/* Return the initial module search path. */

#include "Python.h"

#include "pycore_fileutils.h"

#include "pycore_initconfig.h"

#include "pycore_pathconfig.h"

#include "osdefs.h" // DELIM

#include <stdlib.h> // getenv()

#include <string.h>

#include <sys/types.h>

#ifdef __APPLE__

# include <mach-o/dyld.h>

#endif

/* Search in some common locations for the associated Python libraries.

*

* Two directories must be found, the platform independent directory

* (prefix), containing the common .py and .pyc files, and the platform

* dependent directory (exec_prefix), containing the shared library

* modules. Note that prefix and exec_prefix can be the same directory,

* but for some installations, they are different.

*

* Py_GetPath() carries out separate searches for prefix and exec_prefix.

* Each search tries a number of different locations until a ``landmark''

* file or directory is found. If no prefix or exec_prefix is found, a

* warning message is issued and the preprocessor defined PREFIX and

* EXEC_PREFIX are used (even though they will not work); python carries on

* as best as is possible, but most imports will fail.

*

* Before any searches are done, the location of the executable is

* determined. If argv[0] has one or more slashes in it, it is used

* unchanged. Otherwise, it must have been invoked from the shell's path,

* so we search $PATH for the named executable and use that. If the

* executable was not found on $PATH (or there was no $PATH environment

* variable), the original argv[0] string is used.

*

* Next, the executable location is examined to see if it is a symbolic

* link. If so, the link is chased (correctly interpreting a relative

* pathname if one is found) and the directory of the link target is used.

*

* Finally, argv0_path is set to the directory containing the executable

* (i.e. the last component is stripped).

*

* With argv0_path in hand, we perform a number of steps. The same steps

* are performed for prefix and for exec_prefix, but with a different

* landmark.

*

* Step 1. Are we running python out of the build directory? This is

* checked by looking for a different kind of landmark relative to

* argv0_path. For prefix, the landmark's path is derived from the VPATH

* preprocessor variable (taking into account that its value is almost, but

* not quite, what we need). For exec_prefix, the landmark is

* pybuilddir.txt. If the landmark is found, we're done.

*

* For the remaining steps, the prefix landmark will always be

* lib/python$VERSION/os.py and the exec_prefix will always be

* lib/python$VERSION/lib-dynload, where $VERSION is Python's version

* number as supplied by the Makefile. Note that this means that no more

* build directory checking is performed; if the first step did not find

* the landmarks, the assumption is that python is running from an

* installed setup.

*

* Step 2. See if the $PYTHONHOME environment variable points to the

* installed location of the Python libraries. If $PYTHONHOME is set, then

* it points to prefix and exec_prefix. $PYTHONHOME can be a single

* directory, which is used for both, or the prefix and exec_prefix

* directories separated by a colon.

*

* Step 3. Try to find prefix and exec_prefix relative to argv0_path,

* backtracking up the path until it is exhausted. This is the most common

* step to succeed. Note that if prefix and exec_prefix are different,

* exec_prefix is more likely to be found; however if exec_prefix is a

* subdirectory of prefix, both will be found.

*

* Step 4. Search the directories pointed to by the preprocessor variables

* PREFIX and EXEC_PREFIX. These are supplied by the Makefile but can be

* passed in as options to the configure script.

*

* That's it!

*

* Well, almost. Once we have determined prefix and exec_prefix, the

* preprocessor variable PYTHONPATH is used to construct a path. Each

* relative path on PYTHONPATH is prefixed with prefix. Then the directory

* containing the shared library modules is appended. The environment

* variable $PYTHONPATH is inserted in front of it all. Finally, the

* prefix and exec_prefix globals are tweaked so they reflect the values

* expected by other code, by stripping the "lib/python$VERSION/..." stuff

* off. If either points to the build directory, the globals are reset to

* the corresponding preprocessor variables (so sys.prefix will reflect the

* installation location, even though sys.path points into the build

* directory). This seems to make more sense given that currently the only

* known use of sys.prefix and sys.exec_prefix is for the ILU installation

* process to find the installed Python tree.

*

* An embedding application can use Py_SetPath() to override all of

* these automatic path computations.

*

* NOTE: Windows MSVC builds use PC/getpathp.c instead!

