Create fileutils.c/.h

* _Py_fopen() and _Py_stat() come from Python/import.c
 * (_Py)_wrealpath() comes from Python/sysmodule.c
 * _Py_char2wchar(), _Py_wchar2char() and _Py_wfopen() come from Modules/main.c
 * (_Py)_wstat(), (_Py)_wgetcwd(), _Py_wreadlink() come from Modules/getpath.c

Include/Python.h

@@ -122,6 +122,7 @@
 #include "pystrtod.h"
 #include "pystrcmp.h"
 #include "dtoa.h"
+#include "fileutils.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -130,17 +131,6 @@ extern "C" {
 /* _Py_Mangle is defined in compile.c */
 PyAPI_FUNC(PyObject*) _Py_Mangle(PyObject *p, PyObject *name);
 
-/* These functions live in main.c */
-PyAPI_FUNC(wchar_t *) _Py_char2wchar(char *);
-PyAPI_FUNC(char*) _Py_wchar2char(const wchar_t *text);
-PyAPI_FUNC(FILE *) _Py_wfopen(const wchar_t *path, const wchar_t *mode);
-
-/* These functions live in import.c */
-PyAPI_FUNC(FILE*) _Py_fopen(PyObject *unicode, const char *mode);
-#ifdef HAVE_STAT
-int _Py_stat(PyObject *unicode, struct stat *statbuf);
-#endif
-
 #ifdef __cplusplus
 }
 #endif

Include/fileutils.h

@@ -0,0 +1,55 @@
+#ifndef Py_FILEUTILS_H
+#define Py_FILEUTILS_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+PyAPI_FUNC(wchar_t *) _Py_char2wchar(
+    char *arg);
+
+PyAPI_FUNC(char*) _Py_wchar2char(
+    const wchar_t *text);
+
+#if defined(MS_WINDOWS) || defined(HAVE_STAT)
+PyAPI_FUNC(int) _Py_wstat(
+    const wchar_t* path,
+    struct stat *buf);
+#endif
+
+#ifdef HAVE_STAT
+PyAPI_FUNC(int) _Py_stat(
+    PyObject *unicode,
+    struct stat *statbuf);
+#endif
+
+PyAPI_FUNC(FILE *) _Py_wfopen(
+    const wchar_t *path,
+    const wchar_t *mode);
+
+PyAPI_FUNC(FILE*) _Py_fopen(
+    PyObject *unicode,
+    const char *mode);
+
+#ifdef HAVE_READLINK
+PyAPI_FUNC(int) _Py_wreadlink(
+    const wchar_t *path,
+    wchar_t *buf,
+    size_t bufsiz);
+#endif
+
+#ifdef HAVE_REALPATH
+PyAPI_FUNC(wchar_t*) _Py_wrealpath(
+    const wchar_t *path,
+    wchar_t *resolved_path);
+#endif
+
+PyAPI_FUNC(wchar_t*) _Py_wgetcwd(
+    wchar_t *buf,
+    size_t size);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* !Py_FILEUTILS_H */

Makefile.pre.in

@@ -325,6 +325,7 @@ PYTHON_OBJS=	\
 		Python/pystrtod.o \
 		Python/dtoa.o \
 		Python/formatter_unicode.o \
+		Python/fileutils.o \
 		Python/$(DYNLOADFILE) \
 		$(LIBOBJS) \
 		$(MACHDEP_OBJS) \
@@ -665,6 +666,7 @@ PYTHON_HEADERS= \
 		Include/errcode.h \
 		Include/eval.h \
 		Include/fileobject.h \
+		Include/fileutils.h \
 		Include/floatobject.h \
 		Include/frameobject.h \
 		Include/funcobject.h \

Modules/getpath.c

@@ -136,78 +136,6 @@ static wchar_t progpath[MAXPATHLEN+1];
 static wchar_t *module_search_path = NULL;
 static wchar_t *lib_python = L"lib/python" VERSION;
 
