bpo-32197: Try to fix a compiler error on OS X introduced in bpo-32030. (#4681)

* Revert "bpo-32030: _PyPathConfig_Init() sets home and program_name (#4673)"

This reverts commit af5a895073c24637c094772b27526b94a12ec897.

* Revert "bpo-32030: Fix config_get_program_name() on macOS (#4669)"

This reverts commit e23c06e2b03452c9aaf0dae52296c85e572f9bcd.

* Revert "bpo-32030: Add Python/pathconfig.c (#4668)"

This reverts commit 0ea395ae964c9cd0f499e2ef0d0030c971201220.

* Revert "bpo-32030: Don't call _PyPathConfig_Fini() in Py_FinalizeEx() (#4667)"

This reverts commit ebac19dad6263141d5db0a2c923efe049dba99d2.

* Revert "bpo-32030: Fix Py_GetPath(): init program_name (#4665)"

This reverts commit 9ac3d8882712c9675c3d2f9f84af6b5729575cde.

1 files changed, 58 insertions, 6 deletions

diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
index 523397f126..f0a49f91fb 100644
--- a/Python/pylifecycle.c
+++ b/Python/pylifecycle.c
@@ -804,12 +804,7 @@ _PyMainInterpreterConfig_Read(_PyMainInterpreterConfig *config)
     }
 
     if (config->program_name == NULL) {
-#ifdef MS_WINDOWS
-        const wchar_t *program_name = L"python";
-#else
-        const wchar_t *program_name = L"python3";
-#endif
-        config->program_name = _PyMem_RawWcsdup(program_name);
+        config->program_name = _PyMem_RawWcsdup(Py_GetProgramName());
         if (config->program_name == NULL) {
             return _Py_INIT_NO_MEMORY();
         }
@@ -1278,6 +1273,8 @@ Py_FinalizeEx(void)
 
     call_ll_exitfuncs();
 
+    _PyPathConfig_Fini();
+
     _PyRuntime_Finalize();
     return status;
 }
@@ -1494,6 +1491,61 @@ Py_EndInterpreter(PyThreadState *tstate)
     PyInterpreterState_Delete(interp);
 }
 
+#ifdef MS_WINDOWS
+static wchar_t *progname = L"python";
+#else
+static wchar_t *progname = L"python3";
+#endif
+
+void
+Py_SetProgramName(wchar_t *pn)
+{
+    if (pn && *pn)
+        progname = pn;
+}
+
+wchar_t *
+Py_GetProgramName(void)
+{
+    return progname;
+}
+
+static wchar_t *default_home = NULL;
+
+void
+Py_SetPythonHome(wchar_t *home)
+{
+    default_home = home;
+}
+
+
+wchar_t*
+Py_GetPythonHome(void)
+{
+    /* Use a static buffer to avoid heap memory allocation failure.
+       Py_GetPythonHome() doesn't allow to report error, and the caller
+       doesn't release memory. */
+    static wchar_t buffer[MAXPATHLEN+1];
+
+    if (default_home) {
+        return default_home;
+    }
+
+    char *home = Py_GETENV("PYTHONHOME");
+    if (!home) {
+        return NULL;
+    }
+
+    size_t size = Py_ARRAY_LENGTH(buffer);
+    size_t r = mbstowcs(buffer, home, size);
+    if (r == (size_t)-1 || r >= size) {
+        /* conversion failed or the static buffer is too small */
+        return NULL;
+    }
+
+    return buffer;
+}
+
 /* Add the __main__ module */
 
 static _PyInitError