cpython/Python/pathconfig.c
Eric Snow 0c50b8c0b8
bpo-45211: Remember the stdlib dir during startup. (gh-28586)
During runtime startup we figure out the stdlib dir but currently throw that information away. This change preserves it and exposes it via PyConfig.stdlib_dir, _Py_GetStdlibDir(), and sys._stdlib_dir.

https://bugs.python.org/issue45211
2021-09-28 12:18:28 -06:00

848 lines
21 KiB
C

/* Path configuration like module_search_path (sys.path) */
#include "Python.h"
#include "osdefs.h" // DELIM
#include "pycore_initconfig.h"
#include "pycore_fileutils.h"
#include "pycore_pathconfig.h"
#include "pycore_pymem.h" // _PyMem_SetDefaultAllocator()
#include <wchar.h>
#ifdef MS_WINDOWS
# include <windows.h> // GetFullPathNameW(), MAX_PATH
#endif
#ifdef __cplusplus
extern "C" {
#endif
_PyPathConfig _Py_path_config = _PyPathConfig_INIT;
static int
copy_wstr(wchar_t **dst, const wchar_t *src)
{
assert(*dst == NULL);
if (src != NULL) {
*dst = _PyMem_RawWcsdup(src);
if (*dst == NULL) {
return -1;
}
}
else {
*dst = NULL;
}
return 0;
}
static void
pathconfig_clear(_PyPathConfig *config)
{
/* _PyMem_SetDefaultAllocator() is needed to get a known memory allocator,
since Py_SetPath(), Py_SetPythonHome() and Py_SetProgramName() can be
called before Py_Initialize() which can changes the memory allocator. */
PyMemAllocatorEx old_alloc;
_PyMem_SetDefaultAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
#define CLEAR(ATTR) \
do { \
PyMem_RawFree(ATTR); \
ATTR = NULL; \
} while (0)
CLEAR(config->program_full_path);
CLEAR(config->prefix);
CLEAR(config->exec_prefix);
CLEAR(config->stdlib_dir);
CLEAR(config->module_search_path);
CLEAR(config->program_name);
CLEAR(config->home);
#ifdef MS_WINDOWS
CLEAR(config->base_executable);
#endif
#undef CLEAR
PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
}
static PyStatus
pathconfig_copy(_PyPathConfig *config, const _PyPathConfig *config2)
{
pathconfig_clear(config);
#define COPY_ATTR(ATTR) \
do { \
if (copy_wstr(&config->ATTR, config2->ATTR) < 0) { \
return _PyStatus_NO_MEMORY(); \
} \
} while (0)
COPY_ATTR(program_full_path);
COPY_ATTR(prefix);
COPY_ATTR(exec_prefix);
COPY_ATTR(module_search_path);
COPY_ATTR(stdlib_dir);
COPY_ATTR(program_name);
COPY_ATTR(home);
#ifdef MS_WINDOWS
config->isolated = config2->isolated;
config->site_import = config2->site_import;
COPY_ATTR(base_executable);
#endif
#undef COPY_ATTR
return _PyStatus_OK();
}
void
_PyPathConfig_ClearGlobal(void)
{
PyMemAllocatorEx old_alloc;
_PyMem_SetDefaultAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
pathconfig_clear(&_Py_path_config);
PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
}
static wchar_t*
_PyWideStringList_Join(const PyWideStringList *list, wchar_t sep)
{
size_t len = 1; /* NUL terminator */
for (Py_ssize_t i=0; i < list->length; i++) {
if (i != 0) {
len++;
}
len += wcslen(list->items[i]);
}
wchar_t *text = PyMem_RawMalloc(len * sizeof(wchar_t));
if (text == NULL) {
return NULL;
}
wchar_t *str = text;
for (Py_ssize_t i=0; i < list->length; i++) {
wchar_t *path = list->items[i];
if (i != 0) {
*str++ = sep;
}
len = wcslen(path);
memcpy(str, path, len * sizeof(wchar_t));
str += len;
}
*str = L'\0';
return text;
}
static PyStatus
pathconfig_set_from_config(_PyPathConfig *pathconfig, const PyConfig *config)
{
PyStatus status;
PyMemAllocatorEx old_alloc;
_PyMem_SetDefaultAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
if (config->module_search_paths_set) {
PyMem_RawFree(pathconfig->module_search_path);
pathconfig->module_search_path = _PyWideStringList_Join(&config->module_search_paths, DELIM);
