1 += 1;
+                } else if (sep_at_1) {
+                } else {
+                    *p2++ = lastC = c;
+                }
+            } else if (c == SEP) {
+            } else {
+                *p2++ = lastC = c;
+            }
+        } else {
+            *p2++ = lastC = c;
+        }
+    }
+    *p2 = L'\0';
+    if (p2 != minP2) {
+        while (--p2 != minP2 && *p2 == SEP) {
+            *p2 = L'\0';
+        }
+    } else {
+        --p2;
+    }
+    *normsize = p2 - path + 1;
+#undef SEP_OR_END
+#undef IS_SEP
+#undef IS_END
+    return path;
+}
+
+/* In-place path normalisation. Returns the start of the normalized
+   path, which will be within the original buffer. Guaranteed to not
+   make the path longer, and will not fail. 'size' is the length of
+   the path, if known. If -1, the first null character will be assumed
+   to be the end of the path. */
+wchar_t *
+_Py_normpath(wchar_t *path, Py_ssize_t size)
+{
+    Py_ssize_t norm_length;
+    return _Py_normpath_and_size(path, size, &norm_length);
+}
+
+
+/* Get the current directory. buflen is the buffer size in wide characters
+   including the null character. Decode the path from the locale encoding.
+
+   Return NULL on getcwd() error, on decoding error, or if 'buf' is
+   too short. */
+wchar_t*
+_Py_wgetcwd(wchar_t *buf, size_t buflen)
+{
+#ifdef MS_WINDOWS
+    int ibuflen = (int)Py_MIN(buflen, INT_MAX);
+    return _wgetcwd(buf, ibuflen);
+#else
+    char fname[MAXPATHLEN];
+    wchar_t *wname;
+    size_t len;
+
+    if (getcwd(fname, Py_ARRAY_LENGTH(fname)) == NULL)
+        return NULL;
+    wname = Py_DecodeLocale(fname, &len);
+    if (wname == NULL)
+        return NULL;
+    /* wname must have space to store the trailing NUL character */
+    if (buflen <= len) {
+        PyMem_RawFree(wname);
+        return NULL;
+    }
+    wcsncpy(buf, wname, buflen);
+    PyMem_RawFree(wname);
+    return buf;
+#endif
+}
+
+/* Duplicate a file descriptor. The new file descriptor is created as
+   non-inheritable. Return a new file descriptor on success, raise an OSError
+   exception and return -1 on error.
+
+   The GIL is released to call dup(). The caller must hold the GIL. */
+int
+_Py_dup(int fd)
+{
+#ifdef MS_WINDOWS
+    HANDLE handle;
+#endif
+
+    assert(PyGILState_Check());
+
+#ifdef MS_WINDOWS
+    handle = _Py_get_osfhandle(fd);
+    if (handle == INVALID_HANDLE_VALUE)
+        return -1;
+
+    Py_BEGIN_ALLOW_THREADS
+    _Py_BEGIN_SUPPRESS_IPH
+    fd = dup(fd);
+    _Py_END_SUPPRESS_IPH
+    Py_END_ALLOW_THREADS
+    if (fd < 0) {
+        PyErr_SetFromErrno(PyExc_OSError);
+        return -1;
+    }
+
+    if (_Py_set_inheritable(fd, 0, NULL) < 0) {
+        _Py_BEGIN_SUPPRESS_IPH
+        close(fd);
+        _Py_END_SUPPRESS_IPH
+        return -1;
+    }
+#elif defined(HAVE_FCNTL_H) && defined(F_DUPFD_CLOEXEC)
+    Py_BEGIN_ALLOW_THREADS
+    _Py_BEGIN_SUPPRESS_IPH
+    fd = fcntl(fd, F_DUPFD_CLOEXEC, 0);
+    _Py_END_SUPPRESS_IPH
+    Py_END_ALLOW_THREADS
+    if (fd < 0) {
+        PyErr_SetFromErrno(PyExc_OSError);
+        return -1;
+    }
+
+#elif HAVE_DUP
+    Py_BEGIN_ALLOW_THREADS
+    _Py_BEGIN_SUPPRESS_IPH
+    fd = dup(fd);
+    _Py_END_SUPPRESS_IPH
+    Py_END_ALLOW_THREADS
+    if (fd < 0) {
+        PyErr_SetFromErrno(PyExc_OSError);
+        return -1;
+    }
+
+    if (_Py_set_inheritable(fd, 0, NULL) < 0) {
+        _Py_BEGIN_SUPPRESS_IPH
+        close(fd);
+        _Py_END_SUPPRESS_IPH
+        return -1;
+    }
+#else
+    errno = ENOTSUP;
+    PyErr_SetFromErrno(PyExc_OSError);
+    return -1;
+#endif
+    return fd;
+}
+
+#ifndef MS_WINDOWS
+/* Get the blocking mode of the file descriptor.