-/* In principle, this should use HAVE__WSTAT, and _wstat
-   should be detected by autoconf. However, no current
-   POSIX system provides that function, so testing for
-   it is pointless.
-   Not sure whether the MS_WINDOWS guards are necessary:
-   perhaps for cygwin/mingw builds?
-*/
-#ifndef MS_WINDOWS
-static int
-_wstat(const wchar_t* path, struct stat *buf)
-{
-    int err;
-    char *fname;
-    fname = _Py_wchar2char(path);
-    if (fname == NULL) {
-        errno = EINVAL;
-        return -1;
-    }
-    err = stat(fname, buf);
-    PyMem_Free(fname);
-    return err;
-}
-#endif
-
-#ifndef MS_WINDOWS
-static wchar_t*
-_wgetcwd(wchar_t *buf, size_t size)
-{
-    char fname[PATH_MAX];
-    if (getcwd(fname, PATH_MAX) == NULL)
-        return NULL;
-    if (mbstowcs(buf, fname, size) >= size) {
-        errno = ERANGE;
-        return NULL;
-    }
-    return buf;
-}
-#endif
-
-#ifdef HAVE_READLINK
-int
-_Py_wreadlink(const wchar_t *path, wchar_t *buf, size_t bufsiz)
-{
-    char *cpath;
-    char cbuf[PATH_MAX];
-    int res;
-    size_t r1;
-
-    cpath = _Py_wchar2char(path);
-    if (cpath == NULL) {
-        errno = EINVAL;
-        return -1;
-    }
-    res = (int)readlink(cpath, cbuf, PATH_MAX);
-    PyMem_Free(cpath);
-    if (res == -1)
-        return -1;
-    if (res == PATH_MAX) {
-        errno = EINVAL;
-        return -1;
-    }
-    cbuf[res] = '\0'; /* buf will be null terminated */
-    r1 = mbstowcs(buf, cbuf, bufsiz);
-    if (r1 == -1) {
-        errno = EINVAL;
-        return -1;
-    }
-    return (int)r1;
-
-}
-#endif
-
 static void
 reduce(wchar_t *dir)
 {
@@ -217,12 +145,11 @@ reduce(wchar_t *dir)
     dir[i] = '\0';
 }
 
-
 static int
 isfile(wchar_t *filename)          /* Is file, not directory */
 {
     struct stat buf;
-    if (_wstat(filename, &buf) != 0)
+    if (_Py_wstat(filename, &buf) != 0)
         return 0;
     if (!S_ISREG(buf.st_mode))
         return 0;
@@ -250,7 +177,7 @@ static int
 isxfile(wchar_t *filename)         /* Is executable file */
 {
     struct stat buf;
-    if (_wstat(filename, &buf) != 0)
+    if (_Py_wstat(filename, &buf) != 0)
         return 0;
     if (!S_ISREG(buf.st_mode))
         return 0;
@@ -264,7 +191,7 @@ static int
 isdir(wchar_t *filename)                   /* Is directory */
 {
     struct stat buf;
-    if (_wstat(filename, &buf) != 0)
+    if (_Py_wstat(filename, &buf) != 0)
         return 0;
     if (!S_ISDIR(buf.st_mode))
         return 0;
@@ -309,7 +236,7 @@ copy_absolute(wchar_t *path, wchar_t *p)
     if (p[0] == SEP)
         wcscpy(path, p);
     else {
-        _wgetcwd(path, MAXPATHLEN);
+        _Py_wgetcwd(path, MAXPATHLEN);
         if (p[0] == '.' && p[1] == SEP)
             p += 2;
         joinpath(path, p);

Modules/main.c

@@ -104,31 +104,6 @@ static char *usage_5 =
 #endif
 ;
 
-FILE *
-_Py_wfopen(const wchar_t *path, const wchar_t *mode)
-{
-#ifndef MS_WINDOWS
-    FILE *f;
-    char *cpath;
-    char cmode[10];
-    size_t r;
-    r = wcstombs(cmode, mode, 10);
-    if (r == (size_t)-1 || r >= 10) {
-        errno = EINVAL;
-        return NULL;
-    }
-    cpath = _Py_wchar2char(path);
-    if (cpath == NULL)
-        return NULL;
-    f = fopen(cpath, cmode);
-    PyMem_Free(cpath);
-    return f;
-#else
-    return _wfopen(path, mode);
-#endif
-}
-
-
 static int
 usage(int exitcode, wchar_t* program)
 {
@@ -756,189 +731,6 @@ Py_GetArgcArgv(int *argc, wchar_t ***argv)
     *argv = orig_argv;
 }
 