if (pathconfig->module_search_path == NULL) {
goto no_memory;
}
}
#define COPY_CONFIG(PATH_ATTR, CONFIG_ATTR) \
if (config->CONFIG_ATTR) { \
PyMem_RawFree(pathconfig->PATH_ATTR); \
pathconfig->PATH_ATTR = NULL; \
if (copy_wstr(&pathconfig->PATH_ATTR, config->CONFIG_ATTR) < 0) { \
goto no_memory; \
} \
}
COPY_CONFIG(program_full_path, executable);
COPY_CONFIG(prefix, prefix);
COPY_CONFIG(exec_prefix, exec_prefix);
COPY_CONFIG(stdlib_dir, stdlib_dir);
COPY_CONFIG(program_name, program_name);
COPY_CONFIG(home, home);
#ifdef MS_WINDOWS
COPY_CONFIG(base_executable, base_executable);
#endif
#undef COPY_CONFIG
status = _PyStatus_OK();
goto done;
no_memory:
status = _PyStatus_NO_MEMORY();
done:
PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
return status;
}
PyObject *
_PyPathConfig_AsDict(void)
{
PyObject *dict = PyDict_New();
if (dict == NULL) {
return NULL;
}
#define SET_ITEM(KEY, EXPR) \
do { \
PyObject *obj = (EXPR); \
if (obj == NULL) { \
goto fail; \
} \
int res = PyDict_SetItemString(dict, KEY, obj); \
Py_DECREF(obj); \
if (res < 0) { \
goto fail; \
} \
} while (0)
#define SET_ITEM_STR(KEY) \
SET_ITEM(#KEY, \
(_Py_path_config.KEY \
? PyUnicode_FromWideChar(_Py_path_config.KEY, -1) \
: (Py_INCREF(Py_None), Py_None)))
#define SET_ITEM_INT(KEY) \
SET_ITEM(#KEY, PyLong_FromLong(_Py_path_config.KEY))
SET_ITEM_STR(program_full_path);
SET_ITEM_STR(prefix);
SET_ITEM_STR(exec_prefix);
SET_ITEM_STR(module_search_path);
SET_ITEM_STR(stdlib_dir);
SET_ITEM_STR(program_name);
SET_ITEM_STR(home);
#ifdef MS_WINDOWS
SET_ITEM_INT(isolated);
SET_ITEM_INT(site_import);
SET_ITEM_STR(base_executable);
{
wchar_t py3path[MAX_PATH];
HMODULE hPython3 = GetModuleHandleW(PY3_DLLNAME);
PyObject *obj;
if (hPython3
&& GetModuleFileNameW(hPython3, py3path, Py_ARRAY_LENGTH(py3path)))
{
obj = PyUnicode_FromWideChar(py3path, -1);
if (obj == NULL) {
goto fail;
}
}
else {
obj = Py_None;
Py_INCREF(obj);
}
if (PyDict_SetItemString(dict, "python3_dll", obj) < 0) {
Py_DECREF(obj);
goto fail;
}
Py_DECREF(obj);
}
#endif
#undef SET_ITEM
#undef SET_ITEM_STR
#undef SET_ITEM_INT
return dict;
fail:
Py_DECREF(dict);
return NULL;
}
PyStatus
_PyConfig_WritePathConfig(const PyConfig *config)
{
return pathconfig_set_from_config(&_Py_path_config, config);
}
static PyStatus
config_init_module_search_paths(PyConfig *config, _PyPathConfig *pathconfig)
{
assert(!config->module_search_paths_set);
_PyWideStringList_Clear(&config->module_search_paths);
const wchar_t *sys_path = pathconfig->module_search_path;
const wchar_t delim = DELIM;
while (1) {
const wchar_t *p = wcschr(sys_path, delim);
if (p == NULL) {
p = sys_path + wcslen(sys_path); /* End of string */
}
size_t path_len = (p - sys_path);
wchar_t *path = PyMem_RawMalloc((path_len + 1) * sizeof(wchar_t));
if (path == NULL) {
return _PyStatus_NO_MEMORY();
}
memcpy(path, sys_path, path_len * sizeof(wchar_t));
path[path_len] = L'\0';
PyStatus status = PyWideStringList_Append(&config->module_search_paths, path);
PyMem_RawFree(path);
if (_PyStatus_EXCEPTION(status)) {
return status;
}
if (*p == '\0') {
break;
}
sys_path = p + 1;
}
config->module_search_paths_set = 1;
return _PyStatus_OK();
}
/* Calculate the path configuration:
- exec_prefix
- module_search_path
- stdlib_dir
- prefix
- program_full_path
On Windows, more fields are calculated:
- base_executable
- isolated
- site_import
On other platforms, isolated and site_import are left unchanged, and
_PyConfig_InitPathConfig() copies executable to base_executable (if it's not
set).
