/* Return the initial module search path. */

#include "Python.h"

#include "internal/pystate.h"

#include "osdefs.h"

#include <sys/types.h>

#include <string.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 authomatic 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 must be constant defined"

#endif

#ifndef LANDMARK

#define LANDMARK L"os.py"

#endif

#define DECODE_LOCALE_ERR(NAME, LEN) \

((LEN) == (size_t)-2) \

? _Py_INIT_USER_ERR("cannot decode " NAME) \

: _Py_INIT_NO_MEMORY()

typedef struct {

wchar_t *path_env; /* PATH environment variable */

wchar_t *pythonpath; /* PYTHONPATH define */

wchar_t *prefix; /* PREFIX define */

wchar_t *exec_prefix; /* EXEC_PREFIX define */

wchar_t *lib_python; /* "lib/pythonX.Y" */

wchar_t argv0_path[MAXPATHLEN+1];

wchar_t zip_path[MAXPATHLEN+1]; /* ".../lib/pythonXY.zip" */

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

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

} PyCalculatePath;

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

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

/* Get file status. Encode the path to the locale encoding. */

static int

_Py_wstat(const wchar_t* path, struct stat *buf)

{

int err;

char *fname;

fname = _Py_EncodeLocaleRaw(path, NULL);

if (fname == NULL) {

errno = EINVAL;

return -1;

}

err = stat(fname, buf);

PyMem_RawFree(fname);

return err;

}

static void

reduce(wchar_t *dir)

{

size_t i = wcslen(dir);

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

--i;

dir[i] = '\0';

}

static int

isfile(wchar_t *filename) /* Is file, not directory */

{

struct stat buf;

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

return 0;

}

if (!S_ISREG(buf.st_mode)) {

return 0;

}

return 1;

}

static int

ismodule(wchar_t *filename) /* Is module -- check for .pyc too */

{

if (isfile(filename)) {

return 1;

}

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

if (wcslen(filename) < MAXPATHLEN) {

wcscat(filename, L"c");

if (isfile(filename)) {

return 1;

}

}

return 0;

}

/* Is executable file */

static int

isxfile(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(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.

buffer must have at least MAXPATHLEN + 1 bytes allocated, and contain a

NUL-terminated string with no more than MAXPATHLEN characters (not counting

the trailing NUL). It's a fatal error if it contains a string longer than

that (callers must be careful!). If these requirements are met, it's

guaranteed that buffer will still be a NUL-terminated string with no more

than MAXPATHLEN characters at exit. If stuff is too long, only as much of

stuff as fits will be appended.

*/

static void

joinpath(wchar_t *buffer, wchar_t *stuff)

{

size_t n, k;

if (stuff[0] == SEP) {

n = 0;

}

else {

n = wcslen(buffer);

if (n > 0 && buffer[n-1] != SEP && n < MAXPATHLEN) {

buffer[n++] = SEP;

}

}

if (n > MAXPATHLEN) {

Py_FatalError("buffer overflow in getpath.c's joinpath()");

}

k = wcslen(stuff);

if (n + k > MAXPATHLEN) {

k = MAXPATHLEN - n;

}

wcsncpy(buffer+n, stuff, k);

buffer[n+k] = '\0';

}

/* copy_absolute requires that path be allocated at least

MAXPATHLEN + 1 bytes and that p be no more than MAXPATHLEN bytes. */

static void

copy_absolute(wchar_t *path, wchar_t *p, size_t pathlen)

{

if (p[0] == SEP) {

wcscpy(path, p);

}

else {

if (!_Py_wgetcwd(path, pathlen)) {

/* unable to get the current directory */

wcscpy(path, p);

return;

}

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

p += 2;

}

joinpath(path, p);

}

}

/* absolutize() requires that path be allocated at least MAXPATHLEN+1 bytes. */

static void

absolutize(wchar_t *path)

{

wchar_t buffer[MAXPATHLEN+1];

if (path[0] == SEP) {

return;

}

copy_absolute(buffer, path, MAXPATHLEN+1);

wcscpy(path, buffer);

}

/* search_for_prefix requires that argv0_path be no more than MAXPATHLEN

bytes long.

