Merge branch 'main' into capi-PySys_GetAttr3

Author: serhiy-storchaka

Doc/c-api/exceptions.rst

@@ -921,11 +921,7 @@ because the :ref:`call protocol <call>` takes care of recursion handling.
 
    Marks a point where a recursive C-level call is about to be performed.
 
-   If :c:macro:`!USE_STACKCHECK` is defined, this function checks if the OS
-   stack overflowed using :c:func:`PyOS_CheckStack`.  If this is the case, it
-   sets a :exc:`MemoryError` and returns a nonzero value.
-
-   The function then checks if the recursion limit is reached.  If this is the
+   The function then checks if the stack limit is reached.  If this is the
    case, a :exc:`RecursionError` is set and a nonzero value is returned.
    Otherwise, zero is returned.
 

Doc/c-api/module.rst

@@ -415,7 +415,7 @@ The available slot types are:
    in one module definition.
 
    If ``Py_mod_multiple_interpreters`` is not specified, the import
-   machinery defaults to ``Py_MOD_MULTIPLE_INTERPRETERS_NOT_SUPPORTED``.
+   machinery defaults to ``Py_MOD_MULTIPLE_INTERPRETERS_SUPPORTED``.
 
    .. versionadded:: 3.12
 

Doc/c-api/unicode.rst

@@ -607,6 +607,15 @@ APIs:
    decref'ing the returned objects.
 
 
+.. c:function:: const char* PyUnicode_GetDefaultEncoding(void)
+
+   Return the name of the default string encoding, ``"utf-8"``.
+   See :func:`sys.getdefaultencoding`.
+
+   The returned string does not need to be freed, and is valid
+   until interpreter shutdown.
+
+
 .. c:function:: Py_ssize_t PyUnicode_GetLength(PyObject *unicode)
 
    Return the length of the Unicode object, in code points.

Doc/data/refcounts.dat

@@ -2770,6 +2770,9 @@ PyUnicode_FromFormatV:PyObject*::+1:
 PyUnicode_FromFormatV:const char*:format::
 PyUnicode_FromFormatV:va_list:args::
 
+PyUnicode_GetDefaultEncoding:const char*:::
+PyUnicode_GetDefaultEncoding::void::
+
 PyUnicode_GetLength:Py_ssize_t:::
 PyUnicode_GetLength:PyObject*:unicode:0:
 

Doc/library/sys.rst

@@ -771,8 +771,8 @@ always available. Unless explicitly noted otherwise, all variables are read-only
 
 .. function:: getdefaultencoding()
 
-   Return the name of the current default string encoding used by the Unicode
-   implementation.
+   Return ``'utf-8'``. This is the name of the default string encoding, used
+   in methods like :meth:`str.encode`.
 
 
 .. function:: getdlopenflags()

Doc/library/wsgiref.rst

@@ -119,7 +119,8 @@ in type annotations.
    applications to set up dummy environments.  It should NOT be used by actual WSGI
    servers or applications, since the data is fake!
 
-   Example usage::
+   Example usage (see also :func:`~wsgiref.simple_server.demo_app`
+   for another example)::
 
       from wsgiref.util import setup_testing_defaults
       from wsgiref.simple_server import make_server
@@ -312,6 +313,8 @@ request.  (E.g., using the :func:`shift_path_info` function from
    as :mod:`wsgiref.simple_server`) is able to run a simple WSGI application
    correctly.
 
+   The *start_response* callable should follow the :class:`.StartResponse` protocol.
+
 
 .. class:: WSGIServer(server_address, RequestHandlerClass)
 
@@ -679,7 +682,9 @@ input, output, and error streams.
 
       This method can access the current error using ``sys.exception()``,
       and should pass that information to *start_response* when calling it (as
-      described in the "Error Handling" section of :pep:`3333`).
+      described in the "Error Handling" section of :pep:`3333`). In particular,
+      the *start_response* callable should follow the :class:`.StartResponse`
+      protocol.
 
