11 files changed, 108 insertions, 24 deletions
diff --git a/Include/internal/mimalloc/mimalloc/internal.h b/Include/internal/mimalloc/mimalloc/internal.h
index 71b7ea702d6..a7daa3a40a4 100644
--- a/Include/internal/mimalloc/mimalloc/internal.h
+++ b/Include/internal/mimalloc/mimalloc/internal.h
@@ -634,10 +634,10 @@ static inline mi_block_t* mi_block_nextx( const void* null, const mi_block_t* bl
   mi_track_mem_defined(block,sizeof(mi_block_t));
   mi_block_t* next;
   #ifdef MI_ENCODE_FREELIST
-  next = (mi_block_t*)mi_ptr_decode(null, mi_atomic_load_relaxed(&block->next), keys);
+  next = (mi_block_t*)mi_ptr_decode(null, mi_atomic_load_relaxed((_Atomic(mi_encoded_t)*)&block->next), keys);
   #else
   MI_UNUSED(keys); MI_UNUSED(null);
-  next = (mi_block_t*)mi_atomic_load_relaxed(&block->next);
+  next = (mi_block_t*)mi_atomic_load_relaxed((_Atomic(mi_encoded_t)*)&block->next);
   #endif
   mi_track_mem_noaccess(block,sizeof(mi_block_t));
   return next;
diff --git a/Include/internal/mimalloc/mimalloc/types.h b/Include/internal/mimalloc/mimalloc/types.h
index 4f77bd7bc52..a04169f7fb8 100644
--- a/Include/internal/mimalloc/mimalloc/types.h
+++ b/Include/internal/mimalloc/mimalloc/types.h
@@ -50,6 +50,32 @@ terms of the MIT license. A copy of the license can be found in the file
 #define mi_decl_cache_align
 #endif
 
+#if (MI_DEBUG)
+#if defined(_MSC_VER)
+#define mi_decl_noreturn        __declspec(noreturn)
+#elif (defined(__GNUC__) && (__GNUC__ >= 3)) || defined(__clang__)
+#define mi_decl_noreturn        __attribute__((__noreturn__))
+#else
+#define mi_decl_noreturn
+#endif
+
+/*
+ * 'cold' attribute seems to have been fully supported since GCC 4.x.
+ * See https://github.com/gcc-mirror/gcc/commit/52bf96d2f299e9e6.
+ */
+#if (defined(__GNUC__) && (__GNUC__ >= 4)) || defined(__clang__)
+#define mi_decl_cold            __attribute__((cold))
+#else
+#define mi_decl_cold
+#endif
+
+#if (defined(__GNUC__) && defined(__THROW))
+#define mi_decl_throw           __THROW
+#else
+#define mi_decl_throw
+#endif
+#endif
+
 // ------------------------------------------------------
 // Variants
 // ------------------------------------------------------
@@ -582,7 +608,8 @@ struct mi_heap_s {
 
 #if (MI_DEBUG)
 // use our own assertion to print without memory allocation
-void _mi_assert_fail(const char* assertion, const char* fname, unsigned int line, const char* func );
+mi_decl_noreturn mi_decl_cold mi_decl_throw
+void _mi_assert_fail(const char* assertion, const char* fname, unsigned int line, const char* func);
 #define mi_assert(expr)     ((expr) ? (void)0 : _mi_assert_fail(#expr,__FILE__,__LINE__,__func__))
 #else
 #define mi_assert(x)
diff --git a/Include/internal/pycore_ceval.h b/Include/internal/pycore_ceval.h
index 092feeb40b0..239177deb4a 100644
--- a/Include/internal/pycore_ceval.h
+++ b/Include/internal/pycore_ceval.h
@@ -353,7 +353,8 @@ PyAPI_FUNC(_PyStackRef) _PyFloat_FromDouble_ConsumeInputs(_PyStackRef left, _PyS
 extern int _PyRunRemoteDebugger(PyThreadState *tstate);
 #endif
 
-_PyStackRef _PyForIter_NextWithIndex(PyObject *seq, _PyStackRef index);
+PyAPI_FUNC(_PyStackRef)
+_PyForIter_VirtualIteratorNext(PyThreadState* tstate, struct _PyInterpreterFrame* frame, _PyStackRef iter, _PyStackRef *index_ptr);
 