*/

static int

search_for_prefix(const _PyCoreConfig *core_config,

PyCalculatePath *calculate, wchar_t *prefix)

{

size_t n;

wchar_t *vpath;

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

if (core_config->home) {

wcsncpy(prefix, core_config->home, MAXPATHLEN);

prefix[MAXPATHLEN] = L'\0';

wchar_t *delim = wcschr(prefix, DELIM);

if (delim) {

*delim = L'\0';

}

joinpath(prefix, calculate->lib_python);

joinpath(prefix, LANDMARK);

return 1;

}

/* Check to see if argv[0] is in the build directory */

wcsncpy(prefix, calculate->argv0_path, MAXPATHLEN);

prefix[MAXPATHLEN] = L'\0';

joinpath(prefix, L"Modules/Setup");

if (isfile(prefix)) {

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

vpath = Py_DecodeLocale(VPATH, NULL);

if (vpath != NULL) {

wcsncpy(prefix, calculate->argv0_path, MAXPATHLEN);

prefix[MAXPATHLEN] = L'\0';

joinpath(prefix, vpath);

PyMem_RawFree(vpath);

joinpath(prefix, L"Lib");

joinpath(prefix, LANDMARK);

if (ismodule(prefix)) {

return -1;

}

}

}

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

copy_absolute(prefix, calculate->argv0_path, MAXPATHLEN+1);

do {

n = wcslen(prefix);

joinpath(prefix, calculate->lib_python);

joinpath(prefix, LANDMARK);

if (ismodule(prefix)) {

return 1;

}

prefix[n] = L'\0';

reduce(prefix);

} while (prefix[0]);

/* Look at configure's PREFIX */

wcsncpy(prefix, calculate->prefix, MAXPATHLEN);

prefix[MAXPATHLEN] = L'\0';

joinpath(prefix, calculate->lib_python);

joinpath(prefix, LANDMARK);

if (ismodule(prefix)) {

return 1;

}

/* Fail */

return 0;

}

static void

calculate_prefix(const _PyCoreConfig *core_config,

PyCalculatePath *calculate, wchar_t *prefix)

{

calculate->prefix_found = search_for_prefix(core_config, calculate, prefix);

if (!calculate->prefix_found) {

if (!Py_FrozenFlag) {

fprintf(stderr,

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

}

wcsncpy(prefix, calculate->prefix, MAXPATHLEN);

joinpath(prefix, calculate->lib_python);

}

else {

reduce(prefix);

}

}

static void

calculate_reduce_prefix(PyCalculatePath *calculate, wchar_t *prefix)

{

/* 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) {

reduce(prefix);

reduce(prefix);

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

* off the "/". */

if (!prefix[0]) {

wcscpy(prefix, separator);

}

}

else {

wcsncpy(prefix, calculate->prefix, MAXPATHLEN);

}

}

/* search_for_exec_prefix requires that argv0_path be no more than

MAXPATHLEN bytes long.

*/

static int

search_for_exec_prefix(const _PyCoreConfig *core_config,

PyCalculatePath *calculate, wchar_t *exec_prefix)

{

size_t n;

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

if (core_config->home) {

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

if (delim) {

wcsncpy(exec_prefix, delim+1, MAXPATHLEN);

}

else {

wcsncpy(exec_prefix, core_config->home, MAXPATHLEN);

}

exec_prefix[MAXPATHLEN] = L'\0';

joinpath(exec_prefix, calculate->lib_python);

joinpath(exec_prefix, L"lib-dynload");

return 1;

}

/* 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. */

wcsncpy(exec_prefix, calculate->argv0_path, MAXPATHLEN);

exec_prefix[MAXPATHLEN] = L'\0';

joinpath(exec_prefix, L"pybuilddir.txt");

if (isfile(exec_prefix)) {

FILE *f = _Py_wfopen(exec_prefix, L"rb");

if (f == NULL) {

errno = 0;