-
-/* Encode a (wide) character string to the locale encoding with the
-   surrogateescape error handler (characters in range U+DC80..U+DCFF are
-   converted to bytes 0x80..0xFF).
-
-   This function is the reverse of _Py_char2wchar().
-
-   Return a pointer to a newly allocated byte string (use PyMem_Free() to free
-   the memory), or NULL on error (conversion error or memory error). */
-char*
-_Py_wchar2char(const wchar_t *text)
-{
-    const size_t len = wcslen(text);
-    char *result = NULL, *bytes = NULL;
-    size_t i, size, converted;
-    wchar_t c, buf[2];
-
-    /* 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) {
-                /* 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 == (size_t)-1) {
-                    if (result != NULL)
-                        PyMem_Free(result);
-                    return NULL;
-                }
-                if (bytes != NULL) {
-                    bytes += converted;
-                    size -= converted;
-                }
-                else
-                    size += converted;
-            }
-        }
-        if (result != NULL) {
-            *bytes = 0;
-            break;
-        }
-
-        size += 1; /* nul byte at the end */
-        result = PyMem_Malloc(size);
-        if (result == NULL)
-            return NULL;
-        bytes = result;
-    }
-    return result;
-}
-
-
-/* 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.
-
-   Use _Py_wchar2char() to encode the character string back to a byte string.
-
-   Return a pointer to a newly allocated (wide) character string (use
-   PyMem_Free() to free the memory), or NULL on error (conversion error or
-   memory error). */
-wchar_t*
-_Py_char2wchar(char* arg)
-{
-    wchar_t *res;
-#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.
-     */
-    size_t argsize = strlen(arg);
-#else
-    size_t argsize = mbstowcs(NULL, arg, 0);
-#endif
-    size_t count;
-    unsigned char *in;
-    wchar_t *out;
-#ifdef HAVE_MBRTOWC
-    mbstate_t mbs;
-#endif
-    if (argsize != (size_t)-1) {
-        res = (wchar_t *)PyMem_Malloc((argsize+1)*sizeof(wchar_t));
-        if (!res)
-            goto oom;
-        count = mbstowcs(res, arg, argsize+1);
-        if (count != (size_t)-1) {
-            wchar_t *tmp;
-            /* Only use the result if it contains no
-               surrogate characters. */
-            for (tmp = res; *tmp != 0 &&
-                         (*tmp < 0xd800 || *tmp > 0xdfff); tmp++)
-                ;
-            if (*tmp == 0)
-                return res;
-        }
-        PyMem_Free(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;
-    res = (wchar_t*)PyMem_Malloc(argsize*sizeof(wchar_t));
-    if (!res) goto oom;
-    in = (unsigned char*)arg;
-    out = res;
-    memset(&mbs, 0, sizeof mbs);
-    while (argsize) {
-        size_t converted = mbrtowc(out, (char*)in, argsize, &mbs);
-        if (converted == 0)
-            /* Reached end of string; null char stored. */
-            break;
-        if (converted == (size_t)-2) {
-            /* 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. */
-            fprintf(stderr, "unexpected mbrtowc result -2\n");
-            return NULL;
-        }
-        if (converted == (size_t)-1) {
-            /* Conversion error. Escape as UTF-8b, and start over
-               in the initial shift state. */
-            *out++ = 0xdc00 + *in++;
-            argsize--;
-            memset(&mbs, 0, sizeof mbs);
-            continue;
-        }
-        if (*out >= 0xd800 && *out <= 0xdfff) {
-            /* Surrogate character.  Escape the original
-               byte sequence with surrogateescape. */
-            argsize -= converted;
-            while (converted--)
-                *out++ = 0xdc00 + *in++;
-            continue;
-        }
-        /* successfully converted some bytes */
-        in += converted;
-        argsize -= converted;
-        out++;
-    }
-#else
-    /* 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. */
-    res = PyMem_Malloc((strlen(arg)+1)*sizeof(wchar_t));
-    if (!res) goto oom;
-    in = (unsigned char*)arg;
-    out = res;
-    while(*in)
-        if(*in < 128)
-            *out++ = *in++;
-        else
-            *out++ = 0xdc00 + *in++;
-    *out = 0;
-#endif
-    return res;
-oom:
-    fprintf(stderr, "out of memory\n");
-    return NULL;
-}
-
 #ifdef __cplusplus
 }
 #endif

PCbuild/pythoncore.vcproj

@@ -722,6 +722,10 @@
 				RelativePath="..\Include\fileobject.h"
 				>
 			</File>
+			<File
+				RelativePath="..\Include\fileutils.h"
+				>
+			</File>
 			<File
 				RelativePath="..\Include\floatobject.h"
 				>
@@ -1686,6 +1690,10 @@
 				RelativePath="..\Python\errors.c"
 				>
 			</File>
+			<File
+				RelativePath="..\Python\fileutils.c"
+				>
+			</File>
 			<File
 				RelativePath="..\Python\formatter_unicode.c"
 				>