 #ifdef __cplusplus
 }
diff --git a/Include/internal/pycore_crossinterp.h b/Include/internal/pycore_crossinterp.h
index 12729274138..713ddc66ba7 100644
--- a/Include/internal/pycore_crossinterp.h
+++ b/Include/internal/pycore_crossinterp.h
@@ -317,7 +317,9 @@ typedef enum error_code {
     _PyXI_ERR_ALREADY_RUNNING = -4,
     _PyXI_ERR_MAIN_NS_FAILURE = -5,
     _PyXI_ERR_APPLY_NS_FAILURE = -6,
-    _PyXI_ERR_NOT_SHAREABLE = -7,
+    _PyXI_ERR_PRESERVE_FAILURE = -7,
+    _PyXI_ERR_EXC_PROPAGATION_FAILURE = -8,
+    _PyXI_ERR_NOT_SHAREABLE = -9,
 } _PyXI_errcode;
 
 
@@ -350,16 +352,33 @@ typedef struct xi_session _PyXI_session;
 PyAPI_FUNC(_PyXI_session *) _PyXI_NewSession(void);
 PyAPI_FUNC(void) _PyXI_FreeSession(_PyXI_session *);
 
+typedef struct {
+    PyObject *preserved;
+    PyObject *excinfo;
+    _PyXI_errcode errcode;
+} _PyXI_session_result;
+PyAPI_FUNC(void) _PyXI_ClearResult(_PyXI_session_result *);
+
 PyAPI_FUNC(int) _PyXI_Enter(
     _PyXI_session *session,
     PyInterpreterState *interp,
-    PyObject *nsupdates);
-PyAPI_FUNC(void) _PyXI_Exit(_PyXI_session *session);
-
-PyAPI_FUNC(PyObject *) _PyXI_GetMainNamespace(_PyXI_session *);
-
-PyAPI_FUNC(PyObject *) _PyXI_ApplyCapturedException(_PyXI_session *session);
-PyAPI_FUNC(int) _PyXI_HasCapturedException(_PyXI_session *session);
+    PyObject *nsupdates,
+    _PyXI_session_result *);
+PyAPI_FUNC(int) _PyXI_Exit(
+    _PyXI_session *,
+    _PyXI_errcode,
+    _PyXI_session_result *);
+
+PyAPI_FUNC(PyObject *) _PyXI_GetMainNamespace(
+    _PyXI_session *,
+    _PyXI_errcode *);
+
+PyAPI_FUNC(int) _PyXI_Preserve(
+    _PyXI_session *,
+    const char *,
+    PyObject *,
+    _PyXI_errcode *);
+PyAPI_FUNC(PyObject *) _PyXI_GetPreserved(_PyXI_session_result *, const char *);
 
 
 /*************/
diff --git a/Include/internal/pycore_interp_structs.h b/Include/internal/pycore_interp_structs.h
index 8a29c533b99..f25f5847b3b 100644
--- a/Include/internal/pycore_interp_structs.h
+++ b/Include/internal/pycore_interp_structs.h
@@ -677,8 +677,11 @@ struct _Py_interp_cached_objects {
 
     /* object.__reduce__ */
     PyObject *objreduce;
+#ifndef Py_GIL_DISABLED
+    /* resolve_slotdups() */
     PyObject *type_slots_pname;
     pytype_slotdef *type_slots_ptrs[MAX_EQUIV];
+#endif
 
     /* TypeVar and related types */
     PyTypeObject *generic_type;
diff --git a/Include/internal/pycore_lock.h b/Include/internal/pycore_lock.h
index 7484b05d7f2..32b60cc33a2 100644
--- a/Include/internal/pycore_lock.h
+++ b/Include/internal/pycore_lock.h
@@ -48,6 +48,9 @@ typedef enum _PyLockFlags {
 
     // Handle signals if interrupted while waiting on the lock.
     _PY_LOCK_HANDLE_SIGNALS = 2,
+
+    // Fail if interrupted by a signal while waiting on the lock.
+    _PY_FAIL_IF_INTERRUPTED = 4,
 } _PyLockFlags;
 