*/

#ifdef __cplusplus

extern "C" {

#endif

#if (!defined(PREFIX) || !defined(EXEC_PREFIX) \

|| !defined(VERSION) || !defined(VPATH))

#error "PREFIX, EXEC_PREFIX, VERSION and VPATH macros must be defined"

#endif

#ifndef LANDMARK

#define LANDMARK L"os.py"

#endif

#define BUILD_LANDMARK L"Modules/Setup.local"

#define PATHLEN_ERR() _PyStatus_ERR("path configuration: path too long")

typedef struct {

wchar_t *path_env; /* PATH environment variable */

wchar_t *pythonpath_macro; /* PYTHONPATH macro */

wchar_t *prefix_macro; /* PREFIX macro */

wchar_t *exec_prefix_macro; /* EXEC_PREFIX macro */

wchar_t *vpath_macro; /* VPATH macro */

wchar_t *lib_python; /* <platlibdir> / "pythonX.Y" */

int prefix_found; /* found platform independent libraries? */

int exec_prefix_found; /* found the platform dependent libraries? */

int warnings;

const wchar_t *pythonpath_env;

const wchar_t *platlibdir;

wchar_t *argv0_path;

wchar_t *zip_path;

wchar_t *prefix;

wchar_t *exec_prefix;

} PyCalculatePath;

static const wchar_t delimiter[2] = {DELIM, '\0'};

static const wchar_t separator[2] = {SEP, '\0'};

static void

reduce(wchar_t *dir)

{

size_t i = wcslen(dir);

while (i > 0 && dir[i] != SEP) {

--i;

}

dir[i] = '\0';

}

/* Is file, not directory */

static int

isfile(const wchar_t *filename)

{

struct stat buf;

if (_Py_wstat(filename, &buf) != 0) {

return 0;

}

if (!S_ISREG(buf.st_mode)) {

return 0;

}

return 1;

}

/* Is executable file */

static int

isxfile(const wchar_t *filename)

{

struct stat buf;

if (_Py_wstat(filename, &buf) != 0) {

return 0;

}

if (!S_ISREG(buf.st_mode)) {

return 0;

}

if ((buf.st_mode & 0111) == 0) {

return 0;

}

return 1;

}

/* Is directory */

static int

isdir(const wchar_t *filename)

{

struct stat buf;

if (_Py_wstat(filename, &buf) != 0) {

return 0;

}

if (!S_ISDIR(buf.st_mode)) {

return 0;

}

return 1;

}

/* Add a path component, by appending stuff to buffer.

buflen: 'buffer' length in characters including trailing NUL.

If path2 is empty:

- if path doesn't end with SEP and is not empty, add SEP to path

- otherwise, do nothing. */

static PyStatus

joinpath(wchar_t *path, const wchar_t *path2, size_t path_len)

{

if (_Py_isabs(path2)) {

if (wcslen(path2) >= path_len) {

return PATHLEN_ERR();

}

wcscpy(path, path2);

}

else {

if (_Py_add_relfile(path, path2, path_len) < 0) {

return PATHLEN_ERR();

}

return _PyStatus_OK();

}

return _PyStatus_OK();

}

static wchar_t*

substring(const wchar_t *str, size_t len)

{

wchar_t *substr = PyMem_RawMalloc((len + 1) * sizeof(wchar_t));

if (substr == NULL) {

return NULL;

}

if (len) {

memcpy(substr, str, len * sizeof(wchar_t));

}

substr[len] = L'\0';

return substr;

}

static wchar_t*

joinpath2(const wchar_t *path, const wchar_t *path2)

{

if (_Py_isabs(path2)) {

return _PyMem_RawWcsdup(path2);

}

return _Py_join_relfile(path, path2);

}

static inline int

safe_wcscpy(wchar_t *dst, const wchar_t *src, size_t n)

{

size_t srclen = wcslen(src);

if (n <= srclen) {

dst[0] = L'\0';

return -1;

}

memcpy(dst, src, (srclen + 1) * sizeof(wchar_t));

return 0;

}

/* copy_absolute requires that path be allocated at least

'abs_path_len' characters (including trailing NUL). */

static PyStatus

copy_absolute(wchar_t *abs_path, const wchar_t *path, size_t abs_path_len)

{

if (_Py_isabs(path)) {

if (safe_wcscpy(abs_path, path, abs_path_len) < 0) {

return PATHLEN_ERR();