Python/fileutils.c

@@ -0,0 +1,758 @@
+#include "Python.h"
+
+#ifdef HAVE_STAT
+
+/* 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.
+
+   Use _Py_wchar2char() to encode the character string back to a byte string.
+
+   Return a pointer to a newly allocated (wide) character string (use
+   PyMem_Free() to free the memory), or NULL on error (conversion error or
+   memory error). */
+wchar_t*
+_Py_char2wchar(char* arg)
+{
+    wchar_t *res;
+#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.
+     */
+    size_t argsize = strlen(arg);
+#else
+    size_t argsize = mbstowcs(NULL, arg, 0);
+#endif
+    size_t count;
+    unsigned char *in;
+    wchar_t *out;
+#ifdef HAVE_MBRTOWC
+    mbstate_t mbs;
+#endif
+    if (argsize != (size_t)-1) {
+        res = (wchar_t *)PyMem_Malloc((argsize+1)*sizeof(wchar_t));
+        if (!res)
+            goto oom;
+        count = mbstowcs(res, arg, argsize+1);
+        if (count != (size_t)-1) {
+            wchar_t *tmp;
+            /* Only use the result if it contains no
+               surrogate characters. */
+            for (tmp = res; *tmp != 0 &&
+                         (*tmp < 0xd800 || *tmp > 0xdfff); tmp++)
+                ;
+            if (*tmp == 0)
+                return res;
+        }
+        PyMem_Free(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;
+    res = (wchar_t*)PyMem_Malloc(argsize*sizeof(wchar_t));
+    if (!res) goto oom;
+    in = (unsigned char*)arg;
+    out = res;
+    memset(&mbs, 0, sizeof mbs);
+    while (argsize) {
+        size_t converted = mbrtowc(out, (char*)in, argsize, &mbs);
+        if (converted == 0)
+            /* Reached end of string; null char stored. */
+            break;
+        if (converted == (size_t)-2) {
+            /* 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. */
+            fprintf(stderr, "unexpected mbrtowc result -2\n");
+            return NULL;
+        }
+        if (converted == (size_t)-1) {
+            /* Conversion error. Escape as UTF-8b, and start over
+               in the initial shift state. */
+            *out++ = 0xdc00 + *in++;
+            argsize--;
+            memset(&mbs, 0, sizeof mbs);
+            continue;
+        }
+        if (*out >= 0xd800 && *out <= 0xdfff) {
+            /* Surrogate character.  Escape the original
+               byte sequence with surrogateescape. */
+            argsize -= converted;
+            while (converted--)
+                *out++ = 0xdc00 + *in++;
+            continue;
+        }
+        /* successfully converted some bytes */
+        in += converted;
+        argsize -= converted;
+        out++;
+    }
+#else
+    /* 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. */
+    res = PyMem_Malloc((strlen(arg)+1)*sizeof(wchar_t));
+    if (!res) goto oom;
+    in = (unsigned char*)arg;
+    out = res;
+    while(*in)
+        if(*in < 128)
+            *out++ = *in++;
+        else
+            *out++ = 0xdc00 + *in++;
+    *out = 0;
+#endif
+    return res;
+oom:
+    fprintf(stderr, "out of memory\n");
+    return NULL;
+}
+
+/* Encode a (wide) character string to the locale encoding with the
+   surrogateescape error handler (characters in range U+DC80..U+DCFF are
+   converted to bytes 0x80..0xFF).
+
+   This function is the reverse of _Py_char2wchar().
+
+   Return a pointer to a newly allocated byte string (use PyMem_Free() to free
+   the memory), or NULL on error (conversion error or memory error). */
+char*
+_Py_wchar2char(const wchar_t *text)
+{
+    const size_t len = wcslen(text);
+    char *result = NULL, *bytes = NULL;
+    size_t i, size, converted;
+    wchar_t c, buf[2];
+
+    /* 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) {
+                /* 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 == (size_t)-1) {
+                    if (result != NULL)
+                        PyMem_Free(result);
+                    return NULL;
+                }
+                if (bytes != NULL) {
+                    bytes += converted;
+                    size -= converted;
+                }
+                else
+                    size += converted;
+            }
+        }
+        if (result != NULL) {
+            *bytes = 0;
+            break;
+        }
+
+        size += 1; /* nul byte at the end */
+        result = PyMem_Malloc(size);
+        if (result == NULL)
+            return NULL;
+        bytes = result;
+    }