 // Lock a mutex with an optional timeout and additional options. See
diff --git a/Include/internal/pycore_magic_number.h b/Include/internal/pycore_magic_number.h
index cd1fc873623..347d9762f26 100644
--- a/Include/internal/pycore_magic_number.h
+++ b/Include/internal/pycore_magic_number.h
@@ -280,6 +280,7 @@ Known values:
     Python 3.15a0 3650 (Initial version)
     Python 3.15a1 3651 (Simplify LOAD_CONST)
     Python 3.15a1 3652 (Virtual iterators)
+    Python 3.15a1 3653 (Fix handling of opcodes that may leave operands on the stack when optimizing LOAD_FAST)
 
 
     Python 3.16 will start with 3700
@@ -293,7 +294,7 @@ PC/launcher.c must also be updated.
 
 */
 
-#define PYC_MAGIC_NUMBER 3652
+#define PYC_MAGIC_NUMBER 3653
 /* This is equivalent to converting PYC_MAGIC_NUMBER to 2 bytes
    (little-endian) and then appending b'\r\n'. */
 #define PYC_MAGIC_NUMBER_TOKEN \
diff --git a/Include/internal/pycore_object.h b/Include/internal/pycore_object.h
index 3aaee7d0081..50225623fe5 100644
--- a/Include/internal/pycore_object.h
+++ b/Include/internal/pycore_object.h
@@ -313,7 +313,7 @@ extern int _PyDict_CheckConsistency(PyObject *mp, int check_content);
 // Fast inlined version of PyType_HasFeature()
 static inline int
 _PyType_HasFeature(PyTypeObject *type, unsigned long feature) {
-    return ((FT_ATOMIC_LOAD_ULONG_RELAXED(type->tp_flags) & feature) != 0);
+    return ((type->tp_flags) & feature) != 0;
 }
 
 extern void _PyType_InitCache(PyInterpreterState *interp);
@@ -1010,6 +1010,8 @@ enum _PyAnnotateFormat {
     _Py_ANNOTATE_FORMAT_STRING = 4,
 };
 
+int _PyObject_SetDict(PyObject *obj, PyObject *value);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/Include/internal/pycore_stackref.h b/Include/internal/pycore_stackref.h
index f2ecc30b053..87914767252 100644
--- a/Include/internal/pycore_stackref.h
+++ b/Include/internal/pycore_stackref.h
@@ -62,14 +62,15 @@ PyAPI_FUNC(void) _Py_stackref_record_borrow(_PyStackRef ref, const char *filenam
 extern void _Py_stackref_associate(PyInterpreterState *interp, PyObject *obj, _PyStackRef ref);
 
 static const _PyStackRef PyStackRef_NULL = { .index = 0 };
+static const _PyStackRef PyStackRef_ERROR = { .index = 2 };
 
 // Use the first 3 even numbers for None, True and False.
 // Odd numbers are reserved for (tagged) integers
-#define PyStackRef_None ((_PyStackRef){ .index = 2 } )
-#define PyStackRef_False ((_PyStackRef){ .index = 4 })
-#define PyStackRef_True ((_PyStackRef){ .index = 6 })
+#define PyStackRef_None ((_PyStackRef){ .index = 4 } )
+#define PyStackRef_False ((_PyStackRef){ .index = 6 })
+#define PyStackRef_True ((_PyStackRef){ .index = 8 })
 
-#define INITIAL_STACKREF_INDEX 8
+#define INITIAL_STACKREF_INDEX 10
 
 static inline int
 PyStackRef_IsNull(_PyStackRef ref)
@@ -77,6 +78,19 @@ PyStackRef_IsNull(_PyStackRef ref)
     return ref.index == 0;
 }
 