}

}

else {

if (!_Py_wgetcwd(abs_path, abs_path_len)) {

/* unable to get the current directory */

if (safe_wcscpy(abs_path, path, abs_path_len) < 0) {

return PATHLEN_ERR();

}

return _PyStatus_OK();

}

if (path[0] == '.' && path[1] == SEP) {

path += 2;

}

PyStatus status = joinpath(abs_path, path, abs_path_len);

if (_PyStatus_EXCEPTION(status)) {

return status;

}

}

return _PyStatus_OK();

}

/* path_len: path length in characters including trailing NUL */

static PyStatus

absolutize(wchar_t **path_p)

{

assert(!_Py_isabs(*path_p));

wchar_t abs_path[MAXPATHLEN+1];

wchar_t *path = *path_p;

PyStatus status = copy_absolute(abs_path, path, Py_ARRAY_LENGTH(abs_path));

if (_PyStatus_EXCEPTION(status)) {

return status;

}

PyMem_RawFree(*path_p);

*path_p = _PyMem_RawWcsdup(abs_path);

if (*path_p == NULL) {

return _PyStatus_NO_MEMORY();

}

return _PyStatus_OK();

}

/* Is module -- check for .pyc too */

static PyStatus

ismodule(const wchar_t *path, int *result)

{

wchar_t *filename = joinpath2(path, LANDMARK);

if (filename == NULL) {

return _PyStatus_NO_MEMORY();

}

if (isfile(filename)) {

PyMem_RawFree(filename);

*result = 1;

return _PyStatus_OK();

}

/* Check for the compiled version of prefix. */

size_t len = wcslen(filename);

wchar_t *pyc = PyMem_RawMalloc((len + 2) * sizeof(wchar_t));

if (pyc == NULL) {

PyMem_RawFree(filename);

return _PyStatus_NO_MEMORY();

}

memcpy(pyc, filename, len * sizeof(wchar_t));

pyc[len] = L'c';

pyc[len + 1] = L'\0';

*result = isfile(pyc);

PyMem_RawFree(filename);

PyMem_RawFree(pyc);

return _PyStatus_OK();

}

#if defined(__CYGWIN__) || defined(__MINGW32__)

#ifndef EXE_SUFFIX

#define EXE_SUFFIX L".exe"

#endif

/* pathlen: 'path' length in characters including trailing NUL */

static PyStatus

add_exe_suffix(wchar_t **progpath_p)

{

wchar_t *progpath = *progpath_p;

/* Check for already have an executable suffix */

size_t n = wcslen(progpath);

size_t s = wcslen(EXE_SUFFIX);

if (wcsncasecmp(EXE_SUFFIX, progpath + n - s, s) == 0) {

return _PyStatus_OK();

}

wchar_t *progpath2 = PyMem_RawMalloc((n + s + 1) * sizeof(wchar_t));

if (progpath2 == NULL) {

return _PyStatus_NO_MEMORY();

}

memcpy(progpath2, progpath, n * sizeof(wchar_t));

memcpy(progpath2 + n, EXE_SUFFIX, s * sizeof(wchar_t));

progpath2[n+s] = L'\0';

if (isxfile(progpath2)) {

PyMem_RawFree(*progpath_p);

*progpath_p = progpath2;

}

else {

PyMem_RawFree(progpath2);

}

return _PyStatus_OK();

}

#endif

/* search_for_prefix requires that argv0_path be no more than MAXPATHLEN

bytes long.

*/

static PyStatus

search_for_prefix(PyCalculatePath *calculate, _PyPathConfig *pathconfig,

wchar_t *prefix, size_t prefix_len, int *found)

{

PyStatus status;

/* If PYTHONHOME is set, we believe it unconditionally */

if (pathconfig->home) {

/* Path: <home> / <lib_python> */

if (safe_wcscpy(prefix, pathconfig->home, prefix_len) < 0) {

return PATHLEN_ERR();

}

wchar_t *delim = wcschr(prefix, DELIM);

if (delim) {

*delim = L'\0';

}

status = joinpath(prefix, calculate->lib_python, prefix_len);

if (_PyStatus_EXCEPTION(status)) {

return status;

}

*found = 1;

return _PyStatus_OK();