}

else {

char buf[MAXPATHLEN+1];

wchar_t *rel_builddir_path;

n = fread(buf, 1, MAXPATHLEN, f);

buf[n] = '\0';

fclose(f);

rel_builddir_path = _Py_DecodeUTF8_surrogateescape(buf, n);

if (rel_builddir_path) {

wcsncpy(exec_prefix, calculate->argv0_path, MAXPATHLEN);

exec_prefix[MAXPATHLEN] = L'\0';

joinpath(exec_prefix, rel_builddir_path);

PyMem_RawFree(rel_builddir_path );

return -1;

}

}

}

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

copy_absolute(exec_prefix, calculate->argv0_path, MAXPATHLEN+1);

do {

n = wcslen(exec_prefix);

joinpath(exec_prefix, calculate->lib_python);

joinpath(exec_prefix, L"lib-dynload");

if (isdir(exec_prefix)) {

return 1;

}

exec_prefix[n] = L'\0';

reduce(exec_prefix);

} while (exec_prefix[0]);

/* Look at configure's EXEC_PREFIX */

wcsncpy(exec_prefix, calculate->exec_prefix, MAXPATHLEN);

exec_prefix[MAXPATHLEN] = L'\0';

joinpath(exec_prefix, calculate->lib_python);

joinpath(exec_prefix, L"lib-dynload");

if (isdir(exec_prefix)) {

return 1;

}

/* Fail */

return 0;

}

static void

calculate_exec_prefix(const _PyCoreConfig *core_config,

PyCalculatePath *calculate, wchar_t *exec_prefix)

{

calculate->exec_prefix_found = search_for_exec_prefix(core_config,

calculate,

exec_prefix);

if (!calculate->exec_prefix_found) {

if (!Py_FrozenFlag) {

fprintf(stderr,

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

}

wcsncpy(exec_prefix, calculate->exec_prefix, MAXPATHLEN);

joinpath(exec_prefix, L"lib/lib-dynload");

}

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

}

static void

calculate_reduce_exec_prefix(PyCalculatePath *calculate, wchar_t *exec_prefix)

{

if (calculate->exec_prefix_found > 0) {

reduce(exec_prefix);

reduce(exec_prefix);

reduce(exec_prefix);

if (!exec_prefix[0]) {

wcscpy(exec_prefix, separator);

}

}

else {

wcsncpy(exec_prefix, calculate->exec_prefix, MAXPATHLEN);

}

}

static _PyInitError

calculate_program_full_path(const _PyCoreConfig *core_config,

PyCalculatePath *calculate, _PyPathConfig *config)

{

wchar_t program_full_path[MAXPATHLEN+1];

memset(program_full_path, 0, sizeof(program_full_path));

#ifdef __APPLE__

#if MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_4

uint32_t nsexeclength = MAXPATHLEN;

#else

unsigned long nsexeclength = MAXPATHLEN;

#endif

char execpath[MAXPATHLEN+1];

#endif

/* 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(core_config->program_name, SEP)) {

wcsncpy(program_full_path, core_config->program_name, MAXPATHLEN);

}

#ifdef __APPLE__

/* 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

*/

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

execpath[0] == SEP)

{

size_t len;

wchar_t *path = Py_DecodeLocale(execpath, &len);

if (path == NULL) {

return DECODE_LOCALE_ERR("executable path", len);

}

wcsncpy(program_full_path, path, MAXPATHLEN);

PyMem_RawFree(path);

}

#endif /* __APPLE__ */

else if (calculate->path_env) {

wchar_t *path = calculate->path_env;

while (1) {

wchar_t *delim = wcschr(path, DELIM);

if (delim) {

size_t len = delim - path;

if (len > MAXPATHLEN) {

len = MAXPATHLEN;

