bpo-22257: Private C-API for core runtime initialization (PEP 432). (#1772)

(patch by Nick Coghlan)

Include/pylifecycle.h

@@ -19,8 +19,14 @@ PyAPI_FUNC(wchar_t *) Py_GetPythonHome(void);
  */
 PyAPI_FUNC(int) Py_SetStandardStreamEncoding(const char *encoding,
                                              const char *errors);
+
+/* PEP 432 Multi-phase initialization API (Private while provisional!) */
+PyAPI_FUNC(void) _Py_InitializeCore(const _PyCoreConfig *);
+PyAPI_FUNC(int) _Py_IsCoreInitialized(void);
+PyAPI_FUNC(int) _Py_InitializeMainInterpreter(int install_sigs);
 #endif
 
+/* Initialization and finalization */
 PyAPI_FUNC(void) Py_Initialize(void);
 PyAPI_FUNC(void) Py_InitializeEx(int);
 #ifndef Py_LIMITED_API
@@ -29,6 +35,8 @@ PyAPI_FUNC(void) _Py_InitializeEx_Private(int, int);
 PyAPI_FUNC(void) Py_Finalize(void);
 PyAPI_FUNC(int) Py_FinalizeEx(void);
 PyAPI_FUNC(int) Py_IsInitialized(void);
+
+/* Subinterpreter support */
 PyAPI_FUNC(PyThreadState *) Py_NewInterpreter(void);
 PyAPI_FUNC(void) Py_EndInterpreter(PyThreadState *);
 
@@ -85,7 +93,7 @@ PyAPI_FUNC(void) _PyImportHooks_Init(void);
 PyAPI_FUNC(int) _PyFrame_Init(void);
 PyAPI_FUNC(int) _PyFloat_Init(void);
 PyAPI_FUNC(int) PyByteArray_Init(void);
-PyAPI_FUNC(void) _Py_HashRandomization_Init(void);
+PyAPI_FUNC(void) _Py_HashRandomization_Init(_PyCoreConfig *core_config);
 #endif
 
 /* Various internal finalizers */

Include/pystate.h

@@ -23,6 +23,16 @@ typedef struct _is PyInterpreterState;
 #else
 typedef PyObject* (*_PyFrameEvalFunction)(struct _frame *, int);
 
+
+typedef struct {
+    int ignore_environment;
+    int use_hash_seed;
+    unsigned long hash_seed;
+    int _disable_importlib; /* Needed by freeze_importlib */
+} _PyCoreConfig;
+
+#define _PyCoreConfig_INIT {0, -1, 0, 0}
+
 typedef struct _is {
 
     struct _is *next;
@@ -42,6 +52,7 @@ typedef struct _is {
     int codecs_initialized;
     int fscodec_initialized;
 
+    _PyCoreConfig core_config;
 #ifdef HAVE_DLOPEN
     int dlopenflags;
 #endif

Modules/main.c

@@ -380,19 +380,6 @@ read_command_line(int argc, wchar_t **argv, _Py_CommandLineDetails *cmdline)
     wchar_t *command = NULL;
     wchar_t *module = NULL;
     int c;
-    char *opt;
-
-    opt = Py_GETENV("PYTHONMALLOC");
-    if (_PyMem_SetupAllocators(opt) < 0) {
-        fprintf(stderr,
-                "Error in PYTHONMALLOC: unknown allocator \"%s\"!\n", opt);
-        exit(1);
-    }
-
-	// TODO: Move these to core runtime init.
-    Py_HashRandomizationFlag = 1;
-    _Py_HashRandomization_Init();
-    PySys_ResetWarnOptions();
 
     _PyOS_ResetGetOpt();
 
@@ -584,6 +571,7 @@ Py_Main(int argc, wchar_t **argv)
 #endif
     int stdin_is_interactive = 0;
     _Py_CommandLineDetails cmdline = _Py_CommandLineDetails_INIT;
+    _PyCoreConfig core_config = _PyCoreConfig_INIT;
     PyCompilerFlags cf;
     PyObject *main_importer_path = NULL;
 
@@ -602,11 +590,23 @@ Py_Main(int argc, wchar_t **argv)
             break;
         }
         if (c == 'E' || c == 'I') {
-            Py_IgnoreEnvironmentFlag++;
+            core_config.ignore_environment++;
             break;
         }
     }
 
+    char *pymalloc = Py_GETENV("PYTHONMALLOC");
+    if (_PyMem_SetupAllocators(pymalloc) < 0) {
+        fprintf(stderr,
+            "Error in PYTHONMALLOC: unknown allocator \"%s\"!\n", pymalloc);
+        exit(1);
+    }
+
+    /* Initialize the core language runtime */
+    Py_IgnoreEnvironmentFlag = core_config.ignore_environment;
+    core_config._disable_importlib = 0;
+    _Py_InitializeCore(&core_config);
+
     /* Reprocess the command line with the language runtime available */
     if (read_command_line(argc, argv, &cmdline)) {
         return usage(2, argv[0]);
@@ -680,6 +680,7 @@ Py_Main(int argc, wchar_t **argv)
         for (i = 0; i < PyList_GET_SIZE(cmdline.warning_options); i++) {
             PySys_AddWarnOptionUnicode(PyList_GET_ITEM(cmdline.warning_options, i));
         }
+        Py_DECREF(cmdline.warning_options);
     }
 
     stdin_is_interactive = Py_FdIsInteractive(stdin, (char *)0);
@@ -767,9 +768,10 @@ Py_Main(int argc, wchar_t **argv)
 #else
     Py_SetProgramName(argv[0]);
 #endif
-    Py_Initialize();
-    Py_XDECREF(cmdline.warning_options);
+    if (_Py_InitializeMainInterpreter(1))
+        Py_FatalError("Py_Main: Py_InitializeMainInterpreter failed");
 
+    /* TODO: Move this to _PyRun_PrepareMain */
     if (!Py_QuietFlag && (Py_VerboseFlag ||
                         (cmdline.command == NULL && cmdline.filename == NULL &&
                          cmdline.module == NULL && stdin_is_interactive))) {
@@ -779,6 +781,7 @@ Py_Main(int argc, wchar_t **argv)
             fprintf(stderr, "%s\n", COPYRIGHT);
     }
 
+    /* TODO: Move this to _Py_InitializeMainInterpreter */
     if (cmdline.command != NULL) {
         /* Backup _PyOS_optind and force sys.argv[0] = '-c' */
         _PyOS_optind--;

Python/bootstrap_hash.c

@@ -599,11 +599,11 @@ init_hash_secret(int use_hash_seed,
 }
 
 void
-_Py_HashRandomization_Init(void)
+_Py_HashRandomization_Init(_PyCoreConfig *core_config)
 {
     char *seed_text;
-    int use_hash_seed = -1;
-    unsigned long hash_seed;
+    int use_hash_seed = core_config->use_hash_seed;
+    unsigned long hash_seed = core_config->hash_seed;
 
     if (use_hash_seed < 0) {
         seed_text = Py_GETENV("PYTHONHASHSEED");
@@ -611,6 +611,8 @@ _Py_HashRandomization_Init(void)
             Py_FatalError("PYTHONHASHSEED must be \"random\" or an integer "
                           "in range [0; 4294967295]");
         }
+        core_config->use_hash_seed = use_hash_seed;
+        core_config->hash_seed = hash_seed;
     }
     init_hash_secret(use_hash_seed, hash_seed);
 }