+static inline bool
+PyStackRef_IsError(_PyStackRef ref)
+{
+    return ref.index == 2;
+}
+
+static inline bool
+PyStackRef_IsValid(_PyStackRef ref)
+{
+    /* Invalid values are ERROR and NULL */
+    return !PyStackRef_IsError(ref) && !PyStackRef_IsNull(ref);
+}
+
 static inline int
 PyStackRef_IsTrue(_PyStackRef ref)
 {
@@ -104,6 +118,7 @@ PyStackRef_IsTaggedInt(_PyStackRef ref)
 static inline PyObject *
 _PyStackRef_AsPyObjectBorrow(_PyStackRef ref, const char *filename, int linenumber)
 {
+    assert(!PyStackRef_IsError(ref));
     assert(!PyStackRef_IsTaggedInt(ref));
     _Py_stackref_record_borrow(ref, filename, linenumber);
     return _Py_stackref_get_object(ref);
@@ -155,6 +170,7 @@ _PyStackRef_CLOSE(_PyStackRef ref, const char *filename, int linenumber)
 static inline void
 _PyStackRef_XCLOSE(_PyStackRef ref, const char *filename, int linenumber)
 {
+    assert(!PyStackRef_IsError(ref));
     if (PyStackRef_IsNull(ref)) {
         return;
     }
@@ -165,6 +181,7 @@ _PyStackRef_XCLOSE(_PyStackRef ref, const char *filename, int linenumber)
 static inline _PyStackRef
 _PyStackRef_DUP(_PyStackRef ref, const char *filename, int linenumber)
 {
+    assert(!PyStackRef_IsError(ref));
     if (PyStackRef_IsTaggedInt(ref)) {
         return ref;
     }
@@ -241,9 +258,25 @@ PyStackRef_IsNullOrInt(_PyStackRef ref);
 #else
 
 #define Py_INT_TAG 3
+#define Py_TAG_INVALID 2
 #define Py_TAG_REFCNT 1
 #define Py_TAG_BITS 3
 
+static const _PyStackRef PyStackRef_ERROR = { .bits = Py_TAG_INVALID };
+
+static inline bool
+PyStackRef_IsError(_PyStackRef ref)
+{
+    return ref.bits == Py_TAG_INVALID;
+}
+
+static inline bool
+PyStackRef_IsValid(_PyStackRef ref)
+{
+    /* Invalid values are ERROR and NULL */
+    return ref.bits >= Py_INT_TAG;
+}
+
 static inline bool
 PyStackRef_IsTaggedInt(_PyStackRef i)
 {
@@ -284,6 +317,7 @@ PyStackRef_IncrementTaggedIntNoOverflow(_PyStackRef ref)
 
 
 static const _PyStackRef PyStackRef_NULL = { .bits = Py_TAG_DEFERRED};
+
 #define PyStackRef_IsNull(stackref) ((stackref).bits == PyStackRef_NULL.bits)
 #define PyStackRef_True ((_PyStackRef){.bits = ((uintptr_t)&_Py_TrueStruct) | Py_TAG_DEFERRED })
 #define PyStackRef_False ((_PyStackRef){.bits = ((uintptr_t)&_Py_FalseStruct) | Py_TAG_DEFERRED })
diff --git a/Include/internal/pycore_sysmodule.h b/Include/internal/pycore_sysmodule.h
index 008a2da0d04..347b0a7a790 100644
--- a/Include/internal/pycore_sysmodule.h
+++ b/Include/internal/pycore_sysmodule.h
@@ -8,11 +8,6 @@ extern "C" {
 #  error "this header requires Py_BUILD_CORE define"
 #endif
 
-PyAPI_FUNC(int) _PySys_GetOptionalAttr(PyObject *, PyObject **);
-PyAPI_FUNC(int) _PySys_GetOptionalAttrString(const char *, PyObject **);
-PyAPI_FUNC(PyObject *) _PySys_GetRequiredAttr(PyObject *);
-PyAPI_FUNC(PyObject *) _PySys_GetRequiredAttrString(const char *);
-
 // Export for '_pickle' shared extension
 PyAPI_FUNC(size_t) _PySys_GetSizeOf(PyObject *);
 
diff --git a/Include/internal/pycore_typeobject.h b/Include/internal/pycore_typeobject.h
index 1a4f89fd244..0ee7d555c56 100644
--- a/Include/internal/pycore_typeobject.h
+++ b/Include/internal/pycore_typeobject.h
@@ -134,7 +134,6 @@ extern int _PyType_AddMethod(PyTypeObject *, PyMethodDef *);
 extern void _PyType_SetFlagsRecursive(PyTypeObject *self, unsigned long mask,
                                       unsigned long flags);
 
-extern unsigned int _PyType_GetVersionForCurrentState(PyTypeObject *tp);
 PyAPI_FUNC(void) _PyType_SetVersion(PyTypeObject *tp, unsigned int version);
 PyTypeObject *_PyType_LookupByVersion(unsigned int version);