}

wcsncpy(program_full_path, path, len);

program_full_path[len] = '\0';

}

else {

wcsncpy(program_full_path, path, MAXPATHLEN);

}

joinpath(program_full_path, core_config->program_name);

if (isxfile(program_full_path)) {

break;

}

if (!delim) {

program_full_path[0] = L'\0';

break;

}

path = delim + 1;

}

}

else {

program_full_path[0] = '\0';

}

if (program_full_path[0] != SEP && program_full_path[0] != '\0') {

absolutize(program_full_path);

}

config->program_full_path = _PyMem_RawWcsdup(program_full_path);

if (config->program_full_path == NULL) {

return _Py_INIT_NO_MEMORY();

}

return _Py_INIT_OK();

}

static _PyInitError

calculate_argv0_path(PyCalculatePath *calculate, const wchar_t *program_full_path)

{

wcsncpy(calculate->argv0_path, program_full_path, MAXPATHLEN);

calculate->argv0_path[MAXPATHLEN] = '\0';

#ifdef WITH_NEXT_FRAMEWORK

NSModule pythonModule;

/* On Mac OS X we have a special case if we're running from a framework.

** This is because the python home should be set relative to the library,

** which is in the framework, not relative to the executable, which may

** be outside of the framework. Except when we're in the build directory...

*/

pythonModule = NSModuleForSymbol(NSLookupAndBindSymbol("_Py_Initialize"));

/* Use dylib functions to find out where the framework was loaded from */

const char* modPath = NSLibraryNameForModule(pythonModule);

if (modPath != NULL) {

/* We're in a framework. */

/* See if we might be in the build directory. The framework in the

** build directory is incomplete, it only has the .dylib and a few

** needed symlinks, it doesn't have the Lib directories and such.

** If we're running with the framework from the build directory we must

** be running the interpreter in the build directory, so we use the

** build-directory-specific logic to find Lib and such.

*/

size_t len;

wchar_t* wbuf = Py_DecodeLocale(modPath, &len);

if (wbuf == NULL) {

return DECODE_LOCALE_ERR("framework location", len);

}

wcsncpy(calculate->argv0_path, wbuf, MAXPATHLEN);

reduce(calculate->argv0_path);

joinpath(calculate->argv0_path, calculate->lib_python);

joinpath(calculate->argv0_path, LANDMARK);

if (!ismodule(calculate->argv0_path)) {

/* We are in the build directory so use the name of the

executable - we know that the absolute path is passed */

wcsncpy(calculate->argv0_path, program_full_path, MAXPATHLEN);

}

else {

/* Use the location of the library as the program_full_path */

wcsncpy(calculate->argv0_path, wbuf, MAXPATHLEN);

}

PyMem_RawFree(wbuf);

}

#endif

#if HAVE_READLINK

wchar_t tmpbuffer[MAXPATHLEN+1];

int linklen = _Py_wreadlink(program_full_path, tmpbuffer, MAXPATHLEN);

while (linklen != -1) {

if (tmpbuffer[0] == SEP) {

/* tmpbuffer should never be longer than MAXPATHLEN,

but extra check does not hurt */

wcsncpy(calculate->argv0_path, tmpbuffer, MAXPATHLEN);

}

else {

/* Interpret relative to program_full_path */

reduce(calculate->argv0_path);

joinpath(calculate->argv0_path, tmpbuffer);

}

linklen = _Py_wreadlink(calculate->argv0_path, tmpbuffer, MAXPATHLEN);

}

#endif /* HAVE_READLINK */

reduce(calculate->argv0_path);

/* At this point, argv0_path is guaranteed to be less than

MAXPATHLEN bytes long. */

return _Py_INIT_OK();

}

/* Search for an "pyvenv.cfg" environment configuration file, first in the

executable's directory and then in the parent directory.

If found, open it for use when searching for prefixes.