+    return result;
+}
+
+#if defined(MS_WINDOWS) || defined(HAVE_STAT)
+int
+_Py_wstat(const wchar_t* path, struct stat *buf)
+{
+/* In principle, this should use HAVE__WSTAT, and _wstat
+   should be detected by autoconf. However, no current
+   POSIX system provides that function, so testing for
+   it is pointless.
+   Not sure whether the MS_WINDOWS guards are necessary:
+   perhaps for cygwin/mingw builds?
+*/
+#ifdef MS_WINDOWS
+    return _wstat(path, buf);
+#else
+    int err;
+    char *fname;
+    fname = _Py_wchar2char(path);
+    if (fname == NULL) {
+        errno = EINVAL;
+        return -1;
+    }
+    err = stat(fname, buf);
+    PyMem_Free(fname);
+    return err;
+#endif
+}
+#endif
+
+/* Call _wstat() on Windows, or stat() otherwise. Only fill st_mode
+   attribute on Windows. Return 0 on success, -1 on stat error or (if
+   PyErr_Occurred()) unicode error. */
+
+int
+_Py_stat(PyObject *unicode, struct stat *statbuf)
+{
+#ifdef MS_WINDOWS
+    wchar_t *path;
+    int err;
+    struct _stat wstatbuf;
+
+    path = PyUnicode_AsWideCharString(unicode, NULL);
+    if (path == NULL)
+        return -1;
+    err = _wstat(path, &wstatbuf);
+    PyMem_Free(path);
+    if (!err)
+        statbuf->st_mode = wstatbuf.st_mode;
+    return err;
+#else
+    int ret;
+    PyObject *bytes = PyUnicode_EncodeFSDefault(unicode);
+    if (bytes == NULL)
+        return -1;
+    ret = stat(PyBytes_AS_STRING(bytes), statbuf);
+    Py_DECREF(bytes);
+    return ret;
+#endif
+}
+
+FILE *
+_Py_wfopen(const wchar_t *path, const wchar_t *mode)
+{
+#ifndef MS_WINDOWS
+    FILE *f;
+    char *cpath;
+    char cmode[10];
+    size_t r;
+    r = wcstombs(cmode, mode, 10);
+    if (r == (size_t)-1 || r >= 10) {
+        errno = EINVAL;
+        return NULL;
+    }
+    cpath = _Py_wchar2char(path);
+    if (cpath == NULL)
+        return NULL;
+    f = fopen(cpath, cmode);
+    PyMem_Free(cpath);
+    return f;
+#else
+    return _wfopen(path, mode);
+#endif
+}
+
+/* Call _wfopen() on Windows, or fopen() otherwise. Return the new file
+   object on success, or NULL if the file cannot be open or (if
+   PyErr_Occurred()) on unicode error */
+
+FILE*
+_Py_fopen(PyObject *unicode, const char *mode)
+{
+#ifdef MS_WINDOWS
+    wchar_t *path;
+    wchar_t wmode[10];
+    int usize;
+    FILE *f;
+
+    usize = MultiByteToWideChar(CP_ACP, 0, mode, -1, wmode, sizeof(wmode));
+    if (usize == 0)
+        return NULL;
+
+    path = PyUnicode_AsWideCharString(unicode, NULL);
+    if (path == NULL)
+        return NULL;
+    f = _wfopen(path, wmode);
+    PyMem_Free(path);
+    return f;
+#else
+    FILE *f;
+    PyObject *bytes = PyUnicode_EncodeFSDefault(unicode);
+    if (bytes == NULL)
+        return NULL;
+    f = fopen(PyBytes_AS_STRING(bytes), mode);
+    Py_DECREF(bytes);
+    return f;
+#endif
+}
+
+#ifdef HAVE_READLINK
+int
+_Py_wreadlink(const wchar_t *path, wchar_t *buf, size_t bufsiz)
+{
+    char *cpath;
+    char cbuf[PATH_MAX];
+    int res;
+    size_t r1;
+
+    cpath = _Py_wchar2char(path);
+    if (cpath == NULL) {
+        errno = EINVAL;
+        return -1;
+    }
+    res = (int)readlink(cpath, cbuf, PATH_MAX);
+    PyMem_Free(cpath);
+    if (res == -1)
+        return -1;
+    if (res == PATH_MAX) {
+        errno = EINVAL;
+        return -1;
+    }
+    cbuf[res] = '\0'; /* buf will be null terminated */
+    r1 = mbstowcs(buf, cbuf, bufsiz);
+    if (r1 == -1) {
+        errno = EINVAL;
+        return -1;
+    }
+    return (int)r1;
+}
+#endif
+
+#ifdef HAVE_REALPATH
+wchar_t*
+_Py_wrealpath(const wchar_t *path, wchar_t *resolved_path)
+{
+    char *cpath;
+    char cresolved_path[PATH_MAX];
+    char *res;
+    size_t r;
+    cpath = _Py_wchar2char(path);
+    if (cpath == NULL) {
+        errno = EINVAL;
+        return NULL;
+    }
+    res = realpath(cpath, cresolved_path);
+    PyMem_Free(cpath);
+    if (res == NULL)
+        return NULL;
+    r = mbstowcs(resolved_path, cresolved_path, PATH_MAX);
+    if (r == (size_t)-1 || r >= PATH_MAX) {
+        errno = EINVAL;
+        return NULL;
+    }
+    return resolved_path;
+}
+#endif
+
+wchar_t*
+_Py_wgetcwd(wchar_t *buf, size_t size)
+{
+#ifdef MS_WINDOWS
+    return _wgetcwd(buf, size);
+#else
+    char fname[PATH_MAX];
+    if (getcwd(fname, PATH_MAX) == NULL)
+        return NULL;
+    if (mbstowcs(buf, fname, size) >= size) {
+        errno = ERANGE;
+        return NULL;
+    }
+    return buf;
+#endif
