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 +1,132 @@
+#!/usr/bin/env python3
+"""Focused Visual C++ 6.0 C89 regression checks for methodobject.c."""
+
+import re
+import sys
+from pathlib import Path
+
+source = Path(sys.argv[1]).read_text()
+
+match = re.search(
+    r"PyObject \*\s*PyCMethod_New\(PyMethodDef \*ml, PyObject \*self, PyObject \*module, PyTypeObject \*cls\)\s*\{(?P<body>.*?)\n\}",
+    source,
+    re.S,
+)
+assert match, "PyCMethod_New definition not found"
+body = match.group("body")
+declarations = ("vectorcallfunc vectorcall;", "PyCFunctionObject *op;", "PyCMethodObject *om;", "switch (ml->ml_flags")
+declaration_positions = [body.find(token) for token in declarations]
+assert all(position >= 0 for position in declaration_positions) and declaration_positions == sorted(declaration_positions), (
+    "PyCMethod_New must declare op and om at function entry before its dispatch switch"
+)
+ordered = (
+    "switch (ml->ml_flags",
+    "op = NULL;",
+    "if (ml->ml_flags & METH_METHOD)",
+    "om = PyObject_GC_New(PyCMethodObject, &PyCMethod_Type);",
+    "op = PyObject_GC_New(PyCFunctionObject, &PyCFunction_Type);",
+    "op->m_weakreflist = NULL;",
+)
+positions = [body.find(token) for token in ordered]
+assert all(position >= 0 for position in positions) and positions == sorted(positions), (
+    "PyCMethod_New must preserve flag dispatch, null initialization, allocation, and field setup order"
+)
+assert "PyCFunctionObject *op =" not in body and "PyCMethodObject *om =" not in body, (
+    "PyCMethod_New must not introduce late C89 declarations"
+)
+print("methodobject PyCMethod_New C89 declarations and allocation order: PASS")
+
+match = re.search(r"PyTypeObject PyCMethod_Type = \{(?P<body>.*?)\n\};", source, re.S)
+assert match, "PyCMethod_Type initializer not found"
+body = match.group("body")
+assert ".tp_" not in body, "PyCMethod_Type must use positional fields instead of C99 designated initializers"
+expected = (
+    "PyVarObject_HEAD_INIT(&PyType_Type, 0)",
+    '"builtin_method"',
+    "sizeof(PyCMethodObject)",
+) + ("0,",) * 27 + ("&PyCFunction_Type",)
+positions = []
+cursor = 0
+for token in expected:
+    position = body.find(token, cursor)
+    positions.append(position)
+    if position >= 0:
+        cursor = position + len(token)
+assert all(position >= 0 for position in positions), "PyCMethod_Type positional initializer must preserve the base-type slot"
+print("methodobject PyCMethod_Type C89 positional initializer: PASS")
+
+
+def function_body(name):
+    found = re.search(
+        r"static PyObject \*\s*" + re.escape(name) + r"\s*\([^;]*\)\s*\{(?P<body>.*?)\n\}",
+        source,
+        re.S,
+    )
+    assert found, name + " definition not found"
+    return found.group("body")
+
+
+checks = {
+    "cfunction_vectorcall_FASTCALL": (
+        "PyThreadState *tstate;",
+        "Py_ssize_t nargs;",
+        "_PyCFunctionFast meth;",
+        "PyObject *result;",
+        "tstate = _PyThreadState_GET();",
+        "nargs = PyVectorcall_NARGS(nargsf);",
+        "meth = (_PyCFunctionFast)",
+        "result = meth(",
+    ),
+    "cfunction_vectorcall_FASTCALL_KEYWORDS": (
+        "PyThreadState *tstate;",
+        "Py_ssize_t nargs;",
+        "_PyCFunctionFastWithKeywords meth;",
+        "PyObject *result;",
+        "tstate = _PyThreadState_GET();",
+        "nargs = PyVectorcall_NARGS(nargsf);",
+        "meth = (_PyCFunctionFastWithKeywords)",
+        "result = meth(",
+    ),
+    "cfunction_vectorcall_NOARGS": (
+        "Py_ssize_t nargs;",
+        "PyCFunction meth;",
+        "PyObject *result;",
+        "PyThreadState *tstate = _PyThreadState_GET();",
+        "if (cfunction_check_kwargs(",
+        "nargs = PyVectorcall_NARGS(nargsf);",
+        "meth = (PyCFunction)cfunction_enter_call(",
+        "result = _PyCFunction_TrampolineCall(",
+    ),
+    "cfunction_vectorcall_O": (
+        "Py_ssize_t nargs;",
+        "PyCFunction meth;",
+        "PyObject *result;",
+        "PyThreadState *tstate = _PyThreadState_GET();",
+        "if (cfunction_check_kwargs(",
+        "nargs = PyVectorcall_NARGS(nargsf);",
+        "meth = (PyCFunction)cfunction_enter_call(",
+        "result = _PyCFunction_TrampolineCall(",
+    ),
+    "cfunction_call": (
+        "PyThreadState *tstate;",
+        "int flags;",
+        "PyCFunction meth;",
+        "PyObject *self;",
+        "PyObject *result;",
+        "assert(kwargs == NULL || PyDict_Check(kwargs));",
+        "tstate = _PyThreadState_GET();",
+        "flags = PyCFunction_GET_FLAGS(func);",
+        "meth = PyCFunction_GET_FUNCTION(func);",
+        "self = PyCFunction_GET_SELF(func);",
+    ),
+}
+for name, tokens in checks.items():
+    body = function_body(name)
+    positions = [body.find(token) for token in tokens]
+    assert all(position >= 0 for position in positions) and positions == sorted(positions), (
+        name + " must keep declarations before statements and preserve evaluation order"
+    )
+    for declaration in tokens[:5]:
+        if " = " not in declaration and declaration.endswith(";"):
+            assert declaration in body, name + " is missing an opening local declaration"
+print("methodobject vectorcall and call paths C89 declarations and evaluation order: PASS")