*/

static void

calculate_read_pyenv(PyCalculatePath *calculate)

{

wchar_t tmpbuffer[MAXPATHLEN+1];

wchar_t *env_cfg = L"pyvenv.cfg";

FILE *env_file;

wcscpy(tmpbuffer, calculate->argv0_path);

joinpath(tmpbuffer, env_cfg);

env_file = _Py_wfopen(tmpbuffer, L"r");

if (env_file == NULL) {

errno = 0;

reduce(tmpbuffer);

reduce(tmpbuffer);

joinpath(tmpbuffer, env_cfg);

env_file = _Py_wfopen(tmpbuffer, L"r");

if (env_file == NULL) {

errno = 0;

}

}

if (env_file == NULL) {

return;

}

/* Look for a 'home' variable and set argv0_path to it, if found */

if (_Py_FindEnvConfigValue(env_file, L"home", tmpbuffer, MAXPATHLEN)) {

wcscpy(calculate->argv0_path, tmpbuffer);

}

fclose(env_file);

}

static void

calculate_zip_path(PyCalculatePath *calculate, const wchar_t *prefix)

{

wcsncpy(calculate->zip_path, prefix, MAXPATHLEN);

calculate->zip_path[MAXPATHLEN] = L'\0';

if (calculate->prefix_found > 0) {

/* Use the reduced prefix returned by Py_GetPrefix() */

reduce(calculate->zip_path);

reduce(calculate->zip_path);

}

else {

wcsncpy(calculate->zip_path, calculate->prefix, MAXPATHLEN);

}

joinpath(calculate->zip_path, L"lib/python00.zip");

/* Replace "00" with version */

size_t bufsz = wcslen(calculate->zip_path);

calculate->zip_path[bufsz - 6] = VERSION[0];

calculate->zip_path[bufsz - 5] = VERSION[2];

}

static _PyInitError

calculate_module_search_path(const _PyCoreConfig *core_config,

PyCalculatePath *calculate,

const wchar_t *prefix, const wchar_t *exec_prefix,

_PyPathConfig *config)

{

/* Calculate size of return buffer */

size_t bufsz = 0;

if (core_config->module_search_path_env != NULL) {

bufsz += wcslen(core_config->module_search_path_env) + 1;

}

wchar_t *defpath = calculate->pythonpath;

size_t prefixsz = wcslen(prefix) + 1;

while (1) {

wchar_t *delim = wcschr(defpath, DELIM);

if (defpath[0] != SEP) {

/* Paths are relative to prefix */

bufsz += prefixsz;

}

if (delim) {

bufsz += delim - defpath + 1;

}

else {

bufsz += wcslen(defpath) + 1;

break;

}

defpath = delim + 1;

}

bufsz += wcslen(calculate->zip_path) + 1;

bufsz += wcslen(exec_prefix) + 1;

/* Allocate the buffer */

wchar_t *buf = PyMem_RawMalloc(bufsz * sizeof(wchar_t));

if (buf == NULL) {

return _Py_INIT_NO_MEMORY();

}

buf[0] = '\0';

/* Run-time value of $PYTHONPATH goes first */

if (core_config->module_search_path_env) {

wcscpy(buf, core_config->module_search_path_env);

wcscat(buf, delimiter);

}

/* Next is the default zip path */

wcscat(buf, calculate->zip_path);

wcscat(buf, delimiter);

/* Next goes merge of compile-time $PYTHONPATH with

* dynamically located prefix.

*/

defpath = calculate->pythonpath;

while (1) {

wchar_t *delim = wcschr(defpath, DELIM);

if (defpath[0] != SEP) {

wcscat(buf, prefix);

if (prefixsz >= 2 && prefix[prefixsz - 2] != SEP &&

defpath[0] != (delim ? DELIM : L'\0'))

{

/* not empty */

wcscat(buf, separator);

}

}

if (delim) {

size_t len = delim - defpath + 1;

size_t end = wcslen(buf) + len;

wcsncat(buf, defpath, len);

buf[end] = '\0';

