Issue #28137: Renames Windows path file to ._pth

Issue #28138: Windows ._pth file should allow import site
This commit is contained in:
Steve Dower 2016-09-17 12:54:06 -07:00
parent 313523ce2d
commit ed51b26858
5 changed files with 119 additions and 52 deletions

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@ -720,15 +720,24 @@ installation directory. So, if you had installed Python to
:file:`C:\\Python\\Lib\\` and third-party modules should be stored in
:file:`C:\\Python\\Lib\\site-packages\\`.
To completely override :data:`sys.path`, create a text file named ``'sys.path'``
containing a list of paths alongside the Python executable. This will ignore all
registry settings and environment variables, enable isolated mode, disable
importing :mod:`site`, and fill :data:`sys.path` with exactly the paths listed
in the file. Paths may be absolute or relative to the directory containing the
file.
To completely override :data:`sys.path`, create a ``._pth`` file with the same
name as the DLL (``python36._pth``) or the executable (``python._pth``) and
specify one line for each path to add to :data:`sys.path`. The file based on the
DLL name overrides the one based on the executable, which allows paths to be
restricted for any program loading the runtime if desired.
When the ``'sys.path'`` file is missing, this is how :data:`sys.path` is
populated on Windows:
When the file exists, all registry and environment variables are ignored,
isolated mode is enabled, and :mod:`site` is not imported unless one line in the
file specifies ``import site``. Blank paths and lines starting with ``#`` are
ignored. Each path may be absolute or relative to the location of the file.
Import statements other than to ``site`` are not permitted, and arbitrary code
cannot be specified.
Note that ``.pth`` files (without leading underscore) will be processed normally
by the :mod:`site` module.
When no ``._pth`` file is found, this is how :data:`sys.path` is populated on
Windows:
* An empty entry is added at the start, which corresponds to the current
directory.
@ -782,9 +791,10 @@ The end result of all this is:
For those who want to bundle Python into their application or distribution, the
following advice will prevent conflicts with other installations:
* Include a ``sys.path`` file alongside your executable containing the
directories to include. This will ignore user site-packages and other paths
listed in the registry or in environment variables.
* Include a ``._pth`` file alongside your executable containing the
directories to include. This will ignore paths listed in the registry and
environment variables, and also ignore :mod:`site` unless ``import site`` is
listed.
* If you are loading :file:`python3.dll` or :file:`python36.dll` in your own
executable, explicitly call :c:func:`Py_SetPath` or (at least)

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@ -108,7 +108,7 @@ Windows improvements:
which means that when the 260 character path limit may no longer apply.
See :ref:`removing the MAX_PATH limitation <max-path>` for details.
* A ``sys.path`` file can be added to force isolated mode and fully specify
* A ``._pth`` file can be added to force isolated mode and fully specify
all search paths to avoid registry and environment lookup. See
:ref:`the documentation <finding_modules>` for more information.

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@ -10,6 +10,8 @@ What's New in Python 3.6.0 beta 2
Core and Builtins
-----------------
- Issue #28192: Don't import readline in isolated mode.
- Upgrade internal unicode databases to Unicode version 9.0.0.
- Issue #28131: Fix a regression in zipimport's compile_source(). zipimport
@ -64,6 +66,13 @@ Library
- Issue #27759: Fix selectors incorrectly retain invalid file descriptors.
Patch by Mark Williams.
Windows
-------
- Issue #28137: Renames Windows path file to ._pth
- Issue #28138: Windows ._pth file should allow import site
Build
-----

