Merge remote-tracking branch 'upstream/main' into pr/142769

Author: Fidget-Spinner

Include/internal/pycore_opcode_metadata.h

@@ -2631,7 +2631,25 @@ def testfunc(n):
         self.assertNotIn("_POP_TOP_INT", uops)
         self.assertIn("_POP_TOP_NOP", uops)
 
-    def test_store_susbscr_dict(self):
+    def test_store_attr_slot(self):
+        class C:
+            __slots__ = ('x',)
+
+        def testfunc(n):
+            c = C()
+            for _ in range(n):
+                c.x = 42
+                y = c.x
+            return y
+
+        res, ex = self._run_with_optimizer(testfunc, TIER2_THRESHOLD)
+        self.assertEqual(res, 42)
+        self.assertIsNotNone(ex)
+        uops = get_opnames(ex)
+        self.assertIn("_STORE_ATTR_SLOT", uops)
+        self.assertIn("_POP_TOP_NOP", uops)
+
+    def test_store_subscr_dict(self):
         def testfunc(n):
             d = {}
             for _ in range(n):

Include/internal/pycore_uop_ids.h

@@ -18,7 +18,7 @@
 from test.support import (Error, captured_output, cpython_only, ALWAYS_EQ,
                           requires_debug_ranges, has_no_debug_ranges,
                           requires_subprocess)
-from test.support.os_helper import TESTFN, unlink
+from test.support.os_helper import TESTFN, temp_dir, unlink
 from test.support.script_helper import assert_python_ok, assert_python_failure, make_script
 from test.support.import_helper import forget
 from test.support import force_not_colorized, force_not_colorized_test_class
@@ -524,6 +524,33 @@ def __del__(self):
                     b'ZeroDivisionError: division by zero']
         self.assertEqual(stderr.splitlines(), expected)
 
+    @cpython_only
+    def test_lost_io_open(self):
+        # GH-142737: Display the traceback even if io.open is lost
+        crasher = textwrap.dedent("""\
+            import io
+            import traceback
+            # Trigger fallback mode
+            traceback._print_exception_bltin = None
+            del io.open
+            raise RuntimeError("should not crash")
+        """)
+
+        # Create a temporary script to exercise _Py_FindSourceFile
+        with temp_dir() as script_dir:
+            script = make_script(
+                script_dir=script_dir,
+                script_basename='tb_test_no_io_open',
+                source=crasher)
+            rc, stdout, stderr = assert_python_failure(script)
+
+        self.assertEqual(rc, 1)  # Make sure it's not a crash
+
+        expected = [b'Traceback (most recent call last):',
+                    f'  File "{script}", line 6, in <module>'.encode(),
+                    b'RuntimeError: should not crash']
+        self.assertEqual(stderr.splitlines(), expected)
+
     def test_print_exception(self):
         output = StringIO()
         traceback.print_exception(

Include/internal/pycore_uop_metadata.h

@@ -0,0 +1,3 @@
+Tracebacks will be displayed in fallback mode even if :func:`io.open` is lost.
+Previously, this would crash the interpreter.
+Patch by Bartosz Sławecki.

Lib/test/test_capi/test_opt.py

@@ -729,6 +729,7 @@ _Py_COMP_DIAG_POP
 PyObject * _PyObject_CallMethodFormat(PyThreadState *tstate, PyObject *callable,
                                       const char *format, ...)
 {
+    assert(callable != NULL);
     va_list va;
     va_start(va, format);
     PyObject *retval = callmethod(tstate, callable, format, va);

Lib/test/test_traceback.py

@@ -2642,7 +2642,7 @@ dummy_func(
             _GUARD_TYPE_VERSION +
             _STORE_ATTR_WITH_HINT;
 
-        op(_STORE_ATTR_SLOT, (index/1, value, owner --)) {
+        op(_STORE_ATTR_SLOT, (index/1, value, owner -- o)) {
             PyObject *owner_o = PyStackRef_AsPyObjectBorrow(owner);
 
             DEOPT_IF(!LOCK_OBJECT(owner_o));
@@ -2651,14 +2651,16 @@ dummy_func(
             PyObject *old_value = *(PyObject **)addr;
             FT_ATOMIC_STORE_PTR_RELEASE(*(PyObject **)addr, PyStackRef_AsPyObjectSteal(value));
             UNLOCK_OBJECT(owner_o);
-            PyStackRef_CLOSE(owner);
+            INPUTS_DEAD();
+            o = owner;
             Py_XDECREF(old_value);
         }
 
         macro(STORE_ATTR_SLOT) =
             unused/1 +
             _GUARD_TYPE_VERSION +
-            _STORE_ATTR_SLOT;
+            _STORE_ATTR_SLOT +
+            POP_TOP;
 
         family(COMPARE_OP, INLINE_CACHE_ENTRIES_COMPARE_OP) = {
             COMPARE_OP_FLOAT,