Priority, highest to lowest:
- PyConfig
- _Py_path_config: set by Py_SetPath(), Py_SetPythonHome()
and Py_SetProgramName()
- _PyPathConfig_Calculate()
*/
static PyStatus
pathconfig_init(_PyPathConfig *pathconfig, const PyConfig *config,
int compute_path_config)
{
PyStatus status;
PyMemAllocatorEx old_alloc;
_PyMem_SetDefaultAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
status = pathconfig_copy(pathconfig, &_Py_path_config);
if (_PyStatus_EXCEPTION(status)) {
goto done;
}
status = pathconfig_set_from_config(pathconfig, config);
if (_PyStatus_EXCEPTION(status)) {
goto done;
}
if (compute_path_config) {
status = _PyPathConfig_Calculate(pathconfig, config);
}
done:
PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
return status;
}
static PyStatus
config_init_pathconfig(PyConfig *config, int compute_path_config)
{
_PyPathConfig pathconfig = _PyPathConfig_INIT;
PyStatus status;
status = pathconfig_init(&pathconfig, config, compute_path_config);
if (_PyStatus_EXCEPTION(status)) {
goto done;
}
if (!config->module_search_paths_set
&& pathconfig.module_search_path != NULL)
{
status = config_init_module_search_paths(config, &pathconfig);
if (_PyStatus_EXCEPTION(status)) {
goto done;
}
}
#define COPY_ATTR(PATH_ATTR, CONFIG_ATTR) \
if (config->CONFIG_ATTR == NULL && pathconfig.PATH_ATTR != NULL) { \
if (copy_wstr(&config->CONFIG_ATTR, pathconfig.PATH_ATTR) < 0) { \
goto no_memory; \
} \
}
#ifdef MS_WINDOWS
if (config->executable != NULL && config->base_executable == NULL) {
/* If executable is set explicitly in the configuration,
ignore calculated base_executable: _PyConfig_InitPathConfig()
will copy executable to base_executable */
}
else {
COPY_ATTR(base_executable, base_executable);
}
#endif
COPY_ATTR(program_full_path, executable);
COPY_ATTR(prefix, prefix);
COPY_ATTR(exec_prefix, exec_prefix);
COPY_ATTR(stdlib_dir, stdlib_dir);
#undef COPY_ATTR
#ifdef MS_WINDOWS
/* If a ._pth file is found: isolated and site_import are overriden */
if (pathconfig.isolated != -1) {
config->isolated = pathconfig.isolated;
}
if (pathconfig.site_import != -1) {
config->site_import = pathconfig.site_import;
}
#endif
status = _PyStatus_OK();
goto done;
no_memory:
status = _PyStatus_NO_MEMORY();
done:
pathconfig_clear(&pathconfig);
return status;
}
PyStatus
_PyConfig_InitPathConfig(PyConfig *config, int compute_path_config)
{
/* Do we need to calculate the path? */
if (!config->module_search_paths_set
|| config->executable == NULL
|| config->prefix == NULL
|| config->exec_prefix == NULL)
{
PyStatus status = config_init_pathconfig(config, compute_path_config);
if (_PyStatus_EXCEPTION(status)) {
return status;
}
}
if (config->base_prefix == NULL && config->prefix != NULL) {
if (copy_wstr(&config->base_prefix, config->prefix) < 0) {
return _PyStatus_NO_MEMORY();
}
}
if (config->base_exec_prefix == NULL && config->exec_prefix != NULL) {
if (copy_wstr(&config->base_exec_prefix,
config->exec_prefix) < 0) {
return _PyStatus_NO_MEMORY();
}
}
if (config->base_executable == NULL && config->executable != NULL) {
if (copy_wstr(&config->base_executable,
config->executable) < 0) {
return _PyStatus_NO_MEMORY();
}
}
return _PyStatus_OK();
}
/* External interface */
static void _Py_NO_RETURN
path_out_of_memory(const char *func)
{
_Py_FatalErrorFunc(func, "out of memory");
}
void
Py_SetPath(const wchar_t *path)
{
if (path == NULL) {
pathconfig_clear(&_Py_path_config);
return;
}
PyMemAllocatorEx old_alloc;
_PyMem_SetDefaultAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
PyMem_RawFree(_Py_path_config.prefix);
PyMem_RawFree(_Py_path_config.exec_prefix);
PyMem_RawFree(_Py_path_config.stdlib_dir);
PyMem_RawFree(_Py_path_config.module_search_path);
_Py_path_config.prefix = _PyMem_RawWcsdup(L"");
_Py_path_config.exec_prefix = _PyMem_RawWcsdup(L"");
// XXX Copy this from the new module_search_path?