}

/* Check to see if argv0_path is in the build directory

Path: <argv0_path> / <BUILD_LANDMARK define> */

wchar_t *path = joinpath2(calculate->argv0_path, BUILD_LANDMARK);

if (path == NULL) {

return _PyStatus_NO_MEMORY();

}

int is_build_dir = isfile(path);

PyMem_RawFree(path);

if (is_build_dir) {

/* argv0_path is the build directory (BUILD_LANDMARK exists),

now also check LANDMARK using ismodule(). */

/* Path: <argv0_path> / <VPATH macro> / Lib */

/* or if VPATH is empty: <argv0_path> / Lib */

if (safe_wcscpy(prefix, calculate->argv0_path, prefix_len) < 0) {

return PATHLEN_ERR();

}

status = joinpath(prefix, calculate->vpath_macro, prefix_len);

if (_PyStatus_EXCEPTION(status)) {

return status;

}

status = joinpath(prefix, L"Lib", prefix_len);

if (_PyStatus_EXCEPTION(status)) {

return status;

}

int module;

status = ismodule(prefix, &module);

if (_PyStatus_EXCEPTION(status)) {

return status;

}

if (module) {

/* BUILD_LANDMARK and LANDMARK found */

*found = -1;

return _PyStatus_OK();

}

}

/* Search from argv0_path, until root is found */

status = copy_absolute(prefix, calculate->argv0_path, prefix_len);

if (_PyStatus_EXCEPTION(status)) {

return status;

}

do {

/* Path: <argv0_path or substring> / <lib_python> / LANDMARK */

size_t n = wcslen(prefix);

status = joinpath(prefix, calculate->lib_python, prefix_len);

if (_PyStatus_EXCEPTION(status)) {

return status;

}

int module;

status = ismodule(prefix, &module);

if (_PyStatus_EXCEPTION(status)) {

return status;

}

if (module) {

*found = 1;

return _PyStatus_OK();

}

prefix[n] = L'\0';

reduce(prefix);

} while (prefix[0]);

/* Look at configure's PREFIX.

Path: <PREFIX macro> / <lib_python> / LANDMARK */

if (safe_wcscpy(prefix, calculate->prefix_macro, prefix_len) < 0) {

return PATHLEN_ERR();

}

status = joinpath(prefix, calculate->lib_python, prefix_len);

if (_PyStatus_EXCEPTION(status)) {

return status;

}

int module;

status = ismodule(prefix, &module);

if (_PyStatus_EXCEPTION(status)) {

return status;

}

if (module) {

*found = 1;

return _PyStatus_OK();

}

/* Fail */

*found = 0;

return _PyStatus_OK();

}

static PyStatus

calculate_set_stdlib_dir(PyCalculatePath *calculate, _PyPathConfig *pathconfig)

{

// Note that, unlike calculate_set_prefix(), here we allow a negative

// prefix_found. That means the source tree Lib dir gets used.

if (!calculate->prefix_found) {

return _PyStatus_OK();

}

PyStatus status;

wchar_t *prefix = calculate->prefix;

if (!_Py_isabs(prefix)) {

prefix = _PyMem_RawWcsdup(prefix);

if (prefix == NULL) {

return _PyStatus_NO_MEMORY();

}

status = absolutize(&prefix);

if (_PyStatus_EXCEPTION(status)) {

return status;

}

}

wchar_t buf[MAXPATHLEN + 1];

int res = _Py_normalize_path(prefix, buf, Py_ARRAY_LENGTH(buf));

if (prefix != calculate->prefix) {

PyMem_RawFree(prefix);

}

if (res < 0) {

return PATHLEN_ERR();

}

pathconfig->stdlib_dir = _PyMem_RawWcsdup(buf);

if (pathconfig->stdlib_dir == NULL) {

return _PyStatus_NO_MEMORY();

}

return _PyStatus_OK();

}

static PyStatus

calculate_prefix(PyCalculatePath *calculate, _PyPathConfig *pathconfig)

{

wchar_t prefix[MAXPATHLEN+1];

memset(prefix, 0, sizeof(prefix));

size_t prefix_len = Py_ARRAY_LENGTH(prefix);

PyStatus status;

status = search_for_prefix(calculate, pathconfig,

prefix, prefix_len,

&calculate->prefix_found);

if (_PyStatus_EXCEPTION(status)) {

return status;

}

if (!calculate->prefix_found) {

if (calculate->warnings) {

fprintf(stderr,

"Could not find platform independent libraries <prefix>\n");

}

calculate->prefix = joinpath2(calculate->prefix_macro,

calculate->lib_python);

}

else {

calculate->prefix = _PyMem_RawWcsdup(prefix);

}

if (calculate->prefix == NULL) {

return _PyStatus_NO_MEMORY();

}

return _PyStatus_OK();

}

static PyStatus

calculate_set_prefix(PyCalculatePath *calculate, _PyPathConfig *pathconfig)

{

/* Reduce prefix and exec_prefix to their essence,

* e.g. /usr/local/lib/python1.5 is reduced to /usr/local.

