Issue #28137: Renames Windows path file to ._pth
Issue #28138: Windows ._pth file should allow import site
diff --git a/PC/getpathp.c b/PC/getpathp.c
index c05754a..31f973e 100644
--- a/PC/getpathp.c
+++ b/PC/getpathp.c
@@ -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 @@
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 @@
}
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 @@
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 @@
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 @@
{
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 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)) {