/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:4;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=4 sts=4 sw=4 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Python 3 │
│ https://docs.python.org/3/license.html │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/calls.h"
#include "libc/calls/struct/stat.h"
#include "libc/errno.h"
#include "third_party/python/Include/fileutils.h"
#include "third_party/python/Include/osdefs.h"
#include "third_party/python/Include/pyerrors.h"
#include "third_party/python/Include/pymem.h"
/* clang-format off */
/* Return the initial module search path. */
#pragma GCC diagnostic ignored "-Wunused-function" // search_for_exec_prefix
#pragma GCC diagnostic ignored "-Wunused-but-set-variable" // separator
/* 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!
*/
wchar_t *Py_GetProgramName(void);
#if !defined(PREFIX) || !defined(EXEC_PREFIX) || !defined(VERSION) || !defined(VPATH)
#define PREFIX L"Lib"
#define EXEC_PREFIX L"build"
#define VERSION L"3.6"
#define VPATH ""
// #error "PREFIX, EXEC_PREFIX, VERSION, and VPATH must be constant defined"
#endif
#ifndef LANDMARK
#define LANDMARK L"os.py"
#endif
static wchar_t prefix[MAXPATHLEN+1];
static wchar_t exec_prefix[MAXPATHLEN+1];
static wchar_t progpath[MAXPATHLEN+1];
static wchar_t *module_search_path = NULL;
/* 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_EncodeLocale(path, NULL);
if (fname == NULL) {
errno = EINVAL;
return -1;
}
err = stat(fname, buf);
PyMem_Free(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;
}
static int
isxfile(wchar_t *filename) /* Is executable file */
{
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;
}
static int
isdir(wchar_t *filename) /* Is directory */
{
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 a prefix value in an environment file. If found, copy it
to the provided buffer, which is expected to be no more than MAXPATHLEN
bytes long.
*/
static int
find_env_config_value(FILE * env_file, const wchar_t * key, wchar_t * value)
{
int result = 0; /* meaning not found */
char buffer[MAXPATHLEN*2+1]; /* allow extra for key, '=', etc. */
fseek(env_file, 0, SEEK_SET);
while (!feof(env_file)) {
char * p = fgets(buffer, MAXPATHLEN*2, env_file);
wchar_t tmpbuffer[MAXPATHLEN*2+1];
PyObject * decoded;
int n;
if (p == NULL)
break;
n = strlen(p);
if (p[n - 1] != '\n') {
/* line has overflowed - bail */
break;
}
if (p[0] == '#') /* Comment - skip */
continue;
decoded = PyUnicode_DecodeUTF8(buffer, n, "surrogateescape");
if (decoded != NULL) {
Py_ssize_t k;
wchar_t * state;
k = PyUnicode_AsWideChar(decoded,
tmpbuffer, MAXPATHLEN * 2);
Py_DECREF(decoded);
if (k >= 0) {
wchar_t * tok = wcstok(tmpbuffer, L" \t\r\n", &state);
if ((tok != NULL) && !wcscmp(tok, key)) {
tok = wcstok(NULL, L" \t", &state);
if ((tok != NULL) && !wcscmp(tok, L"=")) {
tok = wcstok(NULL, L"\r\n", &state);
if (tok != NULL) {
wcsncpy(value, tok, MAXPATHLEN);
result = 1;
break;
}
}
}
}
}
}
return result;
}
/* search_for_prefix requires that argv0_path be no more than MAXPATHLEN
bytes long.
*/
static int
search_for_prefix(wchar_t *argv0_path, wchar_t *home, wchar_t *_prefix,
wchar_t *lib_python)
{
size_t n;
wchar_t *vpath;
/* If PYTHONHOME is set, we believe it unconditionally */
if (home) {
wchar_t *delim;
wcsncpy(prefix, home, MAXPATHLEN);
prefix[MAXPATHLEN] = L'\0';
delim = wcschr(prefix, DELIM);
if (delim)
*delim = L'\0';
joinpath(prefix, lib_python);
joinpath(prefix, LANDMARK);
return 1;
}
/* Check to see if argv[0] is in the build directory */
wcsncpy(prefix, 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, 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, argv0_path, MAXPATHLEN+1);
do {
n = wcslen(prefix);
joinpath(prefix, 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, _prefix, MAXPATHLEN);
prefix[MAXPATHLEN] = L'\0';
joinpath(prefix, lib_python);
joinpath(prefix, LANDMARK);
if (ismodule(prefix))
return 1;
/* Fail */
return 0;
}
/* search_for_exec_prefix requires that argv0_path be no more than
MAXPATHLEN bytes long.