* If we're loading relative to the build directory,

* return the compiled-in defaults instead.

*/

if (calculate->prefix_found > 0) {

wchar_t *prefix = _PyMem_RawWcsdup(calculate->prefix);

if (prefix == NULL) {

return _PyStatus_NO_MEMORY();

}

reduce(prefix);

reduce(prefix);

if (prefix[0]) {

pathconfig->prefix = prefix;

}

else {

PyMem_RawFree(prefix);

/* The prefix is the root directory, but reduce() chopped

off the "/". */

pathconfig->prefix = _PyMem_RawWcsdup(separator);

if (pathconfig->prefix == NULL) {

return _PyStatus_NO_MEMORY();

}

}

}

else {

pathconfig->prefix = _PyMem_RawWcsdup(calculate->prefix_macro);

if (pathconfig->prefix == NULL) {

return _PyStatus_NO_MEMORY();

}

}

return _PyStatus_OK();

}

static PyStatus

calculate_pybuilddir(const wchar_t *argv0_path,

wchar_t *exec_prefix, size_t exec_prefix_len,

int *found)

{

PyStatus status;

/* Check to see if argv[0] is in the build directory. "pybuilddir.txt"

is written by setup.py and contains the relative path to the location

of shared library modules.

Filename: <argv0_path> / "pybuilddir.txt" */

wchar_t *filename = joinpath2(argv0_path, L"pybuilddir.txt");

if (filename == NULL) {

return _PyStatus_NO_MEMORY();

}

FILE *fp = _Py_wfopen(filename, L"rb");

PyMem_RawFree(filename);

if (fp == NULL) {

errno = 0;

return _PyStatus_OK();

}

char buf[MAXPATHLEN + 1];

size_t n = fread(buf, 1, Py_ARRAY_LENGTH(buf) - 1, fp);

buf[n] = '\0';

fclose(fp);

size_t dec_len;

wchar_t *pybuilddir = _Py_DecodeUTF8_surrogateescape(buf, n, &dec_len);

if (!pybuilddir) {

return DECODE_LOCALE_ERR("pybuilddir.txt", dec_len);

}

/* Path: <argv0_path> / <pybuilddir content> */

if (safe_wcscpy(exec_prefix, argv0_path, exec_prefix_len) < 0) {

PyMem_RawFree(pybuilddir);

return PATHLEN_ERR();

}

status = joinpath(exec_prefix, pybuilddir, exec_prefix_len);

PyMem_RawFree(pybuilddir);

if (_PyStatus_EXCEPTION(status)) {

return status;

}

*found = -1;

return _PyStatus_OK();

}

/* search_for_exec_prefix requires that argv0_path be no more than

MAXPATHLEN bytes long.

*/

static PyStatus

search_for_exec_prefix(PyCalculatePath *calculate, _PyPathConfig *pathconfig,

wchar_t *exec_prefix, size_t exec_prefix_len,

int *found)

{

PyStatus status;

/* If PYTHONHOME is set, we believe it unconditionally */

if (pathconfig->home) {

/* Path: <home> / <lib_python> / "lib-dynload" */

wchar_t *delim = wcschr(pathconfig->home, DELIM);

if (delim) {

if (safe_wcscpy(exec_prefix, delim+1, exec_prefix_len) < 0) {

return PATHLEN_ERR();

}

}

else {

if (safe_wcscpy(exec_prefix, pathconfig->home, exec_prefix_len) < 0) {

return PATHLEN_ERR();

}

}

status = joinpath(exec_prefix, calculate->lib_python, exec_prefix_len);

if (_PyStatus_EXCEPTION(status)) {

return status;

}

status = joinpath(exec_prefix, L"lib-dynload", exec_prefix_len);

if (_PyStatus_EXCEPTION(status)) {

return status;