+   Return 0 if the O_NONBLOCK flag is set, 1 if the flag is cleared,
+   raise an exception and return -1 on error. */
+int
+_Py_get_blocking(int fd)
+{
+    int flags;
+    _Py_BEGIN_SUPPRESS_IPH
+    flags = fcntl(fd, F_GETFL, 0);
+    _Py_END_SUPPRESS_IPH
+    if (flags < 0) {
+        PyErr_SetFromErrno(PyExc_OSError);
+        return -1;
+    }
+
+    return !(flags & O_NONBLOCK);
+}
+
+/* Set the blocking mode of the specified file descriptor.
+
+   Set the O_NONBLOCK flag if blocking is False, clear the O_NONBLOCK flag
+   otherwise.
+
+   Return 0 on success, raise an exception and return -1 on error. */
+int
+_Py_set_blocking(int fd, int blocking)
+{
+/* bpo-41462: On VxWorks, ioctl(FIONBIO) only works on sockets.
+   Use fcntl() instead. */
+#if defined(HAVE_SYS_IOCTL_H) && defined(FIONBIO) && !defined(__VXWORKS__)
+    int arg = !blocking;
+    if (ioctl(fd, FIONBIO, &arg) < 0)
+        goto error;
+#else
+    int flags, res;
+
+    _Py_BEGIN_SUPPRESS_IPH
+    flags = fcntl(fd, F_GETFL, 0);
+    if (flags >= 0) {
+        if (blocking)
+            flags = flags & (~O_NONBLOCK);
+        else
+            flags = flags | O_NONBLOCK;
+
+        res = fcntl(fd, F_SETFL, flags);
+    } else {
+        res = -1;
+    }
+    _Py_END_SUPPRESS_IPH
+
+    if (res < 0)
+        goto error;
+#endif
+    return 0;
+
+error:
+    PyErr_SetFromErrno(PyExc_OSError);
+    return -1;
+}
+#else   /* MS_WINDOWS */
+void*
+_Py_get_osfhandle_noraise(int fd)
+{
+    void *handle;
+    _Py_BEGIN_SUPPRESS_IPH
+    handle = (void*)_get_osfhandle(fd);
+    _Py_END_SUPPRESS_IPH
+    return handle;
+}
+
+void*
+_Py_get_osfhandle(int fd)
+{
+    void *handle = _Py_get_osfhandle_noraise(fd);
+    if (handle == INVALID_HANDLE_VALUE)
+        PyErr_SetFromErrno(PyExc_OSError);
+
+    return handle;
+}
+
+int
+_Py_open_osfhandle_noraise(void *handle, int flags)
+{
+    int fd;
+    _Py_BEGIN_SUPPRESS_IPH
+    fd = _open_osfhandle((intptr_t)handle, flags);
+    _Py_END_SUPPRESS_IPH
+    return fd;
+}
+
+int
+_Py_open_osfhandle(void *handle, int flags)
+{
+    int fd = _Py_open_osfhandle_noraise(handle, flags);
+    if (fd == -1)
+        PyErr_SetFromErrno(PyExc_OSError);
+
+    return fd;
+}
+#endif  /* MS_WINDOWS */
+
+int
+_Py_GetLocaleconvNumeric(struct lconv *lc,
+                         PyObject **decimal_point, PyObject **thousands_sep)
+{
+    assert(decimal_point != NULL);
+    assert(thousands_sep != NULL);
+
+#ifndef MS_WINDOWS
+    int change_locale = 0;
+    if ((strlen(lc->decimal_point) > 1 || ((unsigned char)lc->decimal_point[0]) > 127)) {
+        change_locale = 1;
+    }
+    if ((strlen(lc->thousands_sep) > 1 || ((unsigned char)lc->thousands_sep[0]) > 127)) {
+        change_locale = 1;
+    }
+
+    /* Keep a copy of the LC_CTYPE locale */
+    char *oldloc = NULL, *loc = NULL;
+    if (change_locale) {
+        oldloc = setlocale(LC_CTYPE, NULL);
+        if (!oldloc) {
+            PyErr_SetString(PyExc_RuntimeWarning,
+                            "failed to get LC_CTYPE locale");
+            return -1;
+        }
+
+        oldloc = _PyMem_Strdup(oldloc);
+        if (!oldloc) {
+            PyErr_NoMemory();
+            return -1;
+        }
+
+        loc = setlocale(LC_NUMERIC, NULL);
+        if (loc != NULL && strcmp(loc, oldloc) == 0) {
+            loc = NULL;
+        }