       The default implementation just uses the :attr:`error_status`,
       :attr:`error_headers`, and :attr:`error_body` attributes to generate an output
@@ -781,7 +786,7 @@ in :pep:`3333`.
 .. versionadded:: 3.11
 
 
-.. class:: StartResponse()
+.. class:: StartResponse
 
    A :class:`typing.Protocol` describing :pep:`start_response()
    <3333#the-start-response-callable>`
@@ -816,7 +821,8 @@ in :pep:`3333`.
 Examples
 --------
 
-This is a working "Hello World" WSGI application::
+This is a working "Hello World" WSGI application, where the *start_response*
+callable should follow the :class:`.StartResponse` protocol::
 
    """
    Every WSGI application must have an application object - a callable

Include/cpython/object.h

@@ -487,18 +487,19 @@ PyAPI_FUNC(void) _PyTrash_thread_destroy_chain(PyThreadState *tstate);
  * we have headroom above the trigger limit */
 #define Py_TRASHCAN_HEADROOM 50
 
+/* Helper function for Py_TRASHCAN_BEGIN */
+PyAPI_FUNC(int) _Py_ReachedRecursionLimitWithMargin(PyThreadState *tstate, int margin_count);
+
 #define Py_TRASHCAN_BEGIN(op, dealloc) \
 do { \
     PyThreadState *tstate = PyThreadState_Get(); \
-    if (tstate->c_recursion_remaining <= Py_TRASHCAN_HEADROOM && Py_TYPE(op)->tp_dealloc == (destructor)dealloc) { \
+    if (_Py_ReachedRecursionLimitWithMargin(tstate, 1) && Py_TYPE(op)->tp_dealloc == (destructor)dealloc) { \
         _PyTrash_thread_deposit_object(tstate, (PyObject *)op); \
         break; \
-    } \
-    tstate->c_recursion_remaining--;
+    }
     /* The body of the deallocator is here. */
 #define Py_TRASHCAN_END \
-    tstate->c_recursion_remaining++; \
-    if (tstate->delete_later && tstate->c_recursion_remaining > (Py_TRASHCAN_HEADROOM*2)) { \
+    if (tstate->delete_later && !_Py_ReachedRecursionLimitWithMargin(tstate, 2)) { \
         _PyTrash_thread_destroy_chain(tstate); \
     } \
 } while (0);

Include/cpython/pystate.h

@@ -112,7 +112,7 @@ struct _ts {
     int py_recursion_remaining;
     int py_recursion_limit;
 
-    int c_recursion_remaining;
+    int c_recursion_remaining; /* Retained for backwards compatibility. Do not use */
     int recursion_headroom; /* Allow 50 more calls to handle any errors. */
 
     /* 'tracing' keeps track of the execution depth when tracing/profiling.
@@ -202,36 +202,7 @@ struct _ts {
     PyObject *threading_local_sentinel;
 };
 
-#ifdef Py_DEBUG
-   // A debug build is likely built with low optimization level which implies
-   // higher stack memory usage than a release build: use a lower limit.
-#  define Py_C_RECURSION_LIMIT 500
-#elif defined(__s390x__)
-#  define Py_C_RECURSION_LIMIT 800
-#elif defined(_WIN32) && defined(_M_ARM64)
-#  define Py_C_RECURSION_LIMIT 1000
-#elif defined(_WIN32)
-#  define Py_C_RECURSION_LIMIT 3000
-#elif defined(__ANDROID__)
-   // On an ARM64 emulator, API level 34 was OK with 10000, but API level 21
-   // crashed in test_compiler_recursion_limit.
-#  define Py_C_RECURSION_LIMIT 3000
-#elif defined(_Py_ADDRESS_SANITIZER)
-#  define Py_C_RECURSION_LIMIT 4000
-#elif defined(__sparc__)
-   // test_descr crashed on sparc64 with >7000 but let's keep a margin of error.
-#  define Py_C_RECURSION_LIMIT 4000
-#elif defined(__wasi__)
-   // Based on wasmtime 16.
-#  define Py_C_RECURSION_LIMIT 5000
-#elif defined(__hppa__) || defined(__powerpc64__)
-   // test_descr crashed with >8000 but let's keep a margin of error.
-#  define Py_C_RECURSION_LIMIT 5000
-#else
-   // This value is duplicated in Lib/test/support/__init__.py
-#  define Py_C_RECURSION_LIMIT 10000
-#endif
-
+# define Py_C_RECURSION_LIMIT 5000
 
 /* other API */
 
@@ -246,7 +217,6 @@ _PyThreadState_UncheckedGet(void)
     return PyThreadState_GetUnchecked();
 }
 
-
 // Disable tracing and profiling.
 PyAPI_FUNC(void) PyThreadState_EnterTracing(PyThreadState *tstate);
 

