#!/usr/bin/env python3
"""Compile the exact set types as C89 and verify every static slot."""

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

source_path = Path(sys.argv[1])
source = source_path.read_text()
initializers = {}
for name in ("PySet_Type", "PyFrozenSet_Type"):
    match = re.search(r"PyTypeObject " + name + r" = \{.*?\n\};", source, re.S)
    assert match, name + " initializer not found"
    initializers[name] = match.group(0)
header = (source_path.parent.parent / "Include/cpython/object.h").read_text()
layout = re.search(r"struct _typeobject \{(.*?)\n\};", header, re.S)
assert layout, "PyTypeObject layout not found"
body = re.sub(r"/\*.*?\*/|//[^\n]*", "", layout.group(1), flags=re.S)
fields = re.findall(r"\b(tp_\w+)\b", body)
assert len(fields) == len(set(fields)) == 48, "review changed PyTypeObject layout"
expected = {
    "tp_basicsize": "sizeof(PySetObject)",
    "tp_dealloc": "(destructor)set_dealloc",
    "tp_repr": "(reprfunc)set_repr",
    "tp_as_sequence": "&set_as_sequence",
    "tp_getattro": "PyObject_GenericGetAttr",
    "tp_flags": "Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC | Py_TPFLAGS_BASETYPE | _Py_TPFLAGS_MATCH_SELF",
    "tp_traverse": "(traverseproc)set_traverse",
    "tp_clear": "(inquiry)set_clear_internal",
    "tp_richcompare": "(richcmpfunc)set_richcompare",
    "tp_weaklistoffset": "offsetof(PySetObject, weakreflist)",
    "tp_iter": "(getiterfunc)set_iter",
    "tp_alloc": "PyType_GenericAlloc",
    "tp_free": "PyObject_GC_Del",
}
assert expected.keys() <= set(fields)
# Use the real field declarations/order, with minimal stand-ins for dependencies.
harness = r'''
#include <assert.h>
#include <stddef.h>
#include <string.h>
typedef long Py_ssize_t;
typedef struct { int unused; } PyObject;
typedef struct { int unused; } PyAsyncMethods;
typedef struct { int unused; } PyNumberMethods;
typedef struct { int unused; } PySequenceMethods;
typedef struct { int unused; } PyMappingMethods;
typedef struct { int unused; } PyBufferProcs;
typedef struct { int unused; } PyMethodDef;
typedef struct { int unused; } PyMemberDef;
typedef struct { int unused; } PyGetSetDef;
typedef struct _typeobject PyTypeObject;
typedef struct { long head; PyObject *weakreflist; } PySetObject;
#define PyObject_VAR_HEAD long ob_refcnt; PyTypeObject *ob_type; long ob_size;
#define PyVarObject_HEAD_INIT(type, size) 1, type, size,
#define Py_TPFLAGS_DEFAULT 1UL
#define Py_TPFLAGS_HAVE_GC 2UL
#define Py_TPFLAGS_BASETYPE 4UL
#define _Py_TPFLAGS_MATCH_SELF 8UL
'''
for name in (
    "destructor getattrfunc setattrfunc reprfunc hashfunc ternaryfunc "
    "getattrofunc setattrofunc traverseproc inquiry richcmpfunc getiterfunc "
    "iternextfunc descrgetfunc descrsetfunc initproc allocfunc newfunc "
    "freefunc vectorcallfunc"
).split():
    harness += f"typedef void (*{name})(void);\n"
harness += "struct _typeobject {" + body + "};\n"
for name in (
    "set_new frozenset_new set_dealloc set_repr PyObject_HashNotImplemented "
    "frozenset_hash PyObject_GenericGetAttr set_traverse set_clear_internal "
    "set_richcompare set_iter set_init PyType_GenericAlloc PyObject_GC_Del "
    "set_vectorcall frozenset_vectorcall"
).split():
    harness += f"static void {name}(void) {{ }}\n"
harness += "static PyTypeObject PyType_Type;\n"
harness += "static PySequenceMethods set_as_sequence;\n"
for prefix in ("set", "frozenset"):
    harness += f"static PyNumberMethods {prefix}_as_number;\n"
    harness += f"static PyMethodDef {prefix}_methods[1];\n"
    harness += f'static const char {prefix}_doc[] = "{prefix} documentation";\n'
harness += "\n".join(initializers.values()) + "\nint main(void)\n{\n"
for name, prefix in (("PySet_Type", "set"), ("PyFrozenSet_Type", "frozenset")):
    values = dict(expected, tp_name=f'"{prefix}"',
                  tp_as_number=f"&{prefix}_as_number", tp_doc=f"{prefix}_doc",
                  tp_methods=f"{prefix}_methods", tp_new=f"{prefix}_new",
                  tp_vectorcall=f"{prefix}_vectorcall",
                  tp_hash="PyObject_HashNotImplemented" if prefix == "set" else "frozenset_hash",
                  tp_init="(initproc)set_init" if prefix == "set" else "0")
    assert values.keys() <= set(fields)
    harness += f"    assert({name}.ob_refcnt == 1);\n"
    harness += f"    assert({name}.ob_type == &PyType_Type);\n"
    harness += f"    assert({name}.ob_size == 0);\n"
    for field in fields:
        value = values.get(field, "0")
        if field in ("tp_name", "tp_doc"):
            harness += f"    assert(strcmp({name}.{field}, {value}) == 0);\n"
        else:
            harness += f"    assert({name}.{field} == ({value}));\n"
harness += "    return 0;\n}\n"
with tempfile.TemporaryDirectory(prefix="vc6-setobject-type-vectorcall-") 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("PySet_Type and PyFrozenSet_Type C89 compile and all 48 semantic field mappings each: PASS")