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

* Factorize code from PC/getpathp.c and Modules/getpath.c to remove
  duplicated code
* rename pathconfig_clear() to _PyPathConfig_Clear()
* Inline _PyPathConfig_Fini() in pymain_impl() and then remove it,
  since it's a oneliner

Include/internal/pystate.h

@@ -52,6 +52,10 @@ typedef struct {
 
 #define _PyPathConfig_INIT {.module_search_path = NULL}
 
+PyAPI_DATA(_PyPathConfig) _Py_path_config;
+
+PyAPI_FUNC(void) _PyPathConfig_Clear(_PyPathConfig *config);
+
 
 /* Full Python runtime state */
 

Include/pylifecycle.h

@@ -105,7 +105,6 @@ 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

Makefile.pre.in

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

Modules/getpath.c

@@ -132,7 +132,6 @@ typedef struct {
 
 static const wchar_t delimiter[2] = {DELIM, '\0'};
 static const wchar_t separator[2] = {SEP, '\0'};
-static _PyPathConfig _Py_path_config = _PyPathConfig_INIT;
 
 
 /* Get file status. Encode the path to the locale encoding. */
@@ -1009,23 +1008,6 @@ calculate_path_impl(const _PyMainInterpreterConfig *main_config,
 }
 
 
-static void
-pathconfig_clear(_PyPathConfig *config)
-{
-#define CLEAR(ATTR) \
-    do { \
-        PyMem_RawFree(ATTR); \
-        ATTR = NULL; \
-    } while (0)
-
-    CLEAR(config->prefix);
-    CLEAR(config->exec_prefix);
-    CLEAR(config->program_full_path);
-    CLEAR(config->module_search_path);
-#undef CLEAR
-}
-
-
 /* Initialize paths for Py_GetPath(), Py_GetPrefix(), Py_GetExecPrefix()
    and Py_GetProgramFullPath() */
 _PyInitError
@@ -1049,7 +1031,7 @@ _PyPathConfig_Init(const _PyMainInterpreterConfig *main_config)
 
     err = calculate_path_impl(main_config, &calculate, &new_path_config);
     if (_Py_INIT_FAILED(err)) {
-        pathconfig_clear(&new_path_config);
+        _PyPathConfig_Clear(&new_path_config);
         goto done;
     }
 
@@ -1061,100 +1043,6 @@ done:
     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);
-}
-
-
-void
-_PyPathConfig_Fini(void)
-{
-    pathconfig_clear(&_Py_path_config);
-}
-
-
-/* External interface */
-void
-Py_SetPath(const wchar_t *path)
-{
-    if (path == NULL) {
-        pathconfig_clear(&_Py_path_config);
-        return;
-    }
-
-    _PyPathConfig new_config;
-    new_config.program_full_path = _PyMem_RawWcsdup(Py_GetProgramName());
-    new_config.exec_prefix = _PyMem_RawWcsdup(L"");
-    new_config.prefix = _PyMem_RawWcsdup(L"");
-    new_config.module_search_path = _PyMem_RawWcsdup(path);
-
-    pathconfig_clear(&_Py_path_config);
-    _Py_path_config = new_config;
-}
-
-
-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)
-{
-    pathconfig_global_init();
-    return _Py_path_config.exec_prefix;
-}
-
-
-wchar_t *
-Py_GetProgramFullPath(void)
-{
-    pathconfig_global_init();
-    return _Py_path_config.program_full_path;
-}
-
 #ifdef __cplusplus
 }
 #endif

Modules/main.c

@@ -1665,12 +1665,12 @@ pymain_impl(_PyMain *pymain)
         pymain->status = 120;
     }
 
-    /* _PyPathConfig_Fini() cannot be called in Py_FinalizeEx().
+    /* _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_Fini() clear all these
+       Py_SetPythonHome(), whereas _PyPathConfig_Clear() clear all these
        parameters. */
-    _PyPathConfig_Fini();
+    _PyPathConfig_Clear(&_Py_path_config);
 
     return 0;
 }

PC/getpathp.c

@@ -130,9 +130,6 @@ typedef struct {
 } PyCalculatePath;
 
