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 af5a8950.

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

This reverts commit e23c06e2.

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

This reverts commit 0ea395ae.

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

This reverts commit ebac19da.

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

This reverts commit 9ac3d888.

Doc/c-api/init.rst

@@ -40,6 +40,7 @@ The following functions can be safely called before Python is initialized:
   * :c:func:`Py_GetCompiler`
   * :c:func:`Py_GetCopyright`
   * :c:func:`Py_GetPlatform`
+  * :c:func:`Py_GetProgramName`
   * :c:func:`Py_GetVersion`
 
 * Utilities:
@@ -58,8 +59,8 @@ The following functions can be safely called before Python is initialized:
    The following functions **should not be called** before
    :c:func:`Py_Initialize`: :c:func:`Py_EncodeLocale`, :c:func:`Py_GetPath`,
    :c:func:`Py_GetPrefix`, :c:func:`Py_GetExecPrefix`,
-   :c:func:`Py_GetProgramFullPath`, :c:func:`Py_GetPythonHome`,
-   :c:func:`Py_GetProgramName` and :c:func:`PyEval_InitThreads`.
+   :c:func:`Py_GetProgramFullPath`, :c:func:`Py_GetPythonHome` and
+   :c:func:`PyEval_InitThreads`.
 
 
 .. _global-conf-vars:

Include/internal/pystate.h

@@ -48,36 +48,9 @@ typedef struct {
 #endif
     /* Set by Py_SetPath(), or computed by _PyPathConfig_Init() */
     wchar_t *module_search_path;
-    /* Python program name */
-    wchar_t *program_name;
-    /* Set by Py_SetPythonHome() or PYTHONHOME environment variable */
-    wchar_t *home;
 } _PyPathConfig;
 
-#ifdef MS_WINDOWS
-#define _PyPathConfig_INIT \
-    {.program_full_path = NULL, \
-     .prefix = NULL, \
-     .dll_path = NULL, \
-     .module_search_path = NULL, \
-     .program_name = NULL, \
-     .home = NULL}
-#else
-#define _PyPathConfig_INIT \
-    {.program_full_path = NULL, \
-     .prefix = NULL, \
-     .exec_prefix = NULL, \
-     .module_search_path = NULL, \
-     .program_name = NULL, \
-     .home = NULL}
-#endif
-
-PyAPI_DATA(_PyPathConfig) _Py_path_config;
-
-PyAPI_FUNC(_PyInitError) _PyPathConfig_Calculate(
-    _PyPathConfig *config,
-    const _PyMainInterpreterConfig *main_config);
-PyAPI_FUNC(void) _PyPathConfig_Clear(_PyPathConfig *config);
+#define _PyPathConfig_INIT {.module_search_path = NULL}
 
 
 /* Full Python runtime state */

Include/pylifecycle.h

@@ -105,10 +105,11 @@ PyAPI_FUNC(wchar_t *) Py_GetPath(void);
 #ifdef Py_BUILD_CORE
 PyAPI_FUNC(_PyInitError) _PyPathConfig_Init(
     const _PyMainInterpreterConfig *main_config);
+PyAPI_FUNC(void) _PyPathConfig_Fini(void);
 #endif
 PyAPI_FUNC(void)      Py_SetPath(const wchar_t *);
 #ifdef MS_WINDOWS
-int _Py_CheckPython3(void);
+int _Py_CheckPython3();
 #endif
 
 /* In their own files */

Include/pystate.h

@@ -72,8 +72,7 @@ typedef struct {
     (_PyMainInterpreterConfig){\
      .install_signal_handlers = -1, \
      .module_search_path_env = NULL, \
-     .home = NULL, \
-     .program_name = NULL}
+     .home = NULL}
 
 typedef struct _is {
 

Makefile.pre.in

@@ -337,9 +337,8 @@ PYTHON_OBJS=	\
 		Python/importdl.o \
 		Python/marshal.o \
 		Python/modsupport.o \
-		Python/mysnprintf.o \
 		Python/mystrtoul.o \
-		Python/pathconfig.o \
+		Python/mysnprintf.o \
 		Python/peephole.o \
 		Python/pyarena.o \
 		Python/pyctype.o \

