port: expand VC6 C89 core frontier

2026-10-03 17:47:57 +00:00
parent 9221a2ee0e
commit 35caf1a558
15 changed files with 5972 additions and 11 deletions
@@ -0,0 +1,98 @@
+#!/usr/bin/env python3
+"""Guard C89 declaration placement and reference order in iterobject.c."""
+import sys
+from pathlib import Path
+from typing import NoReturn
+
+
+def fail(message: str) -> NoReturn:
+    print(message, file=sys.stderr)
+    raise SystemExit(1)
+
+
+def extract_function(source: str, signature: str) -> str:
+    start = source.find(signature)
+    if start < 0:
+        fail(f"missing function signature: {signature}")
+    brace = source.find("{", start + len(signature))
+    if brace < 0:
+        fail("missing function body")
+    depth = 0
+    for end in range(brace, len(source)):
+        if source[end] == "{":
+            depth += 1
+        elif source[end] == "}":
+            depth -= 1
+            if depth == 0:
+                return source[brace + 1:end]
+    fail("unterminated function body")
+
+
+def ordered(body: str, tokens: tuple[str, ...], message: str) -> None:
+    positions = [body.find(token) for token in tokens]
+    if any(position < 0 for position in positions) or positions != sorted(positions):
+        fail(message)
+
+
+source = Path(sys.argv[1]).read_text(encoding="utf-8")
+
+getiter = extract_function(source, "anextawaitable_getiter(anextawaitableobject *obj)")
+for declaration in ("PyObject *awaitable;", "unaryfunc getter;", "PyObject *new_awaitable;"):
+    if declaration not in getiter:
+        fail("anextawaitable_getiter local must be declared before use: " + declaration)
+for late in ("PyObject *awaitable =", "unaryfunc getter =", "PyObject *new_awaitable ="):
+    if late in getiter:
+        fail("anextawaitable_getiter must not initialize a local in a late declaration: " + late)
+branch = getiter.split("if (Py_TYPE(awaitable)->tp_iternext == NULL) {", 1)[1]
+if branch.find("unaryfunc getter;") > branch.find("getter = Py_TYPE(awaitable)->tp_as_async->am_await;"):
+    fail("anextawaitable_getiter branch locals must be declared before statements")
+if branch.find("PyObject *new_awaitable;") > branch.find("getter = Py_TYPE(awaitable)->tp_as_async->am_await;"):
+    fail("anextawaitable_getiter branch locals must be declared before statements")
+ordered(getiter, (
+    "assert(obj->wrapped != NULL);",
+    "awaitable = _PyCoro_GetAwaitableIter(obj->wrapped);",
+    "if (awaitable == NULL)",
+    "if (Py_TYPE(awaitable)->tp_iternext == NULL)",
+    "getter = Py_TYPE(awaitable)->tp_as_async->am_await;",
+    "new_awaitable = getter(awaitable);",
+    "if (new_awaitable == NULL)",
+    "Py_SETREF(awaitable, new_awaitable);",
+    "if (!PyIter_Check(awaitable))",
+    "return awaitable;",
+), "anextawaitable_getiter must preserve awaitable conversion and cleanup order")
+
+iternext = extract_function(source, "anextawaitable_iternext(anextawaitableobject *obj)")
+for declaration in ("PyObject *awaitable;", "PyObject *result;"):
+    if declaration not in iternext:
+        fail("anextawaitable_iternext local must be declared at function entry: " + declaration)
+if "PyObject *result =" in iternext:
+    fail("anextawaitable_iternext result must not be declared after the NULL guard")
+ordered(iternext, (
+    "awaitable = anextawaitable_getiter(obj);",
+    "if (awaitable == NULL)",
+    "result = (*Py_TYPE(awaitable)->tp_iternext)(awaitable);",
+    "Py_DECREF(awaitable);",
+    "if (result != NULL)",
+    "if (PyErr_ExceptionMatches(PyExc_StopAsyncIteration))",
+    "_PyGen_SetStopIterationValue(obj->default_value);",
+    "\n    return NULL;",
+), "anextawaitable_iternext must preserve call, decref, and StopAsyncIteration handling order")
+
+proxy = extract_function(source, "anextawaitable_proxy(anextawaitableobject *obj, char *meth, PyObject *arg)")
+for declaration in ("PyObject *awaitable;", "PyObject *ret;"):
+    if declaration not in proxy:
+        fail("anextawaitable_proxy local must be declared at function entry: " + declaration)
+if "PyObject *ret =" in proxy:
+    fail("anextawaitable_proxy result must not be declared after the NULL guard")
+ordered(proxy, (
+    "awaitable = anextawaitable_getiter(obj);",
+    "if (awaitable == NULL)",
+    "ret = PyObject_CallMethod(awaitable, meth, \"O\", arg);",
+    "Py_DECREF(awaitable);",
+    "if (ret != NULL)",
+    "if (PyErr_ExceptionMatches(PyExc_StopAsyncIteration))",
+    "_PyGen_SetStopIterationValue(obj->default_value);",
+    "\n    return NULL;",
+), "anextawaitable_proxy must preserve call, decref, and exception handling order")
+
+print("iterobject anextawaitable C89 declarations and reference order: PASS")