+}
+
+#endif
+
+#include "Python.h"
+
+#ifdef HAVE_STAT
+
+/* 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.
+
+   Use _Py_wchar2char() to encode the character string back to a byte string.
+
+   Return a pointer to a newly allocated (wide) character string (use
+   PyMem_Free() to free the memory), or NULL on error (conversion error or
+   memory error). */
+wchar_t*
+_Py_char2wchar(char* arg)
+{
+    wchar_t *res;
+#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.
+     */
+    size_t argsize = strlen(arg);
+#else
+    size_t argsize = mbstowcs(NULL, arg, 0);
+#endif
+    size_t count;
+    unsigned char *in;
+    wchar_t *out;
+#ifdef HAVE_MBRTOWC
+    mbstate_t mbs;
+#endif
+    if (argsize != (size_t)-1) {
+        res = (wchar_t *)PyMem_Malloc((argsize+1)*sizeof(wchar_t));
+        if (!res)
+            goto oom;
+        count = mbstowcs(res, arg, argsize+1);
+        if (count != (size_t)-1) {
+            wchar_t *tmp;
+            /* Only use the result if it contains no
+               surrogate characters. */
+            for (tmp = res; *tmp != 0 &&
+                         (*tmp < 0xd800 || *tmp > 0xdfff); tmp++)
+                ;
+            if (*tmp == 0)
+                return res;
+        }
+        PyMem_Free(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;
+    res = (wchar_t*)PyMem_Malloc(argsize*sizeof(wchar_t));
+    if (!res) goto oom;
+    in = (unsigned char*)arg;
+    out = res;
+    memset(&mbs, 0, sizeof mbs);
+    while (argsize) {
+        size_t converted = mbrtowc(out, (char*)in, argsize, &mbs);
+        if (converted == 0)
+            /* Reached end of string; null char stored. */
+            break;
+        if (converted == (size_t)-2) {
+            /* 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. */
+            fprintf(stderr, "unexpected mbrtowc result -2\n");
+            return NULL;
+        }
+        if (converted == (size_t)-1) {
+            /* Conversion error. Escape as UTF-8b, and start over
+               in the initial shift state. */
+            *out++ = 0xdc00 + *in++;
+            argsize--;
+            memset(&mbs, 0, sizeof mbs);
+            continue;
+        }
+        if (*out >= 0xd800 && *out <= 0xdfff) {
+            /* Surrogate character.  Escape the original
+               byte sequence with surrogateescape. */
+            argsize -= converted;
+            while (converted--)
+                *out++ = 0xdc00 + *in++;
+            continue;
+        }
+        /* successfully converted some bytes */
+        in += converted;
+        argsize -= converted;
+        out++;
+    }
+#else
+    /* 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. */
+    res = PyMem_Malloc((strlen(arg)+1)*sizeof(wchar_t));
+    if (!res) goto oom;
+    in = (unsigned char*)arg;
+    out = res;
+    while(*in)
+        if(*in < 128)
+            *out++ = *in++;
+        else
+            *out++ = 0xdc00 + *in++;
+    *out = 0;
+#endif
+    return res;
+oom:
+    fprintf(stderr, "out of memory\n");
+    return NULL;
+}
+
+/* Encode a (wide) character string to the locale encoding with the
+   surrogateescape error handler (characters in range U+DC80..U+DCFF are
+   converted to bytes 0x80..0xFF).
+
+   This function is the reverse of _Py_char2wchar().
+
+   Return a pointer to a newly allocated byte string (use PyMem_Free() to free
+   the memory), or NULL on error (conversion error or memory error). */
+char*
+_Py_wchar2char(const wchar_t *text)
+{
+    const size_t len = wcslen(text);
+    char *result = NULL, *bytes = NULL;
+    size_t i, size, converted;
+    wchar_t c, buf[2];
+
+    /* 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) {
+                /* 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 == (size_t)-1) {
+                    if (result != NULL)
+                        PyMem_Free(result);
+                    return NULL;
+                }
+                if (bytes != NULL) {
+                    bytes += converted;
+                    size -= converted;
+                }
+                else
+                    size += converted;
+            }
+        }
+        if (result != NULL) {
+            *bytes = 0;
+            break;
+        }
+
+        size += 1; /* nul byte at the end */
+        result = PyMem_Malloc(size);
+        if (result == NULL)
+            return NULL;
+        bytes = result;
+    }
+    return result;
+}
