cpython/Python/pathconfig.c
Victor Stinner fc96e5474a
bpo-36236: Fix _PyPathConfig_ComputeSysPath0() for empty argv (GH-12441)
* _PyPathConfig_ComputeSysPath0() now returns 0 if argv is empty.
* Cleanup also _PyPathConfig_ComputeSysPath0() code: move variables
  definitions closer to where they are used.
2019-03-19 18:22:55 +01:00

765 lines
19 KiB
C

/* Path configuration like module_search_path (sys.path) */
#include "Python.h"
#include "osdefs.h"
#include "pycore_coreconfig.h"
#include "pycore_fileutils.h"
#include "pycore_pathconfig.h"
#include "pycore_pymem.h"
#include "pycore_pystate.h"
#include <wchar.h>
#ifdef __cplusplus
extern "C" {
#endif
_PyPathConfig _Py_path_config = _PyPathConfig_INIT;
static int
copy_wstr(wchar_t **dst, const wchar_t *src)
{
if (src != NULL) {
*dst = _PyMem_RawWcsdup(src);
if (*dst == NULL) {
return -1;
}
}
else {
*dst = NULL;
}
return 0;
}
static void
_PyPathConfig_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->prefix);
CLEAR(config->program_full_path);
CLEAR(config->exec_prefix);
#ifdef MS_WINDOWS
CLEAR(config->dll_path);
#endif
CLEAR(config->module_search_path);
CLEAR(config->home);
CLEAR(config->program_name);
#undef CLEAR
PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
}
/* Calculate the path configuration: initialize path_config from core_config */
static _PyInitError
_PyPathConfig_Calculate(_PyPathConfig *path_config,
const _PyCoreConfig *core_config)
{
_PyInitError err;
_PyPathConfig new_config = _PyPathConfig_INIT;
PyMemAllocatorEx old_alloc;
_PyMem_SetDefaultAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
/* Calculate program_full_path, prefix, exec_prefix,
dll_path (Windows), and module_search_path */
err = _PyPathConfig_Calculate_impl(&new_config, core_config);
if (_Py_INIT_FAILED(err)) {
goto err;
}
/* Copy home and program_name from core_config */
if (copy_wstr(&new_config.home, core_config->home) < 0) {
err = _Py_INIT_NO_MEMORY();
goto err;
}
if (copy_wstr(&new_config.program_name, core_config->program_name) < 0) {
err = _Py_INIT_NO_MEMORY();
goto err;
}
_PyPathConfig_Clear(path_config);
*path_config = new_config;
err = _Py_INIT_OK();
goto done;
err:
_PyPathConfig_Clear(&new_config);
done:
PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
return err;
}
_PyInitError
_PyPathConfig_SetGlobal(const _PyPathConfig *config)
{
_PyInitError err;
_PyPathConfig new_config = _PyPathConfig_INIT;
PyMemAllocatorEx old_alloc;
_PyMem_SetDefaultAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
#define COPY_ATTR(ATTR) \
do { \
if (copy_wstr(&new_config.ATTR, config->ATTR) < 0) { \
_PyPathConfig_Clear(&new_config); \
err = _Py_INIT_NO_MEMORY(); \
goto done; \
} \
} while (0)
COPY_ATTR(program_full_path);
COPY_ATTR(prefix);
COPY_ATTR(exec_prefix);
#ifdef MS_WINDOWS
COPY_ATTR(dll_path);
#endif
COPY_ATTR(module_search_path);
COPY_ATTR(program_name);
COPY_ATTR(home);
_PyPathConfig_Clear(&_Py_path_config);
/* Steal new_config strings; don't clear new_config */
_Py_path_config = new_config;
err = _Py_INIT_OK();
done:
PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
return err;
}
void
_PyPathConfig_ClearGlobal(void)
{
PyMemAllocatorEx old_alloc;
_PyMem_SetDefaultAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
_PyPathConfig_Clear(&_Py_path_config);
PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
}
static wchar_t*
_PyWstrList_Join(const _PyWstrList *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;
}
/* Set the global path configuration from core_config. */
_PyInitError
_PyCoreConfig_SetPathConfig(const _PyCoreConfig *core_config)
{
PyMemAllocatorEx old_alloc;
_PyMem_SetDefaultAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
_PyInitError err;
_PyPathConfig path_config = _PyPathConfig_INIT;
path_config.module_search_path = _PyWstrList_Join(&core_config->module_search_paths, DELIM);