Modules/main.c

@@ -412,6 +412,7 @@ typedef struct {
     /* non-zero if filename, command (-c) or module (-m) is set
        on the command line */
     int run_code;
+    wchar_t *program_name;
     /* Error message if a function failed */
     _PyInitError err;
     /* PYTHONWARNINGS env var */
@@ -428,6 +429,7 @@ typedef struct {
      .config = _PyMainInterpreterConfig_INIT, \
      .main_importer_path = NULL, \
      .run_code = -1, \
+     .program_name = NULL, \
      .err = _Py_INIT_OK(), \
      .env_warning_options = {0, NULL}}
 
@@ -453,6 +455,7 @@ pymain_free_impl(_PyMain *pymain)
 
     pymain_optlist_clear(&pymain->env_warning_options);
     Py_CLEAR(pymain->main_importer_path);
+    PyMem_RawFree(pymain->program_name);
 
     _PyMainInterpreterConfig_Clear(&pymain->config);
 
@@ -871,21 +874,14 @@ pymain_init_stdio(_PyMain *pymain)
 
 
 /* Get the program name: use PYTHONEXECUTABLE and __PYVENV_LAUNCHER__
-   environment variables on macOS if available. */
-static _PyInitError
-config_get_program_name(_PyMainInterpreterConfig *config)
-{
-    assert(config->program_name == NULL);
-
-    /* If Py_SetProgramName() was called, use its value */
-    wchar_t *program_name = _Py_path_config.program_name;
-    if (program_name != NULL) {
-        config->program_name = _PyMem_RawWcsdup(program_name);
-        if (config->program_name == NULL) {
-            return _Py_INIT_NO_MEMORY();
-        }
-    }
+   environment variables on macOS if available, use argv[0] by default.
 
+   Return 0 on success.
+   Set pymain->err and return -1 on error. */
+static int
+pymain_get_program_name(_PyMain *pymain)
+{
+    assert(pymain->program_name == NULL);
 #ifdef __APPLE__
     char *p;
     /* On MacOS X, when the Python interpreter is embedded in an
@@ -898,13 +894,17 @@ config_get_program_name(_PyMainInterpreterConfig *config)
        See Lib/plat-mac/bundlebuiler.py for details about the bootstrap
        script. */
     if ((p = Py_GETENV("PYTHONEXECUTABLE")) && *p != '\0') {
-        size_t len;
-        wchar_t* program_name = Py_DecodeLocale(p, &len);
-        if (program_name == NULL) {
-            return SET_DECODE_ERROR("PYTHONEXECUTABLE environment "
-                                    "variable", len);
+        wchar_t* buffer;
+        size_t len = strlen(p) + 1;
+
+        buffer = PyMem_RawMalloc(len * sizeof(wchar_t));
+        if (buffer == NULL) {
+            pymain->err = _Py_INIT_NO_MEMORY();
+            return -1;
         }
-        config->program_name = program_name;
+
+        mbstowcs(buffer, p, len);
+        pymain->program_name = buffer;
     }
 #ifdef WITH_NEXT_FRAMEWORK
     else {
@@ -914,30 +914,21 @@ config_get_program_name(_PyMainInterpreterConfig *config)
              * the argv0 of the stub executable
              */
             size_t len;
-            wchar_t* program_name = Py_DecodeLocale(pyvenv_launcher, &len);
-            if (program_name == NULL) {
-                return SET_DECODE_ERROR("__PYVENV_LAUNCHER__ environment "
-                                        "variable", len);
+            wchar_t* wbuf = Py_DecodeLocale(pyvenv_launcher, &len);
+            if (wbuf == NULL) {
+                SET_DECODE_ERROR("__PYVENV_LAUNCHER__", len);
+                return -1;
             }
-            config->program_name = program_name;
+            pymain->program_name = wbuf;
         }
     }
 #endif   /* WITH_NEXT_FRAMEWORK */
 #endif   /* __APPLE__ */
 
-    return _Py_INIT_OK();
-}
-
-
-/* If config_get_program_name() found no program name: use argv[0] by default.
-   Return 0 on success. Set pymain->err and return -1 on error. */
-static int
-pymain_get_program_name(_PyMain *pymain)
-{
-    if (pymain->config.program_name == NULL) {
+    if (pymain->program_name == NULL) {
         /* Use argv[0] by default */
-        pymain->config.program_name = pymain_wstrdup(pymain, pymain->argv[0]);
-        if (pymain->config.program_name == NULL) {
+        pymain->program_name = pymain_wstrdup(pymain, pymain->argv[0]);
+        if (pymain->program_name == NULL) {
             return -1;
         }
     }
@@ -959,6 +950,13 @@ pymain_init_main_interpreter(_PyMain *pymain)
 {
     _PyInitError err;
 
