Issue #23465: Implement PEP 486 - Make the Python Launcher aware of virtual environments (patch by Paul Moore)
diff --git a/PC/launcher.c b/PC/launcher.c
index d450d9f..33dd5da 100644
--- a/PC/launcher.c
+++ b/PC/launcher.c
@@ -384,6 +384,31 @@
}
+static wchar_t *
+find_python_by_venv()
+{
+ static wchar_t venv_python[MAX_PATH];
+ wchar_t *virtual_env = get_env(L"VIRTUAL_ENV");
+ DWORD attrs;
+
+ /* Check for VIRTUAL_ENV environment variable */
+ if (virtual_env == NULL || virtual_env[0] == L'\0') {
+ return NULL;
+ }
+
+ /* Check for a python executable in the venv */
+ debug(L"Checking for Python executable in virtual env '%ls'\n", virtual_env);
+ _snwprintf_s(venv_python, MAX_PATH, _TRUNCATE,
+ L"%ls\\Scripts\\%ls", virtual_env, PYTHON_EXECUTABLE);
+ attrs = GetFileAttributesW(venv_python);
+ if (attrs == INVALID_FILE_ATTRIBUTES) {
+ debug(L"Python executable %ls missing from virtual env\n", venv_python);
+ return NULL;
+ }
+
+ return venv_python;
+}
+
static wchar_t appdata_ini_path[MAX_PATH];
static wchar_t launcher_ini_path[MAX_PATH];
@@ -1309,6 +1334,7 @@
{
wchar_t * wp;
wchar_t * command;
+ wchar_t * executable;
wchar_t * p;
int rc = 0;
size_t plen;
@@ -1453,6 +1479,7 @@
if (ip == NULL)
error(RC_NO_PYTHON, L"Requested Python version (%ls) not \
installed", &p[1]);
+ executable = ip->executable;
command += wcslen(p);
command = skip_whitespace(command);
}
@@ -1470,9 +1497,16 @@
#endif
if (!valid) {
- ip = locate_python(L"");
- if (ip == NULL)
- error(RC_NO_PYTHON, L"Can't find a default Python.");
+ /* Look for an active virtualenv */
+ executable = find_python_by_venv();
+
+ /* If we didn't find one, look for the default Python */
+ if (executable == NULL) {
+ ip = locate_python(L"");
+ if (ip == NULL)
+ error(RC_NO_PYTHON, L"Can't find a default Python.");
+ executable = ip->executable;
+ }
if ((argc == 2) && (!_wcsicmp(p, L"-h") || !_wcsicmp(p, L"--help"))) {
#if defined(_M_X64)
BOOL canDo64bit = TRUE;
@@ -1500,7 +1534,7 @@
fflush(stdout);
}
}
- invoke_child(ip->executable, NULL, command);
+ invoke_child(executable, NULL, command);
return rc;
}