Include/internal/pycore_ceval.h

@@ -193,18 +193,28 @@ extern void _PyEval_DeactivateOpCache(void);
 
 /* --- _Py_EnterRecursiveCall() ----------------------------------------- */
 
-#ifdef USE_STACKCHECK
-/* With USE_STACKCHECK macro defined, trigger stack checks in
-   _Py_CheckRecursiveCall() on every 64th call to _Py_EnterRecursiveCall. */
-static inline int _Py_MakeRecCheck(PyThreadState *tstate)  {
-    return (tstate->c_recursion_remaining-- < 0
-            || (tstate->c_recursion_remaining & 63) == 0);
+#if !_Py__has_builtin(__builtin_frame_address)
+static uintptr_t return_pointer_as_int(char* p) {
+    return (uintptr_t)p;
 }
+#endif
+
+static inline uintptr_t
+_Py_get_machine_stack_pointer(void) {
+#if _Py__has_builtin(__builtin_frame_address)
+    return (uintptr_t)__builtin_frame_address(0);
 #else
-static inline int _Py_MakeRecCheck(PyThreadState *tstate) {
-    return tstate->c_recursion_remaining-- < 0;
-}
+    char here;
+    /* Avoid compiler warning about returning stack address */
+    return return_pointer_as_int(&here);
 #endif
+}
+
+static inline int _Py_MakeRecCheck(PyThreadState *tstate)  {
+    uintptr_t here_addr = _Py_get_machine_stack_pointer();
+    _PyThreadStateImpl *_tstate = (_PyThreadStateImpl *)tstate;
+    return here_addr < _tstate->c_stack_soft_limit;
+}
 
 // Export for '_json' shared extension, used via _Py_EnterRecursiveCall()
 // static inline function.
@@ -220,23 +230,30 @@ static inline int _Py_EnterRecursiveCallTstate(PyThreadState *tstate,
     return (_Py_MakeRecCheck(tstate) && _Py_CheckRecursiveCall(tstate, where));
 }
 
-static inline void _Py_EnterRecursiveCallTstateUnchecked(PyThreadState *tstate)  {
-    assert(tstate->c_recursion_remaining > 0);
-    tstate->c_recursion_remaining--;
-}
-
 static inline int _Py_EnterRecursiveCall(const char *where) {
     PyThreadState *tstate = _PyThreadState_GET();
     return _Py_EnterRecursiveCallTstate(tstate, where);
 }
 
-static inline void _Py_LeaveRecursiveCallTstate(PyThreadState *tstate)  {
-    tstate->c_recursion_remaining++;
+static inline void _Py_LeaveRecursiveCallTstate(PyThreadState *tstate) {
+    (void)tstate;
+}
+
+PyAPI_FUNC(void) _Py_InitializeRecursionLimits(PyThreadState *tstate);
+
+static inline int _Py_ReachedRecursionLimit(PyThreadState *tstate)  {
+    uintptr_t here_addr = _Py_get_machine_stack_pointer();
+    _PyThreadStateImpl *_tstate = (_PyThreadStateImpl *)tstate;
+    if (here_addr > _tstate->c_stack_soft_limit) {
+        return 0;
+    }
+    if (_tstate->c_stack_hard_limit == 0) {
+        _Py_InitializeRecursionLimits(tstate);
+    }
+    return here_addr <= _tstate->c_stack_soft_limit;
 }
 
 static inline void _Py_LeaveRecursiveCall(void)  {
-    PyThreadState *tstate = _PyThreadState_GET();
-    _Py_LeaveRecursiveCallTstate(tstate);
 }
 
 extern struct _PyInterpreterFrame* _PyEval_GetFrame(void);
@@ -327,7 +344,6 @@ void _Py_unset_eval_breaker_bit_all(PyInterpreterState *interp, uintptr_t bit);
 
 PyAPI_FUNC(PyObject *) _PyFloat_FromDouble_ConsumeInputs(_PyStackRef left, _PyStackRef right, double value);
 
-
 #ifdef __cplusplus
 }
 #endif

Include/internal/pycore_symtable.h

@@ -82,8 +82,6 @@ struct symtable {
     PyObject *st_private;           /* name of current class or NULL */
     _PyFutureFeatures *st_future;   /* module's future features that affect
                                        the symbol table */
-    int recursion_depth;            /* current recursion depth */
-    int recursion_limit;            /* recursion limit */
 };
 
 typedef struct _symtable_entry {