*/
static int
search_for_exec_prefix(wchar_t *argv0_path, wchar_t *home,
wchar_t *_exec_prefix, wchar_t *lib_python)
{
size_t n;
/* If PYTHONHOME is set, we believe it unconditionally */
if (home) {
wchar_t *delim;
delim = wcschr(home, DELIM);
if (delim)
wcsncpy(exec_prefix, delim+1, MAXPATHLEN);
else
wcsncpy(exec_prefix, home, MAXPATHLEN);
exec_prefix[MAXPATHLEN] = L'\0';
joinpath(exec_prefix, 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, 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];
PyObject *decoded;
wchar_t rel_builddir_path[MAXPATHLEN+1];
n = fread(buf, 1, MAXPATHLEN, f);
buf[n] = '\0';
fclose(f);
decoded = PyUnicode_DecodeUTF8(buf, n, "surrogateescape");
if (decoded != NULL) {
Py_ssize_t k;
k = PyUnicode_AsWideChar(decoded,
rel_builddir_path, MAXPATHLEN);
Py_DECREF(decoded);
if (k >= 0) {
rel_builddir_path[k] = L'\0';
wcsncpy(exec_prefix, argv0_path, MAXPATHLEN);
exec_prefix[MAXPATHLEN] = L'\0';
joinpath(exec_prefix, rel_builddir_path);
return -1;
}
}
}
}
/* Search from argv0_path, until root is found */
copy_absolute(exec_prefix, argv0_path, MAXPATHLEN+1);
do {
n = wcslen(exec_prefix);
joinpath(exec_prefix, 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, _exec_prefix, MAXPATHLEN);
exec_prefix[MAXPATHLEN] = L'\0';
joinpath(exec_prefix, lib_python);
joinpath(exec_prefix, L"lib-dynload");
if (isdir(exec_prefix))
return 1;
/* Fail */
return 0;
}
static void
calculate_path(void)
{
#if 0
static wchar_t delimiter[2] = {DELIM, '\0'};
static wchar_t separator[2] = {SEP, '\0'};
/* ignore PYTHONPATH/PYTHONHOME for now */
// char *_rtpypath = Py_GETENV("PYTHONPATH");
/* XXX use wide version on Windows */
// wchar_t *rtpypath = NULL;
// wchar_t *home = Py_GetPythonHome();
char *_path = getenv("PATH");
wchar_t *path_buffer = NULL;
wchar_t *path = NULL;
wchar_t *prog = Py_GetProgramName();
wchar_t argv0_path[MAXPATHLEN+1];
/* wont need zip_path because embedded stdlib inside executable */
/* wchar_t zip_path[MAXPATHLEN+1]; */
wchar_t *buf;
size_t bufsz;
wchar_t ape_path[MAXPATHLEN+1];
size_t ape_length;
wchar_t ape_lib_path[MAXPATHLEN+1];
wchar_t ape_exec_path[MAXPATHLEN+1];
wchar_t package_path[MAXPATHLEN+1];
wchar_t ape_package_path[MAXPATHLEN+1];
if(IsWindows())
{
delimiter[0] = L';';
separator[0] = L'\\';
}
if (_path) {
path_buffer = Py_DecodeLocale(_path, NULL);
path = path_buffer;
}
/* 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(prog, SEP))
wcsncpy(progpath, prog, MAXPATHLEN);
else if (path) {
while (1) {
wchar_t *delim = wcschr(path, DELIM);
if (delim) {
size_t len = delim - path;
if (len > MAXPATHLEN)
len = MAXPATHLEN;
wcsncpy(progpath, path, len);
*(progpath + len) = '\0';
}
else
wcsncpy(progpath, path, MAXPATHLEN);
joinpath(progpath, prog);
if (isxfile(progpath))
break;
if (!delim) {
progpath[0] = L'\0';
break;
}
path = delim + 1;
}
}
else
progpath[0] = '\0';
PyMem_RawFree(path_buffer);
if (progpath[0] != SEP && progpath[0] != '\0')
absolutize(progpath);
wcsncpy(argv0_path, progpath, MAXPATHLEN);
argv0_path[MAXPATHLEN] = '\0';
reduce(argv0_path);
/* At this point, argv0_path is guaranteed to be less than
MAXPATHLEN bytes long.