+
+#if defined(MS_WINDOWS) || defined(HAVE_STAT)
+int
+_Py_wstat(const wchar_t* path, struct stat *buf)
+{
+/* In principle, this should use HAVE__WSTAT, and _wstat
+   should be detected by autoconf. However, no current
+   POSIX system provides that function, so testing for
+   it is pointless.
+   Not sure whether the MS_WINDOWS guards are necessary:
+   perhaps for cygwin/mingw builds?
+*/
+#ifdef MS_WINDOWS
+    return _wstat(path, buf);
+#else
+    int err;
+    char *fname;
+    fname = _Py_wchar2char(path);
+    if (fname == NULL) {
+        errno = EINVAL;
+        return -1;
+    }
+    err = stat(fname, buf);
+    PyMem_Free(fname);
+    return err;
+#endif
+}
+#endif
+
+/* Call _wstat() on Windows, or stat() otherwise. Only fill st_mode
+   attribute on Windows. Return 0 on success, -1 on stat error or (if
+   PyErr_Occurred()) unicode error. */
+
+int
+_Py_stat(PyObject *unicode, struct stat *statbuf)
+{
+#ifdef MS_WINDOWS
+    wchar_t *path;
+    int err;
+    struct _stat wstatbuf;
+
+    path = PyUnicode_AsWideCharString(unicode, NULL);
+    if (path == NULL)
+        return -1;
+    err = _wstat(path, &wstatbuf);
+    PyMem_Free(path);
+    if (!err)
+        statbuf->st_mode = wstatbuf.st_mode;
+    return err;
+#else
+    int ret;
+    PyObject *bytes = PyUnicode_EncodeFSDefault(unicode);
+    if (bytes == NULL)
+        return -1;
+    ret = stat(PyBytes_AS_STRING(bytes), statbuf);
+    Py_DECREF(bytes);
+    return ret;
+#endif
+}
+
+FILE *
+_Py_wfopen(const wchar_t *path, const wchar_t *mode)
+{
+#ifndef MS_WINDOWS
+    FILE *f;
+    char *cpath;
+    char cmode[10];
+    size_t r;
+    r = wcstombs(cmode, mode, 10);
+    if (r == (size_t)-1 || r >= 10) {
+        errno = EINVAL;
+        return NULL;
+    }
+    cpath = _Py_wchar2char(path);
+    if (cpath == NULL)
+        return NULL;
+    f = fopen(cpath, cmode);
+    PyMem_Free(cpath);
+    return f;
+#else
+    return _wfopen(path, mode);
+#endif
+}
+
+/* Call _wfopen() on Windows, or fopen() otherwise. Return the new file
+   object on success, or NULL if the file cannot be open or (if
+   PyErr_Occurred()) on unicode error */
+
+FILE*
+_Py_fopen(PyObject *unicode, const char *mode)
+{
+#ifdef MS_WINDOWS
+    wchar_t *path;
+    wchar_t wmode[10];
+    int usize;
+    FILE *f;
+
+    usize = MultiByteToWideChar(CP_ACP, 0, mode, -1, wmode, sizeof(wmode));
+    if (usize == 0)
+        return NULL;
+
+    path = PyUnicode_AsWideCharString(unicode, NULL);
+    if (path == NULL)
+        return NULL;
+    f = _wfopen(path, wmode);
+    PyMem_Free(path);
+    return f;
+#else
+    FILE *f;
+    PyObject *bytes = PyUnicode_EncodeFSDefault(unicode);
+    if (bytes == NULL)
+        return NULL;
+    f = fopen(PyBytes_AS_STRING(bytes), mode);
+    Py_DECREF(bytes);
+    return f;
+#endif
+}
+
+#ifdef HAVE_READLINK
+int
+_Py_wreadlink(const wchar_t *path, wchar_t *buf, size_t bufsiz)
+{
+    char *cpath;
+    char cbuf[PATH_MAX];
+    int res;
+    size_t r1;
+
+    cpath = _Py_wchar2char(path);
+    if (cpath == NULL) {
+        errno = EINVAL;
+        return -1;
+    }
+    res = (int)readlink(cpath, cbuf, PATH_MAX);
+    PyMem_Free(cpath);
+    if (res == -1)
+        return -1;
+    if (res == PATH_MAX) {
+        errno = EINVAL;
+        return -1;
+    }
+    cbuf[res] = '\0'; /* buf will be null terminated */
+    r1 = mbstowcs(buf, cbuf, bufsiz);
+    if (r1 == -1) {
+        errno = EINVAL;
+        return -1;
+    }
+    return (int)r1;
+}
+#endif
+
+#ifdef HAVE_REALPATH
+wchar_t*
+_Py_wrealpath(const wchar_t *path, wchar_t *resolved_path)
+{
+    char *cpath;
+    char cresolved_path[PATH_MAX];
+    char *res;
+    size_t r;
+    cpath = _Py_wchar2char(path);
+    if (cpath == NULL) {
+        errno = EINVAL;
+        return NULL;
+    }
+    res = realpath(cpath, cresolved_path);
+    PyMem_Free(cpath);
+    if (res == NULL)
+        return NULL;
+    r = mbstowcs(resolved_path, cresolved_path, PATH_MAX);
+    if (r == (size_t)-1 || r >= PATH_MAX) {
+        errno = EINVAL;
+        return NULL;
+    }
+    return resolved_path;
+}
+#endif
+
+wchar_t*
+_Py_wgetcwd(wchar_t *buf, size_t size)
+{
+#ifdef MS_WINDOWS
+    return _wgetcwd(buf, size);
+#else
+    char fname[PATH_MAX];
+    if (getcwd(fname, PATH_MAX) == NULL)
+        return NULL;
+    if (mbstowcs(buf, fname, size) >= size) {
+        errno = ERANGE;
+        return NULL;
+    }
+    return buf;
+#endif
+}
+
+#endif
+

