[3.7] bpo-34977: Use venv redirector instead of original python.exe on Windows (GH-11029)
diff --git a/PC/getpathp.c b/PC/getpathp.c
index 599b41b..1b553d5 100644
--- a/PC/getpathp.c
+++ b/PC/getpathp.c
@@ -536,10 +536,16 @@
get_program_full_path(const _PyCoreConfig *core_config,
PyCalculatePath *calculate, _PyPathConfig *config)
{
+ const wchar_t *pyvenv_launcher;
wchar_t program_full_path[MAXPATHLEN+1];
memset(program_full_path, 0, sizeof(program_full_path));
- if (!GetModuleFileNameW(NULL, program_full_path, MAXPATHLEN)) {
+ /* The launcher may need to force the executable path to a
+ * different environment, so override it here. */
+ pyvenv_launcher = _wgetenv(L"__PYVENV_LAUNCHER__");
+ if (pyvenv_launcher && pyvenv_launcher[0]) {
+ wcscpy_s(program_full_path, MAXPATHLEN+1, pyvenv_launcher);
+ } else if (!GetModuleFileNameW(NULL, program_full_path, MAXPATHLEN)) {
/* GetModuleFileName should never fail when passed NULL */
return _Py_INIT_ERR("Cannot determine program path");
}
diff --git a/PC/launcher.c b/PC/launcher.c
index 7d666aa..f3a7ddc 100644
--- a/PC/launcher.c
+++ b/PC/launcher.c
@@ -28,7 +28,7 @@
#define RC_NO_PYTHON 103
#define RC_NO_MEMORY 104
/*
- * SCRIPT_WRAPPER is used to choose between two variants of an executable built
+ * SCRIPT_WRAPPER is used to choose one of the variants of an executable built
* from this source file. If not defined, the PEP 397 Python launcher is built;
* if defined, a script launcher of the type used by setuptools is built, which
* looks for a script name related to the executable name and runs that script
@@ -40,6 +40,15 @@
#if defined(SCRIPT_WRAPPER)
#define RC_NO_SCRIPT 105
#endif
+/*
+ * VENV_REDIRECT is used to choose the variant that looks for an adjacent or
+ * one-level-higher pyvenv.cfg, and uses its "home" property to locate and
+ * launch the original python.exe.
+ */
+#if defined(VENV_REDIRECT)
+#define RC_NO_VENV_CFG 106
+#define RC_BAD_VENV_CFG 107
+#endif
/* Just for now - static definition */
@@ -97,7 +106,7 @@
#if !defined(_WINDOWS)
fwprintf(stderr, L"%ls\n", message);
#else
- MessageBox(NULL, message, TEXT("Python Launcher is sorry to say ..."),
+ MessageBoxW(NULL, message, L"Python Launcher is sorry to say ...",
MB_OK);
#endif
exit(rc);
@@ -131,6 +140,17 @@
return buf;
}
+#if defined(_DEBUG)
+#if defined(_WINDOWS)
+
+#define PYTHON_EXECUTABLE L"pythonw_d.exe"
+
+#else
+
+#define PYTHON_EXECUTABLE L"python_d.exe"
+
+#endif
+#else
#if defined(_WINDOWS)
#define PYTHON_EXECUTABLE L"pythonw.exe"
@@ -140,6 +160,7 @@
#define PYTHON_EXECUTABLE L"python.exe"
#endif
+#endif
#define MAX_VERSION_SIZE 4
@@ -1456,6 +1477,87 @@
return FALSE; /* If this has been called we cannot continue */
}
+#if defined(VENV_REDIRECT)
+
+static int
+find_home_value(const char *buffer, const char **start, DWORD *length)
+{
+ for (const char *s = strstr(buffer, "home"); s; s = strstr(s + 1, "\nhome")) {
+ if (*s == '\n') {
+ ++s;
+ }
+ for (int i = 4; i > 0 && *s; --i, ++s);
+
+ while (*s && iswspace(*s)) {
+ ++s;
+ }
+ if (*s != L'=') {
+ continue;
+ }
+
+ do {
+ ++s;
+ } while (*s && iswspace(*s));
+
+ *start = s;
+ char *nl = strchr(s, '\n');
+ if (nl) {
+ *length = (DWORD)((ptrdiff_t)nl - (ptrdiff_t)s);
+ } else {
+ *length = (DWORD)strlen(s);
+ }
+ return 1;
+ }
+ return 0;