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@ -6,8 +6,9 @@
PATH RULES FOR WINDOWS:
This describes how sys.path is formed on Windows. It describes the
functionality, not the implementation (ie, the order in which these
are actually fetched is different). The presence of a sys.path file
alongside the program overrides these rules - see below.
are actually fetched is different). The presence of a python._pth or
pythonXY._pth file alongside the program overrides these rules - see
below.
* Python always adds an empty entry at the start, which corresponds
to the current directory.
@ -37,11 +38,21 @@
used (eg. .\Lib;.\DLLs, etc)
If a sys.path file exists adjacent to python.exe, it must contain a
list of paths to add to sys.path, one per line (like a .pth file but without
the ability to execute arbitrary code). Each path is relative to the
directory containing the file. No other paths are added to the search path,
and the registry finder is not enabled.
If a '._pth' file exists adjacent to the executable with the same base name
(e.g. python._pth adjacent to python.exe) or adjacent to the shared library
(e.g. python36._pth adjacent to python36.dll), it is used in preference to
the above process. The shared library file takes precedence over the
executable. The path file must contain a list of paths to add to sys.path,
one per line. Each path is relative to the directory containing the file.
Blank lines and comments beginning with '#' are permitted.
In the presence of this ._pth file, no other paths are added to the search
path, the registry finder is not enabled, site.py is not imported and
isolated mode is enabled. The site package can be enabled by including a
line reading "import site"; no other imports are recognized. Any invalid
entry (other than directories that do not exist) will result in immediate
termination of the program.
The end result of all this is:
* When running python.exe, or any other .exe in the main Python directory
@ -61,8 +72,9 @@
* An embedding application can use Py_SetPath() to override all of
these automatic path computations.
* An isolation install of Python can disable all implicit paths by
providing a sys.path file.
* An install of Python can fully specify the contents of sys.path using
either a 'EXENAME._pth' or 'DLLNAME._pth' file, optionally including
"import site" to enable the site module.
---------------------------------------------------------------- */
@ -135,6 +147,33 @@ reduce(wchar_t *dir)
dir[i] = '\0';
}
static int
change_ext(wchar_t *dest, const wchar_t *src, const wchar_t *ext)
{
size_t src_len = wcsnlen_s(src, MAXPATHLEN+1);
size_t i = src_len;
if (i >= MAXPATHLEN+1)
Py_FatalError("buffer overflow in getpathp.c's reduce()");
while (i > 0 && src[i] != '.' && !is_sep(src[i]))
--i;
if (i == 0) {
dest[0] = '\0';
return -1;
}
if (is_sep(src[i]))
i = src_len;
if (wcsncpy_s(dest, MAXPATHLEN+1, src, i) ||
wcscat_s(dest, MAXPATHLEN+1, ext)) {
dest[0] = '\0';
return -1;
}
return 0;
}
static int
exists(wchar_t *filename)
@ -499,12 +538,17 @@ find_env_config_value(FILE * env_file, const wchar_t * key, wchar_t * value)
}
static int
read_sys_path_file(const wchar_t *path, const wchar_t *prefix)
read_pth_file(const wchar_t *path, wchar_t *prefix, int *isolated, int *nosite)
{
FILE *sp_file = _Py_wfopen(path, L"r");
if (sp_file == NULL)
return -1;
wcscpy_s(prefix, MAXPATHLEN+1, path);
reduce(prefix);
*isolated = 1;
*nosite = 1;
size_t bufsiz = MAXPATHLEN;
size_t prefixlen = wcslen(prefix);
@ -516,16 +560,25 @@ read_sys_path_file(const wchar_t *path, const wchar_t *prefix)
char *p = fgets(line, MAXPATHLEN + 1, sp_file);
if (!p)
break;
if (*p == '\0' || *p == '#')
continue;
while (*++p) {
if (*p == '\r' || *p == '\n') {
*p = '\0';
break;
}
}
DWORD n = strlen(line);
if (n == 0 || p[n - 1] != '\n')
break;
if (n > 2 && p[n - 1] == '\r')
--n;
if (strcmp(line, "import site") == 0) {
*nosite = 0;
continue;
} else if (strncmp(line, "import ", 7) == 0) {
Py_FatalError("only 'import site' is supported in ._pth file");
}
DWORD wn = MultiByteToWideChar(CP_UTF8, 0, line, n - 1, NULL, 0);
DWORD wn = MultiByteToWideChar(CP_UTF8, 0, line, -1, NULL, 0);
wchar_t *wline = (wchar_t*)PyMem_RawMalloc((wn + 1) * sizeof(wchar_t));
wn = MultiByteToWideChar(CP_UTF8, 0, line, n - 1, wline, wn);
wn = MultiByteToWideChar(CP_UTF8, 0, line, -1, wline, wn + 1);
wline[wn] = '\0';
while (wn + prefixlen + 4 > bufsiz) {
@ -539,8 +592,8 @@ read_sys_path_file(const wchar_t *path, const wchar_t *prefix)
if (buf[0])
wcscat_s(buf, bufsiz, L";");
wchar_t *b = &buf[wcslen(buf)];
wcscat_s(buf, bufsiz, prefix);
join(b, wline);
@ -586,13 +639,12 @@ calculate_path(void)
{
wchar_t spbuffer[MAXPATHLEN+1];
wcscpy_s(spbuffer, MAXPATHLEN+1, argv0_path);
join(spbuffer, L"sys.path");
if (exists(spbuffer) && read_sys_path_file(spbuffer, argv0_path) == 0) {
wcscpy_s(prefix, MAXPATHLEN + 1, argv0_path);
Py_IsolatedFlag = 1;
Py_NoSiteFlag = 1;
return;
if ((dllpath[0] && !change_ext(spbuffer, dllpath, L"._pth") && exists(spbuffer)) ||
(progpath[0] && !change_ext(spbuffer, progpath, L"._pth") && exists(spbuffer))) {
if (!read_pth_file(spbuffer, prefix, &Py_IsolatedFlag, &Py_NoSiteFlag)) {
return;
}
}
}
@ -631,16 +683,7 @@ calculate_path(void)
}
/* Calculate zip archive path from DLL or exe path */
if (wcscpy_s(zip_path, MAXPATHLEN + 1, dllpath[0] ? dllpath : progpath)) {
/* exceeded buffer length - ignore zip_path */
zip_path[0] = '\0';
} else {
wchar_t *dot = wcsrchr(zip_path, '.');
if (!dot || wcscpy_s(dot, MAXPATHLEN + 1 - (dot - zip_path), L".zip")) {
/* exceeded buffer length - ignore zip_path */
zip_path[0] = L'\0';
}
}
change_ext(zip_path, dllpath[0] ? dllpath : progpath, L".zip");
if (pythonhome == NULL || *pythonhome == '\0') {
if (zip_path[0] && exists(zip_path)) {