}

else {

wcscat(buf, defpath);

break;

}

defpath = delim + 1;

}

wcscat(buf, delimiter);

/* Finally, on goes the directory for dynamic-load modules */

wcscat(buf, exec_prefix);

config->module_search_path = buf;

return _Py_INIT_OK();

}

static _PyInitError

calculate_init(PyCalculatePath *calculate,

const _PyCoreConfig *core_config)

{

size_t len;

const char *path = getenv("PATH");

if (path) {

calculate->path_env = Py_DecodeLocale(path, &len);

if (!calculate->path_env) {

return DECODE_LOCALE_ERR("PATH environment variable", len);

}

}

calculate->pythonpath = Py_DecodeLocale(PYTHONPATH, &len);

if (!calculate->pythonpath) {

return DECODE_LOCALE_ERR("PYTHONPATH define", len);

}

calculate->prefix = Py_DecodeLocale(PREFIX, &len);

if (!calculate->prefix) {

return DECODE_LOCALE_ERR("PREFIX define", len);

}

calculate->exec_prefix = Py_DecodeLocale(EXEC_PREFIX, &len);

if (!calculate->prefix) {

return DECODE_LOCALE_ERR("EXEC_PREFIX define", len);

}

calculate->lib_python = Py_DecodeLocale("lib/python" VERSION, &len);

if (!calculate->lib_python) {

return DECODE_LOCALE_ERR("EXEC_PREFIX define", len);

}

return _Py_INIT_OK();

}

static void

calculate_free(PyCalculatePath *calculate)

{

PyMem_RawFree(calculate->pythonpath);

PyMem_RawFree(calculate->prefix);

PyMem_RawFree(calculate->exec_prefix);

PyMem_RawFree(calculate->lib_python);

PyMem_RawFree(calculate->path_env);

}

static _PyInitError

calculate_path_impl(const _PyCoreConfig *core_config,

PyCalculatePath *calculate, _PyPathConfig *config)

{

_PyInitError err;

err = calculate_program_full_path(core_config, calculate, config);

if (_Py_INIT_FAILED(err)) {

return err;

}

err = calculate_argv0_path(calculate, config->program_full_path);

if (_Py_INIT_FAILED(err)) {

return err;

}

calculate_read_pyenv(calculate);

wchar_t prefix[MAXPATHLEN+1];

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

calculate_prefix(core_config, calculate, prefix);

calculate_zip_path(calculate, prefix);

wchar_t exec_prefix[MAXPATHLEN+1];

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

calculate_exec_prefix(core_config, calculate, exec_prefix);

if ((!calculate->prefix_found || !calculate->exec_prefix_found) &&

!Py_FrozenFlag)

{

fprintf(stderr,

"Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]\n");

}

err = calculate_module_search_path(core_config, calculate,

prefix, exec_prefix, config);

if (_Py_INIT_FAILED(err)) {

return err;

}

calculate_reduce_prefix(calculate, prefix);

config->prefix = _PyMem_RawWcsdup(prefix);

if (config->prefix == NULL) {

return _Py_INIT_NO_MEMORY();

}

calculate_reduce_exec_prefix(calculate, exec_prefix);

config->exec_prefix = _PyMem_RawWcsdup(exec_prefix);

if (config->exec_prefix == NULL) {

return _Py_INIT_NO_MEMORY();

}

return _Py_INIT_OK();

}

_PyInitError

_PyPathConfig_Calculate(_PyPathConfig *config, const _PyCoreConfig *core_config)

{

PyCalculatePath calculate;

memset(&calculate, 0, sizeof(calculate));

_PyInitError err = calculate_init(&calculate, core_config);

if (_Py_INIT_FAILED(err)) {

goto done;

}

err = calculate_path_impl(core_config, &calculate, config);

if (_Py_INIT_FAILED(err)) {

goto done;

}

err = _Py_INIT_OK();

done:

calculate_free(&calculate);

return err;

}

#ifdef __cplusplus

}

#endif