port: advance VC6 typeobject frontier and preserve regression coverage

2026-10-26 18:09:33 +00:00
parent 35caf1a558
commit 5ab291a68c
162 changed files with 15675 additions and 85 deletions
@@ -0,0 +1,54 @@
+#!/usr/bin/env python3
+"""Check tupledealloc's C89 declaration and exact teardown evaluation order."""
+import re
+import sys
+from pathlib import Path
+
+source = Path(sys.argv[1] if len(sys.argv) > 1 else "cpython/Objects/tupleobject.c")
+match = re.search(
+    r"static void\ntupledealloc\(PyTupleObject \*op\)\n\{(.*?)\n\}",
+    source.read_text(),
+    re.S,
+)
+assert match, "tupledealloc definition not found"
+body = match.group(1)
+assert re.match(r"\s*Py_ssize_t i;", body), (
+    "tupledealloc: i must be declared without initializer before the empty "
+    "tuple check; declaration after Py_TRASHCAN_BEGIN is not C89 compatible"
+)
+expected = """
+    Py_ssize_t i;
+    if (Py_SIZE(op) == 0) {
+        /* The empty tuple is statically allocated. */
+        if (op == &_Py_SINGLETON(tuple_empty)) {
+#ifdef Py_DEBUG
+            _Py_FatalRefcountError("deallocating the empty tuple singleton");
+#else
+            return;
+#endif
+        }
+#ifdef Py_DEBUG
+        /* tuple subclasses have their own empty instances. */
+        assert(!PyTuple_CheckExact(op));
+#endif
+    }
+
+    PyObject_GC_UnTrack(op);
+    Py_TRASHCAN_BEGIN(op, tupledealloc)
+
+    i = Py_SIZE(op);
+    while (--i >= 0) {
+        Py_XDECREF(op->ob_item[i]);
+    }
+    // This will abort on the empty singleton (if there is one).
+    if (!maybe_freelist_push(op)) {
+        Py_TYPE(op)->tp_free((PyObject *)op);
+    }
+
+    Py_TRASHCAN_END
+"""
+assert re.sub(r"\s+", "", body) == re.sub(r"\s+", "", expected), (
+    "preserve empty-tuple guards, GC untracking, size assignment immediately "
+    "after trashcan entry, reverse item decrefs, freelist/free, and trashcan exit"
+)
+print("tupledealloc C89 declaration and exact teardown evaluation order: PASS")