}

*found = 1;

return _PyStatus_OK();

}

/* Check for pybuilddir.txt */

assert(*found == 0);

status = calculate_pybuilddir(calculate->argv0_path,

exec_prefix, exec_prefix_len, found);

if (_PyStatus_EXCEPTION(status)) {

return status;

}

if (*found) {

return _PyStatus_OK();

}

/* Search from argv0_path, until root is found */

status = copy_absolute(exec_prefix, calculate->argv0_path, exec_prefix_len);

if (_PyStatus_EXCEPTION(status)) {

return status;

}

do {

/* Path: <argv0_path or substring> / <lib_python> / "lib-dynload" */

size_t n = wcslen(exec_prefix);

status = joinpath(exec_prefix, calculate->lib_python, exec_prefix_len);

if (_PyStatus_EXCEPTION(status)) {

return status;

}

status = joinpath(exec_prefix, L"lib-dynload", exec_prefix_len);

if (_PyStatus_EXCEPTION(status)) {

return status;

}

if (isdir(exec_prefix)) {

*found = 1;

return _PyStatus_OK();

}

exec_prefix[n] = L'\0';

reduce(exec_prefix);

} while (exec_prefix[0]);

/* Look at configure's EXEC_PREFIX.

Path: <EXEC_PREFIX macro> / <lib_python> / "lib-dynload" */

if (safe_wcscpy(exec_prefix, calculate->exec_prefix_macro, exec_prefix_len) < 0) {

return PATHLEN_ERR();

}

status = joinpath(exec_prefix, calculate->lib_python, exec_prefix_len);

if (_PyStatus_EXCEPTION(status)) {

return status;

}

status = joinpath(exec_prefix, L"lib-dynload", exec_prefix_len);

if (_PyStatus_EXCEPTION(status)) {

return status;

}

if (isdir(exec_prefix)) {

*found = 1;

return _PyStatus_OK();

}

/* Fail */

*found = 0;

return _PyStatus_OK();

}

static PyStatus

calculate_exec_prefix(PyCalculatePath *calculate, _PyPathConfig *pathconfig)

{

PyStatus status;

wchar_t exec_prefix[MAXPATHLEN+1];

memset(exec_prefix, 0, sizeof(exec_prefix));

size_t exec_prefix_len = Py_ARRAY_LENGTH(exec_prefix);

status = search_for_exec_prefix(calculate, pathconfig,

exec_prefix, exec_prefix_len,

&calculate->exec_prefix_found);

if (_PyStatus_EXCEPTION(status)) {

return status;

}

if (!calculate->exec_prefix_found) {

if (calculate->warnings) {

fprintf(stderr,

"Could not find platform dependent libraries <exec_prefix>\n");

}

/* <platlibdir> / "lib-dynload" */

wchar_t *lib_dynload = joinpath2(calculate->platlibdir,

L"lib-dynload");

if (lib_dynload == NULL) {

return _PyStatus_NO_MEMORY();

}

calculate->exec_prefix = joinpath2(calculate->exec_prefix_macro,

lib_dynload);

PyMem_RawFree(lib_dynload);

if (calculate->exec_prefix == NULL) {

return _PyStatus_NO_MEMORY();

}

}

else {

/* If we found EXEC_PREFIX do *not* reduce it! (Yet.) */

calculate->exec_prefix = _PyMem_RawWcsdup(exec_prefix);

if (calculate->exec_prefix == NULL) {

return _PyStatus_NO_MEMORY();

}

}

return _PyStatus_OK();

}

static PyStatus

calculate_set_exec_prefix(PyCalculatePath *calculate,

_PyPathConfig *pathconfig)

{

if (calculate->exec_prefix_found > 0) {

wchar_t *exec_prefix = _PyMem_RawWcsdup(calculate->exec_prefix);

if (exec_prefix == NULL) {

return _PyStatus_NO_MEMORY();

}

reduce(exec_prefix);

reduce(exec_prefix);

reduce(exec_prefix);

if (exec_prefix[0]) {

pathconfig->exec_prefix = exec_prefix;

}

else {

/* empty string: use SEP instead */

PyMem_RawFree(exec_prefix);

/* The exec_prefix is the root directory, but reduce() chopped

off the "/". */

pathconfig->exec_prefix = _PyMem_RawWcsdup(separator);

if (pathconfig->exec_prefix == NULL) {

return _PyStatus_NO_MEMORY();

}

}

}

else {

pathconfig->exec_prefix = _PyMem_RawWcsdup(calculate->exec_prefix_macro);

if (pathconfig->exec_prefix == NULL) {

return _PyStatus_NO_MEMORY();

}

}

return _PyStatus_OK();

}

/* Similar to shutil.which().