 
-static _PyPathConfig _Py_path_config = _PyPathConfig_INIT;
-
-
 /* determine if "ch" is a separator character */
 static int
 is_sep(wchar_t ch)
@@ -1061,23 +1058,6 @@ calculate_free(PyCalculatePath *calculate)
 }
 
 
-static void
-pathconfig_clear(_PyPathConfig *config)
-{
-#define CLEAR(ATTR) \
-    do { \
-        PyMem_RawFree(ATTR); \
-        ATTR = NULL; \
-    } while (0)
-
-    CLEAR(config->prefix);
-    CLEAR(config->program_full_path);
-    CLEAR(config->dll_path);
-    CLEAR(config->module_search_path);
-#undef CLEAR
-}
-
-
 /* Initialize paths for Py_GetPath(), Py_GetPrefix(), Py_GetExecPrefix()
    and Py_GetProgramFullPath() */
 _PyInitError
@@ -1108,110 +1088,13 @@ _PyPathConfig_Init(const _PyMainInterpreterConfig *main_config)
 
 done:
     if (_Py_INIT_FAILED(err)) {
-        pathconfig_clear(&new_path_config);
+        _PyPathConfig_Clear(&new_path_config);
     }
     calculate_free(&calculate);
     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);
-}
-
-
-void
-_PyPathConfig_Fini(void)
-{
-    pathconfig_clear(&_Py_path_config);
-}
-
-
-/* External interface */
-
-void
-Py_SetPath(const wchar_t *path)
-{
-    if (_Py_path_config.module_search_path != NULL) {
-        pathconfig_clear(&_Py_path_config);
-    }
-
-    if (path == NULL) {
-        return;
-    }
-
-    _PyPathConfig new_config;
-    new_config.program_full_path = _PyMem_RawWcsdup(Py_GetProgramName());
-    new_config.prefix = _PyMem_RawWcsdup(L"");
-    new_config.dll_path = _PyMem_RawWcsdup(L"");
-    new_config.module_search_path = _PyMem_RawWcsdup(path);
-
-    pathconfig_clear(&_Py_path_config);
-    _Py_path_config = new_config;
-}
-
-
-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)
-{
-    return Py_GetPrefix();
-}
-
-
-wchar_t *
-Py_GetProgramFullPath(void)
-{
-    pathconfig_global_init();
-    return _Py_path_config.program_full_path;
-}
-
-
 /* Load python3.dll before loading any extension module that might refer
    to it. That way, we can be sure that always the python3.dll corresponding
    to this python DLL is loaded, not a python3.dll that might be on the path

PCbuild/pythoncore.vcxproj

@@ -381,6 +381,7 @@
     <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

@@ -896,6 +896,9 @@
     <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

@@ -0,0 +1,189 @@
+/* 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;
+#ifdef MS_WINDOWS
+static wchar_t *progname = L"python";
+#else
+static wchar_t *progname = L"python3";
+#endif
+static wchar_t *default_home = NULL;
+
+
+void
+_PyPathConfig_Clear(_PyPathConfig *config)
+{
+#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);
+#undef CLEAR
+}
+
+
+void
+Py_SetProgramName(wchar_t *pn)
+{
+    if (pn && *pn)
+        progname = pn;
+}
+
+
+wchar_t *
+Py_GetProgramName(void)
+{
+    return progname;
+}
+
+
+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;
+}
+
+
+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;
+    }
+
+    _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);
+
+    _PyPathConfig_Clear(&_Py_path_config);
+    _Py_path_config = new_config;
+}
+
+
+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;
+}
+
+#ifdef __cplusplus
+}
+#endif

Python/pylifecycle.c

@@ -1489,61 +1489,6 @@ 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