+    /* TODO: Print any exceptions raised by these operations */
+    err = _PyMainInterpreterConfig_Read(&pymain->config);
+    if (_Py_INIT_FAILED(err)) {
+        pymain->err = err;
+        return -1;
+    }
+
     err = _Py_InitializeMainInterpreter(&pymain->config);
     if (_Py_INIT_FAILED(err)) {
         pymain->err = err;
@@ -1416,13 +1414,14 @@ config_init_pythonpath(_PyMainInterpreterConfig *config)
 
 
 static _PyInitError
-config_init_home(_PyMainInterpreterConfig *config)
+config_init_pythonhome(_PyMainInterpreterConfig *config)
 {
     wchar_t *home;
 
-    /* If Py_SetPythonHome() was called, use its value */
-    home = _Py_path_config.home;
+    home = Py_GetPythonHome();
     if (home) {
+        /* Py_SetPythonHome() has been called before Py_Main(),
+           use its value */
         config->home = _PyMem_RawWcsdup(home);
         if (config->home == NULL) {
             return _Py_INIT_NO_MEMORY();
@@ -1442,7 +1441,7 @@ config_init_home(_PyMainInterpreterConfig *config)
 _PyInitError
 _PyMainInterpreterConfig_ReadEnv(_PyMainInterpreterConfig *config)
 {
-    _PyInitError err = config_init_home(config);
+    _PyInitError err = config_init_pythonhome(config);
     if (_Py_INIT_FAILED(err)) {
         return err;
     }
@@ -1452,9 +1451,11 @@ _PyMainInterpreterConfig_ReadEnv(_PyMainInterpreterConfig *config)
         return err;
     }
 
-    err = config_get_program_name(config);
-    if (_Py_INIT_FAILED(err)) {
-        return err;
+    /* FIXME: _PyMainInterpreterConfig_Read() has the same code. Remove it
+       here? See also pymain_get_program_name() and pymain_parse_envvars(). */
+    config->program_name = _PyMem_RawWcsdup(Py_GetProgramName());
+    if (config->program_name == NULL) {
+        return _Py_INIT_NO_MEMORY();
     }
 
     return _Py_INIT_OK();
@@ -1480,17 +1481,25 @@ pymain_parse_envvars(_PyMain *pymain)
     if (pymain_warnings_envvar(pymain) < 0) {
         return -1;
     }
+    if (pymain_get_program_name(pymain) < 0) {
+        return -1;
+    }
+    core_config->allocator = Py_GETENV("PYTHONMALLOC");
+
+    /* FIXME: move pymain_get_program_name() code into
+       _PyMainInterpreterConfig_ReadEnv().
+       Problem: _PyMainInterpreterConfig_ReadEnv() doesn't have access
+       to argv[0]. */
+    Py_SetProgramName(pymain->program_name);
+    /* Don't free program_name here: the argument to Py_SetProgramName
+       must remain valid until Py_FinalizeEx is called. The string is freed
+       by pymain_free(). */
 
     _PyInitError err = _PyMainInterpreterConfig_ReadEnv(&pymain->config);
     if (_Py_INIT_FAILED(pymain->err)) {
         pymain->err = err;
         return -1;
     }
-    if (pymain_get_program_name(pymain) < 0) {
-        return -1;
-    }
-
-    core_config->allocator = Py_GETENV("PYTHONMALLOC");
 
     /* -X options */
     if (pymain_get_xoption(pymain, L"showrefcount")) {
@@ -1546,12 +1555,6 @@ pymain_parse_cmdline_envvars_impl(_PyMain *pymain)
         return -1;
     }
 
-    _PyInitError err = _PyMainInterpreterConfig_Read(&pymain->config);
-    if (_Py_INIT_FAILED(err)) {
-        pymain->err = err;
-        return -1;
-    }
-
     return 0;
 }
 