*/
/* not searching for pyvenv.cfg */
/* Avoid absolute path for prefix */
wcsncpy(prefix,
L"third_party/python/Lib",
MAXPATHLEN);
wcsncpy(prefix,
L"zip!.python",
MAXPATHLEN);
/* Avoid absolute path for exec_prefix */
wcsncpy(exec_prefix, L"build/lib.linux-x86_64-3.6", MAXPATHLEN);
wcsncpy(package_path, L"Lib/site-packages", MAXPATHLEN);
// printf("progpath = %ls, prog = %ls\n", progpath, prog);
/* add paths for the internal store of the APE */
if(wcslen(progpath) > 0 && wcslen(progpath) + 1 < MAXPATHLEN)
wcsncpy(ape_path, progpath, MAXPATHLEN);
else
wcsncpy(ape_path, prog, MAXPATHLEN);
ape_length = wcslen(ape_path);
wcsncpy(ape_lib_path, ape_path, MAXPATHLEN);
// extra 1 at the start for the slash
if(ape_length + 1 + wcslen(prefix) + 1 < MAXPATHLEN)
{
ape_lib_path[ape_length] = L'/';
wcscat(ape_lib_path + ape_length + 1, prefix);
}
wcsncpy(ape_exec_path, ape_path, MAXPATHLEN);
if(ape_length + 1 + wcslen(exec_prefix) + 1 < MAXPATHLEN)
{
ape_exec_path[ape_length] = L'/';
wcscat(ape_exec_path + ape_length + 1, exec_prefix);
}
wcsncpy(ape_package_path, ape_path, MAXPATHLEN);
if(ape_length + 1 + wcslen(package_path) + 1 < MAXPATHLEN)
{
ape_package_path[ape_length] = L'/';
wcscat(ape_package_path + ape_length + 1, package_path);
}
/* Calculate size of return buffer */
bufsz = 0;
bufsz += wcslen(ape_lib_path) + 1;
bufsz += wcslen(ape_exec_path) + 1;
bufsz += wcslen(ape_package_path) + 1;
bufsz += wcslen(ape_path) + 1;
bufsz += wcslen(prefix) + 1;
bufsz += wcslen(exec_prefix) + 1;
bufsz += wcslen(package_path) + 1;
/* This is the only malloc call in this file */
buf = PyMem_RawMalloc(bufsz * sizeof(wchar_t));
if (buf == NULL) {
Py_FatalError(
"Not enough memory for dynamic PYTHONPATH");
}
buf[0] = L'\0';
wcscat(buf, prefix);
wcscat(buf, delimiter);
wcscat(buf, package_path);
wcscat(buf, delimiter);
wcscat(buf, ape_lib_path);
wcscat(buf, delimiter);
wcscat(buf, ape_package_path);
wcscat(buf, delimiter);
wcscat(buf, ape_exec_path);
wcscat(buf, delimiter);
wcscat(buf, ape_path);
wcscat(buf, delimiter);
/* Finally, on goes the directory for dynamic-load modules */
wcscat(buf, exec_prefix);
/* And publish the results */
module_search_path = buf;
// printf("%ls\n", buf);
#else
module_search_path = L"zip!.python/";
/* module_search_path = L"third_party/python/Lib/"; */
#endif
}
/* External interface */
void
Py_SetPath(const wchar_t *path)
{
if (module_search_path != NULL) {
PyMem_RawFree(module_search_path);
module_search_path = NULL;
}
if (path != NULL) {
wchar_t *prog = Py_GetProgramName();
wcsncpy(progpath, prog, MAXPATHLEN);
exec_prefix[0] = prefix[0] = L'\0';
module_search_path = PyMem_RawMalloc((wcslen(path) + 1) * sizeof(wchar_t));
if (module_search_path != NULL)
wcscpy(module_search_path, path);
}
}
wchar_t *
Py_GetPath(void)
{
if (!module_search_path)
calculate_path();
return module_search_path;
}
wchar_t *
Py_GetPrefix(void)
{
if (!module_search_path)
calculate_path();
return prefix;
}
wchar_t *
Py_GetExecPrefix(void)
{
if (!module_search_path)
calculate_path();
return exec_prefix;
}
wchar_t *
Py_GetProgramFullPath(void)
{
if (!module_search_path)
calculate_path();
return progpath;
}