Python/import.c

@@ -1953,73 +1953,8 @@ case_ok(char *buf, Py_ssize_t len, Py_ssize_t namelen, char *name)
 #endif
 }
 
-/* Call _wfopen() on Windows, or fopen() otherwise. Return the new file
-   object on success, or NULL if the file cannot be open or (if
-   PyErr_Occurred()) on unicode error */
-
-FILE*
-_Py_fopen(PyObject *unicode, const char *mode)
-{
-#ifdef MS_WINDOWS
-    wchar_t *path;
-    wchar_t wmode[10];
-    int usize;
-    FILE *f;
-
-    usize = MultiByteToWideChar(CP_ACP, 0, mode, -1, wmode, sizeof(wmode));
-    if (usize == 0)
-        return NULL;
-
-    path = PyUnicode_AsWideCharString(unicode, NULL);
-    if (path == NULL)
-        return NULL;
-    f = _wfopen(path, wmode);
-    PyMem_Free(path);
-    return f;
-#else
-    FILE *f;
-    PyObject *bytes = PyUnicode_EncodeFSDefault(unicode);
-    if (bytes == NULL)
-        return NULL;
-    f = fopen(PyBytes_AS_STRING(bytes), mode);
-    Py_DECREF(bytes);
-    return f;
-#endif
-}
-
 #ifdef HAVE_STAT
 
-/* Call _wstat() on Windows, or stat() otherwise. Only fill st_mode
-   attribute on Windows. Return 0 on success, -1 on stat error or (if
-   PyErr_Occurred()) unicode error. */
-
-int
-_Py_stat(PyObject *unicode, struct stat *statbuf)
-{
-#ifdef MS_WINDOWS
-    wchar_t *path;
-    int err;
-    struct _stat wstatbuf;
-
-    path = PyUnicode_AsWideCharString(unicode, NULL);
-    if (path == NULL)
-        return -1;
-    err = _wstat(path, &wstatbuf);
-    PyMem_Free(path);
-    if (!err)
-        statbuf->st_mode = wstatbuf.st_mode;
-    return err;
-#else
-    int ret;
-    PyObject *bytes = PyUnicode_EncodeFSDefault(unicode);
-    if (bytes == NULL)
-        return -1;
-    ret = stat(PyBytes_AS_STRING(bytes), statbuf);
-    Py_DECREF(bytes);
-    return ret;
-#endif
-}
-
 /* Helper to look for __init__.py or __init__.py[co] in potential package */
 static int
 find_init_module(char *buf)

Python/sysmodule.c

@@ -1657,32 +1657,6 @@ makeargvobject(int argc, wchar_t **argv)
     return av;
 }
 
-#ifdef HAVE_REALPATH
-static wchar_t*
-_wrealpath(const wchar_t *path, wchar_t *resolved_path)
-{
-    char *cpath;
-    char cresolved_path[PATH_MAX];
-    char *res;
-    size_t r;
-    cpath = _Py_wchar2char(path);
-    if (cpath == NULL) {
-        errno = EINVAL;
-        return NULL;
-    }
-    res = realpath(cpath, cresolved_path);
-    PyMem_Free(cpath);
-    if (res == NULL)
-        return NULL;
-    r = mbstowcs(resolved_path, cresolved_path, PATH_MAX);
-    if (r == (size_t)-1 || r >= PATH_MAX) {
-        errno = EINVAL;
-        return NULL;
-    }
-    return resolved_path;
-}
-#endif
-
 #define _HAVE_SCRIPT_ARGUMENT(argc, argv) \
   (argc > 0 && argv0 != NULL && \
    wcscmp(argv0, L"-c") != 0 && wcscmp(argv0, L"-m") != 0)
@@ -1696,7 +1670,6 @@ sys_update_path(int argc, wchar_t **argv)
     PyObject *a;
     PyObject *path;
 #ifdef HAVE_READLINK
-    extern int _Py_wreadlink(const wchar_t *, wchar_t *, size_t);
     wchar_t link[MAXPATHLEN+1];
     wchar_t argv0copy[2*MAXPATHLEN+1];
     int nr = 0;
@@ -1769,7 +1742,7 @@ sys_update_path(int argc, wchar_t **argv)
 #else /* All other filename syntaxes */
     if (_HAVE_SCRIPT_ARGUMENT(argc, argv)) {
 #if defined(HAVE_REALPATH)
-        if (_wrealpath(argv0, fullpath)) {
+        if (_Py_wrealpath(argv0, fullpath)) {
             argv0 = fullpath;
         }
 #endif