if (path_config.module_search_path == NULL) {
goto no_memory;
}
if (copy_wstr(&path_config.program_full_path, core_config->executable) < 0) {
goto no_memory;
}
if (copy_wstr(&path_config.prefix, core_config->prefix) < 0) {
goto no_memory;
}
if (copy_wstr(&path_config.exec_prefix, core_config->exec_prefix) < 0) {
goto no_memory;
}
#ifdef MS_WINDOWS
if (copy_wstr(&path_config.dll_path, core_config->dll_path) < 0) {
goto no_memory;
}
#endif
if (copy_wstr(&path_config.program_name, core_config->program_name) < 0) {
goto no_memory;
}
if (copy_wstr(&path_config.home, core_config->home) < 0) {
goto no_memory;
}
err = _PyPathConfig_SetGlobal(&path_config);
if (_Py_INIT_FAILED(err)) {
goto done;
}
err = _Py_INIT_OK();
goto done;
no_memory:
err = _Py_INIT_NO_MEMORY();
done:
_PyPathConfig_Clear(&path_config);
PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
return err;
}
static _PyInitError
core_config_init_module_search_paths(_PyCoreConfig *config,
_PyPathConfig *path_config)
{
assert(!config->use_module_search_paths);
_PyWstrList_Clear(&config->module_search_paths);
const wchar_t *sys_path = path_config->module_search_path;
const wchar_t delim = DELIM;
const wchar_t *p = sys_path;
while (1) {
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 _Py_INIT_NO_MEMORY();
}
memcpy(path, sys_path, path_len * sizeof(wchar_t));
path[path_len] = L'\0';
int res = _PyWstrList_Append(&config->module_search_paths, path);
PyMem_RawFree(path);
if (res < 0) {
return _Py_INIT_NO_MEMORY();
}
if (*p == '\0') {
break;
}
sys_path = p + 1;
}
config->use_module_search_paths = 1;
return _Py_INIT_OK();
}
static _PyInitError
_PyCoreConfig_CalculatePathConfig(_PyCoreConfig *config)
{
_PyPathConfig path_config = _PyPathConfig_INIT;
_PyInitError err;
err = _PyPathConfig_Calculate(&path_config, config);
if (_Py_INIT_FAILED(err)) {
goto error;
}
if (!config->use_module_search_paths) {
err = core_config_init_module_search_paths(config, &path_config);
if (_Py_INIT_FAILED(err)) {
goto error;
}
}
if (config->executable == NULL) {
if (copy_wstr(&config->executable,
path_config.program_full_path) < 0) {
goto no_memory;
}
}
if (config->prefix == NULL) {
if (copy_wstr(&config->prefix, path_config.prefix) < 0) {
goto no_memory;
}
}
if (config->exec_prefix == NULL) {
if (copy_wstr(&config->exec_prefix,
path_config.exec_prefix) < 0) {
goto no_memory;
}
}
#ifdef MS_WINDOWS
if (config->dll_path == NULL) {
if (copy_wstr(&config->dll_path, path_config.dll_path) < 0) {
goto no_memory;
}
}
#endif
if (path_config.isolated != -1) {
config->preconfig.isolated = path_config.isolated;
}
if (path_config.site_import != -1) {
config->site_import = path_config.site_import;
}
_PyPathConfig_Clear(&path_config);
return _Py_INIT_OK();
no_memory:
err = _Py_INIT_NO_MEMORY();
error:
_PyPathConfig_Clear(&path_config);
return err;
}
_PyInitError
_PyCoreConfig_InitPathConfig(_PyCoreConfig *config)
{
/* Do we need to calculate the path? */
if (!config->use_module_search_paths
|| (config->executable == NULL)
|| (config->prefix == NULL)
#ifdef MS_WINDOWS
|| (config->dll_path == NULL)
#endif
|| (config->exec_prefix == NULL))
{
_PyInitError err = _PyCoreConfig_CalculatePathConfig(config);
if (_Py_INIT_FAILED(err)) {
return err;
}
}
if (config->base_prefix == NULL) {
if (copy_wstr(&config->base_prefix, config->prefix) < 0) {
return _Py_INIT_NO_MEMORY();
}
}
if (config->base_exec_prefix == NULL) {
if (copy_wstr(&config->base_exec_prefix,
config->exec_prefix) < 0) {
return _Py_INIT_NO_MEMORY();
}
}
return _Py_INIT_OK();
}
static void
pathconfig_global_init(void)
{
if (_Py_path_config.module_search_path != NULL) {
/* Already initialized */
return;
}
_PyInitError err;
_PyCoreConfig config = _PyCoreConfig_INIT;
err = _PyCoreConfig_Read(&config, NULL);