if (_Py_path_config.home != NULL) {
_Py_path_config.stdlib_dir = _PyMem_RawWcsdup(_Py_path_config.home);
}
else {
_Py_path_config.stdlib_dir = _PyMem_RawWcsdup(L"");
}
_Py_path_config.module_search_path = _PyMem_RawWcsdup(path);
PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
if (_Py_path_config.prefix == NULL
|| _Py_path_config.exec_prefix == NULL
|| _Py_path_config.stdlib_dir == NULL
|| _Py_path_config.module_search_path == NULL)
{
path_out_of_memory(__func__);
}
}
void
Py_SetPythonHome(const wchar_t *home)
{
if (home == NULL) {
return;
}
PyMemAllocatorEx old_alloc;
_PyMem_SetDefaultAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
PyMem_RawFree(_Py_path_config.home);
_Py_path_config.home = _PyMem_RawWcsdup(home);
if (_Py_path_config.home != NULL) {
_Py_path_config.stdlib_dir = _PyMem_RawWcsdup(home);
}
PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
if (_Py_path_config.home == NULL || _Py_path_config.stdlib_dir == NULL) {
path_out_of_memory(__func__);
}
}
void
Py_SetProgramName(const wchar_t *program_name)
{
if (program_name == NULL || program_name[0] == L'\0') {
return;
}
PyMemAllocatorEx old_alloc;
_PyMem_SetDefaultAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
PyMem_RawFree(_Py_path_config.program_name);
_Py_path_config.program_name = _PyMem_RawWcsdup(program_name);
PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
if (_Py_path_config.program_name == NULL) {
path_out_of_memory(__func__);
}
}
void
_Py_SetProgramFullPath(const wchar_t *program_full_path)
{
if (program_full_path == NULL || program_full_path[0] == L'\0') {
return;
}
PyMemAllocatorEx old_alloc;
_PyMem_SetDefaultAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
PyMem_RawFree(_Py_path_config.program_full_path);
_Py_path_config.program_full_path = _PyMem_RawWcsdup(program_full_path);
PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
if (_Py_path_config.program_full_path == NULL) {
path_out_of_memory(__func__);
}
}
wchar_t *
Py_GetPath(void)
{
return _Py_path_config.module_search_path;
}
wchar_t *
_Py_GetStdlibDir(void)
{
wchar_t *stdlib_dir = _Py_path_config.stdlib_dir;
if (stdlib_dir != NULL && stdlib_dir[0] != L'\0') {
return stdlib_dir;
}
return NULL;
}
wchar_t *
Py_GetPrefix(void)
{
return _Py_path_config.prefix;
}
wchar_t *
Py_GetExecPrefix(void)
{
return _Py_path_config.exec_prefix;
}
wchar_t *
Py_GetProgramFullPath(void)
{
return _Py_path_config.program_full_path;
}
wchar_t*
Py_GetPythonHome(void)
{
return _Py_path_config.home;
}
wchar_t *
Py_GetProgramName(void)
{
return _Py_path_config.program_name;
}
/* Compute module search path from argv[0] or the current working
directory ("-m module" case) which will be prepended to sys.argv:
sys.path[0].
Return 1 if the path is correctly resolved and written into *path0_p.
Return 0 if it fails to resolve the full path. For example, return 0 if the
current working directory has been removed (bpo-36236) or if argv is empty.
Raise an exception and return -1 on error.