+
+        if (loc != NULL) {
+            /* Only set the locale temporarily the LC_CTYPE locale
+               if LC_NUMERIC locale is different than LC_CTYPE locale and
+               decimal_point and/or thousands_sep are non-ASCII or longer than
+               1 byte */
+            setlocale(LC_CTYPE, loc);
+        }
+    }
+
+#define GET_LOCALE_STRING(ATTR) PyUnicode_DecodeLocale(lc->ATTR, NULL)
+#else /* MS_WINDOWS */
+/* Use _W_* fields of Windows strcut lconv */
+#define GET_LOCALE_STRING(ATTR) PyUnicode_FromWideChar(lc->_W_ ## ATTR, -1)
+#endif /* MS_WINDOWS */
+
+    int res = -1;
+
+    *decimal_point = GET_LOCALE_STRING(decimal_point);
+    if (*decimal_point == NULL) {
+        goto done;
+    }
+
+    *thousands_sep = GET_LOCALE_STRING(thousands_sep);
+    if (*thousands_sep == NULL) {
+        goto done;
+    }
+
+    res = 0;
+
+done:
+#ifndef MS_WINDOWS
+    if (loc != NULL) {
+        setlocale(LC_CTYPE, oldloc);
+    }
+    PyMem_Free(oldloc);
+#endif
+    return res;
+
+#undef GET_LOCALE_STRING
+}
+
+/* Our selection logic for which function to use is as follows:
+ * 1. If close_range(2) is available, always prefer that; it's better for
+ *    contiguous ranges like this than fdwalk(3) which entails iterating over
+ *    the entire fd space and simply doing nothing for those outside the range.
+ * 2. If closefrom(2) is available, we'll attempt to use that next if we're
+ *    closing up to sysconf(_SC_OPEN_MAX).
+ * 2a. Fallback to fdwalk(3) if we're not closing up to sysconf(_SC_OPEN_MAX),
+ *    as that will be more performant if the range happens to have any chunk of
+ *    non-opened fd in the middle.
+ * 2b. If fdwalk(3) isn't available, just do a plain close(2) loop.
+ */
+#ifdef __FreeBSD__
+#  define USE_CLOSEFROM
+#endif /* __FreeBSD__ */
+
+#ifdef HAVE_FDWALK
+#  define USE_FDWALK
+#endif /* HAVE_FDWALK */
+
+#ifdef USE_FDWALK
+static int
+_fdwalk_close_func(void *lohi, int fd)
+{
+    int lo = ((int *)lohi)[0];
+    int hi = ((int *)lohi)[1];
+
+    if (fd >= hi) {
+        return 1;
+    }
+    else if (fd >= lo) {
+        /* Ignore errors */
+        (void)close(fd);
+    }
+    return 0;
+}
+#endif /* USE_FDWALK */
+
+/* Closes all file descriptors in [first, last], ignoring errors. */
+void
+_Py_closerange(int first, int last)
+{
+    first = Py_MAX(first, 0);
+    _Py_BEGIN_SUPPRESS_IPH
+#ifdef HAVE_CLOSE_RANGE
+    if (close_range(first, last, 0) == 0) {
+        /* close_range() ignores errors when it closes file descriptors.
+         * Possible reasons of an error return are lack of kernel support
+         * or denial of the underlying syscall by a seccomp sandbox on Linux.
+         * Fallback to other methods in case of any error. */
+    }
+    else
+#endif /* HAVE_CLOSE_RANGE */
+#ifdef USE_CLOSEFROM
+    if (last >= sysconf(_SC_OPEN_MAX)) {
+        /* Any errors encountered while closing file descriptors are ignored */
+        closefrom(first);
+    }
+    else
+#endif /* USE_CLOSEFROM */
+#ifdef USE_FDWALK
+    {
+        int lohi[2];
+        lohi[0] = first;
+        lohi[1] = last + 1;
+        fdwalk(_fdwalk_close_func, lohi);
+    }
+#else
+    {
+        for (int i = first; i <= last; i++) {
+            /* Ignore errors */
+            (void)close(i);
+        }
+    }
+#endif /* USE_FDWALK */
+    _Py_END_SUPPRESS_IPH
+}