+}
+#endif
+
+static wchar_t *
+wcsdup_pad(const wchar_t *s, int padding, int *newlen)
+{
+ size_t len = wcslen(s);
+ len += 1 + padding;
+ wchar_t *r = (wchar_t *)malloc(len * sizeof(wchar_t));
+ if (!r) {
+ return NULL;
+ }
+ if (wcscpy_s(r, len, s)) {
+ free(r);
+ return NULL;
+ }
+ *newlen = len < MAXINT ? (int)len : MAXINT;
+ return r;
+}
+
+static wchar_t *
+get_process_name()
+{
+ DWORD bufferLen = MAX_PATH;
+ DWORD len = bufferLen;
+ wchar_t *r = NULL;
+
+ while (!r) {
+ r = (wchar_t *)malloc(bufferLen * sizeof(wchar_t));
+ if (!r) {
+ error(RC_NO_MEMORY, L"out of memory");
+ return NULL;
+ }
+ len = GetModuleFileNameW(NULL, r, bufferLen);
+ if (len == 0) {
+ free(r);
+ error(0, L"Failed to get module name");
+ return NULL;
+ } else if (len == bufferLen &&
+ GetLastError() == ERROR_INSUFFICIENT_BUFFER) {
+ free(r);
+ r = NULL;
+ bufferLen *= 2;
+ }
+ }
+
+ return r;
+}
+
static int
process(int argc, wchar_t ** argv)
{
@@ -1463,21 +1565,27 @@
wchar_t * command;
wchar_t * executable;
wchar_t * p;
+ wchar_t * argv0;
int rc = 0;
- size_t plen;
INSTALLED_PYTHON * ip;
BOOL valid;
DWORD size, attrs;
- HRESULT hr;
wchar_t message[MSGSIZE];
void * version_data;
VS_FIXEDFILEINFO * file_info;
UINT block_size;
- int index;
-#if defined(SCRIPT_WRAPPER)
+#if defined(VENV_REDIRECT)
+ wchar_t * venv_cfg_path;
int newlen;
+#elif defined(SCRIPT_WRAPPER)
wchar_t * newcommand;
wchar_t * av[2];
+ int newlen;
+ HRESULT hr;
+ int index;
+#else
+ HRESULT hr;
+ int index;
#endif
setvbuf(stderr, (char *)NULL, _IONBF, 0);
@@ -1495,6 +1603,7 @@
#else
debug(L"launcher executable: Console\n");
#endif
+#if !defined(VENV_REDIRECT)
/* Get the local appdata folder (non-roaming) */
hr = SHGetFolderPathW(NULL, CSIDL_LOCAL_APPDATA,
NULL, 0, appdata_ini_path);
@@ -1503,9 +1612,7 @@
appdata_ini_path[0] = L'\0';
}
else {
- plen = wcslen(appdata_ini_path);
- p = &appdata_ini_path[plen];
- wcsncpy_s(p, MAX_PATH - plen, L"\\py.ini", _TRUNCATE);
+ wcsncat_s(appdata_ini_path, MAX_PATH, L"\\py.ini", _TRUNCATE);
attrs = GetFileAttributesW(appdata_ini_path);
if (attrs == INVALID_FILE_ATTRIBUTES) {
debug(L"File '%ls' non-existent\n", appdata_ini_path);
@@ -1514,8 +1621,9 @@
debug(L"Using local configuration file '%ls'\n", appdata_ini_path);
}
}
- plen = GetModuleFileNameW(NULL, launcher_ini_path, MAX_PATH);
- size = GetFileVersionInfoSizeW(launcher_ini_path, &size);
+#endif
+ argv0 = get_process_name();
+ size = GetFileVersionInfoSizeW(argv0, &size);
if (size == 0) {
winerror(GetLastError(), message, MSGSIZE);
debug(L"GetFileVersionInfoSize failed: %ls\n", message);
@@ -1523,7 +1631,7 @@
else {
version_data = malloc(size);
if (version_data) {
- valid = GetFileVersionInfoW(launcher_ini_path, 0, size,
+ valid = GetFileVersionInfoW(argv0, 0, size,
version_data);
if (!valid)
debug(L"GetFileVersionInfo failed: %X\n", GetLastError());
@@ -1540,15 +1648,51 @@
free(version_data);
}
}
+
+#if defined(VENV_REDIRECT)
+ /* Allocate some extra space for new filenames */
+ venv_cfg_path = wcsdup_pad(argv0, 32, &newlen);
+ if (!venv_cfg_path) {
+ error(RC_NO_MEMORY, L"Failed to copy module name");
+ }
+ p = wcsrchr(venv_cfg_path, L'\\');
+
+ if (p == NULL) {
+ error(RC_NO_VENV_CFG, L"No pyvenv.cfg file");
+ }
+ p[0] = L'\0';
+ wcscat_s(venv_cfg_path, newlen, L"\\pyvenv.cfg");
