#!/usr/bin/env python3
"""Compile update_arg's exact keys branch as C89; check evaluation/cleanup order."""

import re
import subprocess
import sys
import tempfile
from pathlib import Path

source = Path(sys.argv[1]).read_text()
function = source.split("mutablemapping_update_arg(PyObject *self, PyObject *arg)\n{", 1)[1]
match = re.search(
    r"    if \(func != NULL\) \{.*?(?=    if \(_PyObject_LookupAttr\(arg, &_Py_ID\(items\))",
    function, re.S,
)
assert match, "update_arg keys branch not found"
harness = r'''
#include <assert.h>
#include <stddef.h>
#include <string.h>
typedef struct { int unused; } PyObject;
static PyObject self_obj, arg_obj, func_obj, keys_obj, iter_obj, key_obj, value_obj;
static int scenario, calls, error;
static char events[64];
static void event(char c) {
    size_t n = strlen(events);
    assert(n + 1 < sizeof(events));
    events[n] = c;
    events[n + 1] = '\0';
}
static PyObject * _PyObject_CallNoArgs(PyObject *obj) {
    assert(obj == &func_obj); event('C');
    return scenario == 0 ? NULL : &keys_obj;
}
static void Py_DECREF(PyObject *obj) {
    if (obj == &func_obj) event('f');
    else if (obj == &keys_obj) event('k');
    else if (obj == &iter_obj) event('i');
    else if (obj == &key_obj) event('q');
    else { assert(obj == &value_obj); event('v'); }
}
static PyObject *PyObject_GetIter(PyObject *obj) {
    assert(obj == &keys_obj); event('I');
    return scenario == 1 ? NULL : &iter_obj;
}
static PyObject *PyIter_Next(PyObject *obj) {
    assert(obj == &iter_obj); event('N');
    if (scenario == 2 || scenario == 3 || calls++ > 0) {
        error = scenario == 3 || scenario == 7;
        return NULL;
    }
    return &key_obj;
}
static PyObject *PyObject_GetItem(PyObject *obj, PyObject *key) {
    assert(obj == &arg_obj && key == &key_obj); event('G');
    return scenario == 4 ? NULL : &value_obj;
}
static int PyObject_SetItem(PyObject *obj, PyObject *key, PyObject *value) {
    assert(obj == &self_obj && key == &key_obj && value == &value_obj);
    event('S'); return scenario == 5 ? -1 : 0;
}
static int PyErr_Occurred(void) { event('E'); return error; }
static int run(PyObject *self, PyObject *arg, PyObject *func) {
    int res = 0;
'''
harness += match.group(0)
harness += r'''
    return 42;
}
int main(void) {
    static const char *expected[] = {
        "Cf", "CfIk", "CfIkNiE", "CfIkNiE",
        "CfIkNGqi", "CfIkNGSvqi", "CfIkNGSvqNiE", "CfIkNGSvqNiE"
    };
    int result;
    for (scenario = 0; scenario < 8; ++scenario) {
        events[0] = '\0'; calls = error = 0;
        result = run(&self_obj, &arg_obj, &func_obj);
        assert(result == (scenario == 2 || scenario == 6 ? 0 : -1));
        assert(strcmp(events, expected[scenario]) == 0);
    }
    return 0;
}
'''
with tempfile.TemporaryDirectory(prefix="vc6-odict-update-arg-iterator-") as directory:
    path = Path(directory)
    (path / "test.c").write_text(harness)
    result = subprocess.run([
        "cc", "-std=c89", "-pedantic-errors", "-Wall", "-Wextra", "-Werror",
        str(path / "test.c"), "-o", str(path / "test"),
    ])
    if result.returncode:
        sys.exit(result.returncode)
    subprocess.run([str(path / "test")], check=True)
print("update_arg keys branch C89 compile and evaluation/cleanup order: PASS (8 cases)")