If found, write the path into *abs_path_p. */

static PyStatus

calculate_which(const wchar_t *path_env, wchar_t *program_name,

wchar_t **abs_path_p)

{

while (1) {

wchar_t *delim = wcschr(path_env, DELIM);

wchar_t *abs_path;

if (delim) {

wchar_t *path = substring(path_env, delim - path_env);

if (path == NULL) {

return _PyStatus_NO_MEMORY();

}

abs_path = joinpath2(path, program_name);

PyMem_RawFree(path);

}

else {

abs_path = joinpath2(path_env, program_name);

}

if (abs_path == NULL) {

return _PyStatus_NO_MEMORY();

}

if (isxfile(abs_path)) {

*abs_path_p = abs_path;

return _PyStatus_OK();

}

PyMem_RawFree(abs_path);

if (!delim) {

break;

}

path_env = delim + 1;

}

/* not found */

return _PyStatus_OK();

}

#ifdef __APPLE__

static PyStatus

calculate_program_macos(wchar_t **abs_path_p)

{

char execpath[MAXPATHLEN + 1];

uint32_t nsexeclength = Py_ARRAY_LENGTH(execpath) - 1;

/* On Mac OS X, if a script uses an interpreter of the form

"#!/opt/python2.3/bin/python", the kernel only passes "python"

as argv[0], which falls through to the $PATH search below.

If /opt/python2.3/bin isn't in your path, or is near the end,

this algorithm may incorrectly find /usr/bin/python. To work

around this, we can use _NSGetExecutablePath to get a better

hint of what the intended interpreter was, although this

will fail if a relative path was used. but in that case,

absolutize() should help us out below

*/

if (_NSGetExecutablePath(execpath, &nsexeclength) != 0

|| (wchar_t)execpath[0] != SEP)

{

/* _NSGetExecutablePath() failed or the path is relative */

return _PyStatus_OK();

}

size_t len;

*abs_path_p = Py_DecodeLocale(execpath, &len);

if (*abs_path_p == NULL) {

return DECODE_LOCALE_ERR("executable path", len);

}

return _PyStatus_OK();

}

#endif /* __APPLE__ */

static PyStatus

calculate_program_impl(PyCalculatePath *calculate, _PyPathConfig *pathconfig)

{

assert(pathconfig->program_full_path == NULL);

PyStatus status;

/* If there is no slash in the argv0 path, then we have to

* assume python is on the user's $PATH, since there's no

* other way to find a directory to start the search from. If

* $PATH isn't exported, you lose.

*/

if (wcschr(pathconfig->program_name, SEP)) {

pathconfig->program_full_path = _PyMem_RawWcsdup(pathconfig->program_name);

if (pathconfig->program_full_path == NULL) {

return _PyStatus_NO_MEMORY();

}

return _PyStatus_OK();

}

#ifdef __APPLE__

wchar_t *abs_path = NULL;

status = calculate_program_macos(&abs_path);

if (_PyStatus_EXCEPTION(status)) {

return status;

}

if (abs_path) {

pathconfig->program_full_path = abs_path;

return _PyStatus_OK();

}

#endif /* __APPLE__ */

if (calculate->path_env) {

wchar_t *abs_path = NULL;

status = calculate_which(calculate->path_env, pathconfig->program_name,

&abs_path);

if (_PyStatus_EXCEPTION(status)) {

return status;

}

if (abs_path) {

pathconfig->program_full_path = abs_path;

return _PyStatus_OK();

}

}

/* In the last resort, use an empty string */

pathconfig->program_full_path = _PyMem_RawWcsdup(L"");

if (pathconfig->program_full_path == NULL) {

return _PyStatus_NO_MEMORY();

}

return _PyStatus_OK();

}

/* Calculate pathconfig->program_full_path */

static PyStatus

calculate_program(PyCalculatePath *calculate, _PyPathConfig *pathconfig)