+ attrs = GetFileAttributesW(venv_cfg_path);
+ if (attrs == INVALID_FILE_ATTRIBUTES) {
+ debug(L"File '%ls' non-existent\n", venv_cfg_path);
+ p[0] = '\0';
+ p = wcsrchr(venv_cfg_path, L'\\');
+ if (p != NULL) {
+ p[0] = '\0';
+ wcscat_s(venv_cfg_path, newlen, L"\\pyvenv.cfg");
+ attrs = GetFileAttributesW(venv_cfg_path);
+ if (attrs == INVALID_FILE_ATTRIBUTES) {
+ debug(L"File '%ls' non-existent\n", venv_cfg_path);
+ error(RC_NO_VENV_CFG, L"No pyvenv.cfg file");
+ }
+ }
+ }
+ debug(L"Using venv configuration file '%ls'\n", venv_cfg_path);
+#else
+ /* Allocate some extra space for new filenames */
+ if (wcscpy_s(launcher_ini_path, MAX_PATH, argv0)) {
+ error(RC_NO_MEMORY, L"Failed to copy module name");
+ }
p = wcsrchr(launcher_ini_path, L'\\');
+
if (p == NULL) {
debug(L"GetModuleFileNameW returned value has no backslash: %ls\n",
launcher_ini_path);
launcher_ini_path[0] = L'\0';
}
else {
- wcsncpy_s(p, MAX_PATH - (p - launcher_ini_path), L"\\py.ini",
- _TRUNCATE);
+ p[0] = L'\0';
+ wcscat_s(launcher_ini_path, MAX_PATH, L"\\py.ini");
attrs = GetFileAttributesW(launcher_ini_path);
if (attrs == INVALID_FILE_ATTRIBUTES) {
debug(L"File '%ls' non-existent\n", launcher_ini_path);
@@ -1557,6 +1701,7 @@
debug(L"Using global configuration file '%ls'\n", launcher_ini_path);
}
}
+#endif
command = skip_me(GetCommandLineW());
debug(L"Called with command line: %ls\n", command);
@@ -1592,6 +1737,55 @@
command = newcommand;
valid = FALSE;
}
+#elif defined(VENV_REDIRECT)
+ {
+ FILE *f;
+ char buffer[4096]; /* 4KB should be enough for anybody */
+ char *start;
+ DWORD len, cch, cch_actual;
+ size_t cb;
+ if (_wfopen_s(&f, venv_cfg_path, L"r")) {
+ error(RC_BAD_VENV_CFG, L"Cannot read '%ls'", venv_cfg_path);
+ }
+ cb = fread_s(buffer, sizeof(buffer), sizeof(buffer[0]),
+ sizeof(buffer) / sizeof(buffer[0]), f);
+ fclose(f);
+
+ if (!find_home_value(buffer, &start, &len)) {
+ error(RC_BAD_VENV_CFG, L"Cannot find home in '%ls'",
+ venv_cfg_path);
+ }
+
+ cch = MultiByteToWideChar(CP_UTF8, 0, start, len, NULL, 0);
+ if (!cch) {
+ error(0, L"Cannot determine memory for home path");
+ }
+ cch += (DWORD)wcslen(PYTHON_EXECUTABLE) + 1 + 1; /* include sep and null */
+ executable = (wchar_t *)malloc(cch * sizeof(wchar_t));
+ if (executable == NULL) {
+ error(RC_NO_MEMORY, L"A memory allocation failed");
+ }
+ cch_actual = MultiByteToWideChar(CP_UTF8, 0, start, len, executable, cch);
+ if (!cch_actual) {
+ error(RC_BAD_VENV_CFG, L"Cannot decode home path in '%ls'",
+ venv_cfg_path);
+ }
+ if (executable[cch_actual - 1] != L'\\') {
+ executable[cch_actual++] = L'\\';
+ executable[cch_actual] = L'\0';
+ }
+ if (wcscat_s(executable, cch, PYTHON_EXECUTABLE)) {
+ error(RC_BAD_VENV_CFG, L"Cannot create executable path from '%ls'",
+ venv_cfg_path);
+ }
+ if (GetFileAttributesW(executable) == INVALID_FILE_ATTRIBUTES) {
+ error(RC_NO_PYTHON, L"No Python at '%ls'", executable);
+ }
+ if (!SetEnvironmentVariableW(L"__PYVENV_LAUNCHER__", argv0)) {
+ error(0, L"Failed to set launcher environment");
+ }
+ valid = 1;
+ }
#else
if (argc <= 1) {
valid = FALSE;
@@ -1599,7 +1793,6 @@
}
else {
p = argv[1];
- plen = wcslen(p);
if ((argc == 2) && // list version args
(!wcsncmp(p, L"-0", wcslen(L"-0")) ||
!wcsncmp(p, L"--list", wcslen(L"--list"))))