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@ -91,11 +91,13 @@ def include_in_tools(p):
return p.suffix.lower() in {'.py', '.pyw', '.txt'}
BASE_NAME = 'python{0.major}{0.minor}'.format(sys.version_info)
FULL_LAYOUT = [
('/', 'PCBuild/$arch', 'python.exe', is_not_debug),
('/', 'PCBuild/$arch', 'pythonw.exe', is_not_debug),
('/', 'PCBuild/$arch', 'python{0.major}.dll'.format(sys.version_info), is_not_debug),
('/', 'PCBuild/$arch', 'python{0.major}{0.minor}.dll'.format(sys.version_info), is_not_debug),
('/', 'PCBuild/$arch', 'python{}.dll'.format(sys.version_info.major), is_not_debug),
('/', 'PCBuild/$arch', '{}.dll'.format(BASE_NAME), is_not_debug),
('DLLs/', 'PCBuild/$arch', '*.pyd', is_not_debug),
('DLLs/', 'PCBuild/$arch', '*.dll', is_not_debug_or_python),
('include/', 'include', '*.h', None),
@ -109,7 +111,7 @@ EMBED_LAYOUT = [
('/', 'PCBuild/$arch', 'python*.exe', is_not_debug),
('/', 'PCBuild/$arch', '*.pyd', is_not_debug),
('/', 'PCBuild/$arch', '*.dll', is_not_debug),
('python{0.major}{0.minor}.zip'.format(sys.version_info), 'Lib', '**/*', include_in_lib),
('{}.zip'.format(BASE_NAME), 'Lib', '**/*', include_in_lib),
]
if os.getenv('DOC_FILENAME'):
@ -209,9 +211,12 @@ def main():
print('Copied {} files'.format(copied))
if ns.embed:
with open(str(temp / 'sys.path'), 'w') as f:
print('python{0.major}{0.minor}.zip'.format(sys.version_info), file=f)
with open(str(temp / (BASE_NAME + '._pth')), 'w') as f:
print(BASE_NAME + '.zip', file=f)
print('.', file=f)
print('', file=f)
print('# Uncomment to run site.main() automatically', file=f)
print('#import site', file=f)
if out:
total = copy_to_layout(out, rglob(temp, '**/*', None))