if (_Py_INIT_FAILED(err)) {
goto error;
}
err = _PyCoreConfig_SetPathConfig(&config);
if (_Py_INIT_FAILED(err)) {
goto error;
}
_PyCoreConfig_Clear(&config);
return;
error:
_PyCoreConfig_Clear(&config);
_Py_ExitInitError(err);
}
/* External interface */
void
Py_SetPath(const wchar_t *path)
{
if (path == NULL) {
_PyPathConfig_Clear(&_Py_path_config);
return;
}
PyMemAllocatorEx old_alloc;
_PyMem_SetDefaultAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
_PyPathConfig new_config;
new_config.program_full_path = _PyMem_RawWcsdup(Py_GetProgramName());
int alloc_error = (new_config.program_full_path == NULL);
new_config.prefix = _PyMem_RawWcsdup(L"");
alloc_error |= (new_config.prefix == NULL);
new_config.exec_prefix = _PyMem_RawWcsdup(L"");
alloc_error |= (new_config.exec_prefix == NULL);
#ifdef MS_WINDOWS
new_config.dll_path = _PyMem_RawWcsdup(L"");
alloc_error |= (new_config.dll_path == NULL);
#endif
new_config.module_search_path = _PyMem_RawWcsdup(path);
alloc_error |= (new_config.module_search_path == NULL);
/* steal the home and program_name values (to leave them unchanged) */
new_config.home = _Py_path_config.home;
_Py_path_config.home = NULL;
new_config.program_name = _Py_path_config.program_name;
_Py_path_config.program_name = NULL;
_PyPathConfig_Clear(&_Py_path_config);
_Py_path_config = new_config;
PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
if (alloc_error) {
Py_FatalError("Py_SetPath() failed: out of memory");
}
}
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);
PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
if (_Py_path_config.home == NULL) {
Py_FatalError("Py_SetPythonHome() failed: out of memory");
}
}
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) {
Py_FatalError("Py_SetProgramName() failed: out of memory");
}
}
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) {
Py_FatalError("_Py_SetProgramFullPath() failed: out of memory");
}
}
wchar_t *
Py_GetPath(void)
{
pathconfig_global_init();
return _Py_path_config.module_search_path;
}
wchar_t *
Py_GetPrefix(void)
{
pathconfig_global_init();
return _Py_path_config.prefix;
}
wchar_t *
Py_GetExecPrefix(void)
{
pathconfig_global_init();
return _Py_path_config.exec_prefix;
}
wchar_t *
Py_GetProgramFullPath(void)
{
pathconfig_global_init();
return _Py_path_config.program_full_path;
}
wchar_t*
Py_GetPythonHome(void)
{
pathconfig_global_init();
return _Py_path_config.home;
}
wchar_t *
Py_GetProgramName(void)
{
pathconfig_global_init();
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, but *path0_p can be NULL
if the Unicode object fail to be created.
Return 0 if it fails to resolve the full path (and *path0_p will be NULL).
For example, return 0 if the current working directory has been removed
(bpo-36236) or if argv is empty.
*/
int
_PyPathConfig_ComputeSysPath0(const _PyWstrList *argv, PyObject **path0_p)
{
assert(_PyWstrList_CheckConsistency(argv));
assert(*path0_p == NULL);
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;
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 */
wchar_t path0copy[2 * MAXPATHLEN + 1];
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 */
*path0_p = PyUnicode_FromWideChar(path0, n);
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 the provided buffer. */
int
_Py_FindEnvConfigValue(FILE *env_file, const wchar_t *key,
wchar_t *value, size_t value_size)
{
int result = 0; /* meaning not found */
char buffer[MAXPATHLEN * 2 + 1]; /* allow extra for key, '=', etc. */
buffer[Py_ARRAY_LENGTH(buffer)-1] = '\0';
fseek(env_file, 0, SEEK_SET);
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) {
wcsncpy(value, tok, value_size - 1);
value[value_size - 1] = L'\0';
result = 1;
PyMem_RawFree(tmpbuffer);
break;
}
}
}
PyMem_RawFree(tmpbuffer);
}
}
return result;
}
#ifdef __cplusplus
}
#endif