@@ -1668,14 +1671,6 @@ pymain_impl(_PyMain *pymain)
            other special meaning */
         pymain->status = 120;
     }
-
-    /* _PyPathConfig_Clear() cannot be called in Py_FinalizeEx().
-       Py_Initialize() and Py_Finalize() can be called multiple times, but it
-       must not "forget" parameters set by Py_SetProgramName(), Py_SetPath() or
-       Py_SetPythonHome(), whereas _PyPathConfig_Clear() clear all these
-       parameters. */
-    _PyPathConfig_Clear(&_Py_path_config);
-
     return 0;
 }
 

PCbuild/pythoncore.vcxproj

@@ -381,7 +381,6 @@
     <ClCompile Include="..\Python\modsupport.c" />
     <ClCompile Include="..\Python\mysnprintf.c" />
     <ClCompile Include="..\Python\mystrtoul.c" />
-    <ClCompile Include="..\Python\pathconfig.c" />
     <ClCompile Include="..\Python\peephole.c" />
     <ClCompile Include="..\Python\pyarena.c" />
     <ClCompile Include="..\Python\pyctype.c" />

PCbuild/pythoncore.vcxproj.filters

@@ -896,9 +896,6 @@
     <ClCompile Include="..\Python\mystrtoul.c">
       <Filter>Python</Filter>
     </ClCompile>
-    <ClCompile Include="..\Python\pathconfig.c">
-      <Filter>Python</Filter>
-    </ClCompile>
     <ClCompile Include="..\Python\peephole.c">
       <Filter>Python</Filter>
     </ClCompile>