*/
int
_PyPathConfig_ComputeSysPath0(const PyWideStringList *argv, PyObject **path0_p)
{
assert(_PyWideStringList_CheckConsistency(argv));
if (argv->length == 0) {
/* Leave sys.path unchanged if sys.argv is empty */
return 0;
}
wchar_t *argv0 = argv->items[0];
int have_module_arg = (wcscmp(argv0, L"-m") == 0);
int have_script_arg = (!have_module_arg && (wcscmp(argv0, L"-c") != 0));
wchar_t *path0 = argv0;
Py_ssize_t n = 0;
#ifdef HAVE_REALPATH
wchar_t fullpath[MAXPATHLEN];
#elif defined(MS_WINDOWS)
wchar_t fullpath[MAX_PATH];
#endif
if (have_module_arg) {
#if defined(HAVE_REALPATH) || defined(MS_WINDOWS)
if (!_Py_wgetcwd(fullpath, Py_ARRAY_LENGTH(fullpath))) {
return 0;
}
path0 = fullpath;
#else
path0 = L".";
#endif
n = wcslen(path0);
}
#ifdef HAVE_READLINK
wchar_t link[MAXPATHLEN + 1];
int nr = 0;
wchar_t path0copy[2 * MAXPATHLEN + 1];
if (have_script_arg) {
nr = _Py_wreadlink(path0, link, Py_ARRAY_LENGTH(link));
}
if (nr > 0) {
/* It's a symlink */
link[nr] = '\0';
if (link[0] == SEP) {
path0 = link; /* Link to absolute path */
}
else if (wcschr(link, SEP) == NULL) {
/* Link without path */
}
else {
/* Must join(dirname(path0), link) */
wchar_t *q = wcsrchr(path0, SEP);
if (q == NULL) {
/* path0 without path */
path0 = link;
}
else {
/* Must make a copy, path0copy has room for 2 * MAXPATHLEN */
wcsncpy(path0copy, path0, MAXPATHLEN);
q = wcsrchr(path0copy, SEP);
wcsncpy(q+1, link, MAXPATHLEN);
q[MAXPATHLEN + 1] = L'\0';
path0 = path0copy;
}
}
}
#endif /* HAVE_READLINK */
wchar_t *p = NULL;
#if SEP == '\\'
/* Special case for Microsoft filename syntax */
if (have_script_arg) {
wchar_t *q;
#if defined(MS_WINDOWS)
/* Replace the first element in argv with the full path. */
wchar_t *ptemp;
if (GetFullPathNameW(path0,
Py_ARRAY_LENGTH(fullpath),
fullpath,
&ptemp)) {
path0 = fullpath;
}
#endif
p = wcsrchr(path0, SEP);
/* Test for alternate separator */
q = wcsrchr(p ? p : path0, '/');
if (q != NULL)
p = q;
if (p != NULL) {
n = p + 1 - path0;
if (n > 1 && p[-1] != ':')
n--; /* Drop trailing separator */
}
}
#else
/* All other filename syntaxes */
if (have_script_arg) {
#if defined(HAVE_REALPATH)
if (_Py_wrealpath(path0, fullpath, Py_ARRAY_LENGTH(fullpath))) {
path0 = fullpath;
}
#endif
p = wcsrchr(path0, SEP);
}
if (p != NULL) {
n = p + 1 - path0;
#if SEP == '/' /* Special case for Unix filename syntax */
if (n > 1) {
/* Drop trailing separator */
n--;
}
#endif /* Unix */
}
#endif /* All others */
PyObject *path0_obj = PyUnicode_FromWideChar(path0, n);
if (path0_obj == NULL) {
return -1;
}
*path0_p = path0_obj;
return 1;
}
#ifdef MS_WINDOWS
#define WCSTOK wcstok_s
#else
#define WCSTOK wcstok
#endif
/* Search for a prefix value in an environment file (pyvenv.cfg).
- If found, copy it into *value_p: string which must be freed by
PyMem_RawFree().
- If not found, *value_p is set to NULL.
*/
PyStatus
_Py_FindEnvConfigValue(FILE *env_file, const wchar_t *key,
wchar_t **value_p)
{
*value_p = NULL;
char buffer[MAXPATHLEN * 2 + 1]; /* allow extra for key, '=', etc. */
buffer[Py_ARRAY_LENGTH(buffer)-1] = '\0';
while (!feof(env_file)) {
char * p = fgets(buffer, Py_ARRAY_LENGTH(buffer) - 1, env_file);
if (p == NULL) {
break;
}
size_t n = strlen(p);
if (p[n - 1] != '\n') {
/* line has overflowed - bail */
break;
}
if (p[0] == '#') {
/* Comment - skip */
continue;
}
wchar_t *tmpbuffer = _Py_DecodeUTF8_surrogateescape(buffer, n, NULL);
if (tmpbuffer) {
wchar_t * state;
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) {
*value_p = _PyMem_RawWcsdup(tok);
PyMem_RawFree(tmpbuffer);
if (*value_p == NULL) {
return _PyStatus_NO_MEMORY();
}
/* found */
return _PyStatus_OK();
}
}
}
PyMem_RawFree(tmpbuffer);
}
}
/* not found */
return _PyStatus_OK();
}
#ifdef __cplusplus
}
#endif