Python/pathconfig.c

-/* Path configuration like module_search_path (sys.path) */
-
-#include "Python.h"
-#include "osdefs.h"
-#include "internal/pystate.h"
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-
-_PyPathConfig _Py_path_config = _PyPathConfig_INIT;
-
-
-void
-_PyPathConfig_Clear(_PyPathConfig *config)
-{
-    /* _PyMem_SetDefaultAllocator() is needed to get a known memory allocator,
-       since Py_SetPath(), Py_SetPythonHome() and Py_SetProgramName() can be
-       called before Py_Initialize() which can changes the memory allocator. */
-    PyMemAllocatorEx old_alloc;
-    _PyMem_SetDefaultAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
-
-#define CLEAR(ATTR) \
-    do { \
-        PyMem_RawFree(ATTR); \
-        ATTR = NULL; \
-    } while (0)
-
-    CLEAR(config->prefix);
-    CLEAR(config->program_full_path);
-#ifdef MS_WINDOWS
-    CLEAR(config->dll_path);
-#else
-    CLEAR(config->exec_prefix);
-#endif
-    CLEAR(config->module_search_path);
-    CLEAR(config->home);
-    CLEAR(config->program_name);
-#undef CLEAR
-
-    PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
-}
-
-
-/* Initialize paths for Py_GetPath(), Py_GetPrefix(), Py_GetExecPrefix()
-   and Py_GetProgramFullPath() */
-_PyInitError
-_PyPathConfig_Init(const _PyMainInterpreterConfig *main_config)
-{
-    if (_Py_path_config.module_search_path) {
-        /* Already initialized */
-        return _Py_INIT_OK();
-    }
-
-    _PyInitError err;
-    _PyPathConfig new_config = _PyPathConfig_INIT;
-
-    PyMemAllocatorEx old_alloc;
-    _PyMem_SetDefaultAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
-
-    /* Calculate program_full_path, prefix, exec_prefix (Unix)
-       or dll_path (Windows), and module_search_path */
-    err = _PyPathConfig_Calculate(&new_config, main_config);
-    if (_Py_INIT_FAILED(err)) {
-        _PyPathConfig_Clear(&new_config);
-        goto done;
-    }
-
-    /* Copy home and program_name from main_config */
-    if (main_config->home != NULL) {
-        new_config.home = _PyMem_RawWcsdup(main_config->home);
-        if (new_config.home == NULL) {
-            err = _Py_INIT_NO_MEMORY();
-            goto done;
-        }
-    }
-    else {
-        new_config.home = NULL;
-    }
-
-    new_config.program_name = _PyMem_RawWcsdup(main_config->program_name);
-    if (new_config.program_name == NULL) {
-        err = _Py_INIT_NO_MEMORY();
-        goto done;
-    }
-
-    _PyPathConfig_Clear(&_Py_path_config);
-    _Py_path_config = new_config;
-
-    err = _Py_INIT_OK();
-
-done:
-    PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
-    return err;
-}
-
-
-static void
-pathconfig_global_init(void)
-{
-    if (_Py_path_config.module_search_path) {
-        /* Already initialized */
-        return;
-    }
-
-    _PyInitError err;
-    _PyMainInterpreterConfig config = _PyMainInterpreterConfig_INIT;
-
-    err = _PyMainInterpreterConfig_ReadEnv(&config);
-    if (_Py_INIT_FAILED(err)) {
-        goto error;
-    }
-
-    err = _PyMainInterpreterConfig_Read(&config);
-    if (_Py_INIT_FAILED(err)) {
-        goto error;
-    }
-
-    err = _PyPathConfig_Init(&config);
-    if (_Py_INIT_FAILED(err)) {
-        goto error;
-    }
-
-    _PyMainInterpreterConfig_Clear(&config);
-    return;
-
-error:
-    _PyMainInterpreterConfig_Clear(&config);
-    _Py_FatalInitError(err);
-}
-
-
-/* External interface */
-
-void
-Py_SetPath(const wchar_t *path)
-{
-    if (path == NULL) {
-        _PyPathConfig_Clear(&_Py_path_config);
-        return;
-    }
-
-    PyMemAllocatorEx old_alloc;
-    _PyMem_SetDefaultAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
-
-    _PyPathConfig new_config;
-    new_config.program_full_path = _PyMem_RawWcsdup(Py_GetProgramName());
-    new_config.prefix = _PyMem_RawWcsdup(L"");
-#ifdef MS_WINDOWS
-    new_config.dll_path = _PyMem_RawWcsdup(L"");
-#else
-    new_config.exec_prefix = _PyMem_RawWcsdup(L"");
-#endif
-    new_config.module_search_path = _PyMem_RawWcsdup(path);
-
-    /* steal the home and program_name values (to leave them unchanged) */
-    new_config.home = _Py_path_config.home;
-    _Py_path_config.home = NULL;
-    new_config.program_name = _Py_path_config.program_name;
-    _Py_path_config.program_name = NULL;
-
-    _PyPathConfig_Clear(&_Py_path_config);
-    _Py_path_config = new_config;
-
-    PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
-}
-
-
-void
-Py_SetPythonHome(wchar_t *home)
-{
-    if (home == NULL) {
-        return;
-    }
-
-    PyMemAllocatorEx old_alloc;
-    _PyMem_SetDefaultAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
-
-    PyMem_RawFree(_Py_path_config.home);
-    _Py_path_config.home = _PyMem_RawWcsdup(home);
-
-    PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
-
-    if (_Py_path_config.home == NULL) {
-        Py_FatalError("Py_SetPythonHome() failed: out of memory");
-    }
-}
-
-
-void
-Py_SetProgramName(wchar_t *program_name)
-{
-    if (program_name == NULL || program_name[0] == L'\0') {
-        return;
-    }
-
-    PyMemAllocatorEx old_alloc;
-    _PyMem_SetDefaultAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
-
-    PyMem_RawFree(_Py_path_config.program_name);
-    _Py_path_config.program_name = _PyMem_RawWcsdup(program_name);
-
-    PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
-
-    if (_Py_path_config.program_name == NULL) {
-        Py_FatalError("Py_SetProgramName() failed: out of memory");
-    }
-}
-
-
-wchar_t *
-Py_GetPath(void)
-{
-    pathconfig_global_init();
-    return _Py_path_config.module_search_path;
-}
-
-
-wchar_t *
-Py_GetPrefix(void)
-{
-    pathconfig_global_init();
-    return _Py_path_config.prefix;
-}
-
-
-wchar_t *
-Py_GetExecPrefix(void)
-{
-#ifdef MS_WINDOWS
-    return Py_GetPrefix();
-#else
-    pathconfig_global_init();
-    return _Py_path_config.exec_prefix;
-#endif
-}
-
-
-wchar_t *
-Py_GetProgramFullPath(void)
-{
-    pathconfig_global_init();
-    return _Py_path_config.program_full_path;
-}
-
-
-wchar_t*
-Py_GetPythonHome(void)
-{
-    pathconfig_global_init();
-    return _Py_path_config.home;
-}
-
-
-wchar_t *
-Py_GetProgramName(void)
-{
-    pathconfig_global_init();
-    return _Py_path_config.program_name;
-}
-
-
-#ifdef __cplusplus
-}
-#endif

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