/src/cpython/Python/slots.c

Source
/* Common handling of type/module slots
 */

#include "Python.h"

#include "pycore_slots.h"

#include <stdio.h>

// Iterating through a recursive structure doesn't look great in a debugger.
// Flip the #if to 1 to get a trace on stderr.
// (The messages can also serve as code comments.)
#if 0
#define MSG(...) { \
    fprintf(stderr, "slotiter: " __VA_ARGS__); fprintf(stderr, "\n");}
#else
#define MSG(...)
#endif

static char*
kind_name(_PySlot_KIND kind)
{
    switch (kind) {
        case _PySlot_KIND_TYPE: return "type";
        case _PySlot_KIND_MOD: return "module";
        case _PySlot_KIND_COMPAT: return "compat";
        case _PySlot_KIND_SLOT: return "generic slot";
    }
    Py_UNREACHABLE();
}

static void
init_with_kind(_PySlotIterator *it, const void *slots,
               _PySlot_KIND result_kind,
               _PySlot_KIND slot_struct_kind)
{
    MSG("");
    MSG("init (%s slot iterator)", kind_name(result_kind));
    it->state = it->states;
    it->state->any_slot = slots;
    it->state->slot_struct_kind = slot_struct_kind;
    it->kind = result_kind;
    it->name = NULL;
    it->recursion_level = 0;
    it->is_at_end = false;
    it->is_first_run = true;
    it->current.sl_id = 0;
    memset(it->seen, 0, sizeof(it->seen));
}

void
_PySlotIterator_Init(_PySlotIterator *it, const PySlot *slots,
                     _PySlot_KIND result_kind)
{
    init_with_kind(it, slots, result_kind, _PySlot_KIND_SLOT);
}

void
_PySlotIterator_InitLegacy(_PySlotIterator *it, const void *slots,
                           _PySlot_KIND kind)
{
    init_with_kind(it, slots, kind, kind);
}

void
_PySlotIterator_Rewind(_PySlotIterator *it, const void *slots)
{
    MSG("");
    MSG("rewind (%s slot iterator)", kind_name(it->kind));
    assert (it->is_at_end);
    assert (it->recursion_level == 0);
    assert (it->state == it->states);
    it->is_at_end = false;
    it->state->any_slot = slots;
    it->is_first_run = false;
}

static Py_ssize_t
seen_index(uint16_t id)
{
    return id / _PySlot_SEEN_ENTRY_BITS;
}

static unsigned int
seen_mask(uint16_t id)
{
    return ((unsigned int)1) << (id % _PySlot_SEEN_ENTRY_BITS);
}

bool
_PySlotIterator_SawSlot(_PySlotIterator *it, int id)
{
    assert (id > 0);
    assert (id < _Py_slot_COUNT);
    return it->seen[seen_index(id)] & seen_mask(id);
}

// Advance `it` to the next entry. Currently cannot fail.
static void
advance(_PySlotIterator *it)
{
    MSG("advance (at level %d)", (int)it->recursion_level);
    switch (it->state->slot_struct_kind) {
        case _PySlot_KIND_SLOT: it->state->slot++; break;
        case _PySlot_KIND_TYPE: it->state->tp_slot++; break;
        case _PySlot_KIND_MOD: it->state->mod_slot++; break;
        default:
            Py_UNREACHABLE();
    }
}

static int handle_first_run(_PySlotIterator *it);

bool
_PySlotIterator_Next(_PySlotIterator *it)
{
    MSG("next");
    assert(it);
    assert(!it->is_at_end);
    assert(!PyErr_Occurred());

    it->current.sl_id = -1;

    while (true) {
        if (it->state->slot == NULL) {
            if (it->recursion_level == 0) {
                MSG("end (initial nesting level done)");
                it->is_at_end = true;
                return 0;
            }
            MSG("pop nesting level %d", (int)it->recursion_level);
            it->recursion_level--;
            it->state = &it->states[it->recursion_level];
            advance(it);
            continue;
        }

        switch (it->state->slot_struct_kind) {
            case _PySlot_KIND_SLOT: {
                MSG("copying PySlot structure");
                it->current = *it->state->slot;
            } break;
            case _PySlot_KIND_TYPE: {
                MSG("converting PyType_Slot structure");
                memset(&it->current, 0, sizeof(it->current));
                it->current.sl_id = (uint16_t)it->state->tp_slot->slot;
                it->current.sl_flags = PySlot_INTPTR;
                it->current.sl_ptr = (void*)it->state->tp_slot->pfunc;
            } break;
            case _PySlot_KIND_MOD: {
                MSG("converting PyModuleDef_Slot structure");
                memset(&it->current, 0, sizeof(it->current));
                it->current.sl_id = (uint16_t)it->state->mod_slot->slot;
                it->current.sl_flags = PySlot_INTPTR;
                it->current.sl_ptr = (void*)it->state->mod_slot->value;
            } break;
            default: {
                Py_UNREACHABLE();
            } break;
        }

        /* shorter local names */
        PySlot *const result = &it->current;
        uint16_t flags = result->sl_flags;

        MSG("slot %d, flags 0x%x, from %p",
            (int)result->sl_id, (unsigned)flags, it->state->slot);

        uint16_t orig_id = result->sl_id;
        switch (it->kind) {
            case _PySlot_KIND_TYPE:
                result->sl_id = _PySlot_resolve_type_slot(result->sl_id);
                break;
            case _PySlot_KIND_MOD:
                result->sl_id = _PySlot_resolve_mod_slot(result->sl_id);
                break;
            default:
                Py_UNREACHABLE();
        }
        MSG("resolved to slot %d (%s)",
            (int)result->sl_id, _PySlot_GetName(result->sl_id));

        if (result->sl_id == Py_slot_invalid) {
            MSG("error (unknown/invalid slot)");
            if (flags & PySlot_OPTIONAL) {
                advance(it);
                continue;
            }
            _PySlot_err_bad_slot(kind_name(it->kind), orig_id);
            goto error;
        }
        if (result->sl_id == Py_slot_end) {
            MSG("sentinel slot, flags %x", (unsigned)flags);
            if (flags & PySlot_OPTIONAL) {
                MSG("error (bad flags on sentinel)");
                PyErr_Format(PyExc_SystemError,
                            "invalid flags for Py_slot_end: 0x%x",
                             (unsigned int)flags);
                goto error;
            }
            it->state->slot = NULL;
            continue;
        }

        if (result->sl_id == Py_slot_subslots
            || result->sl_id == Py_tp_slots
            || result->sl_id == Py_mod_slots
        ) {
            if (result->sl_ptr == NULL) {
                MSG("NULL subslots; skipping");
                advance(it);
                continue;
            }
            if ((it->states[0].slot_struct_kind == _PySlot_KIND_MOD)
                && (it->state->slot_struct_kind == _PySlot_KIND_SLOT)
                && !(result->sl_flags & PySlot_STATIC))
            {
                PyErr_Format(PyExc_SystemError,
                             "slots included from PyModuleDef must be static");
                goto error;
            }
            it->recursion_level++;
            MSG("recursing into level %d", it->recursion_level);
            if (it->recursion_level >= _PySlot_MAX_NESTING) {
                MSG("error (too much nesting)");
                PyErr_Format(PyExc_SystemError,
                            "%s (slot %d): too many levels of nested slots",
                            _PySlot_GetName(result->sl_id), orig_id);
                goto error;
            }
            it->state = &it->states[it->recursion_level];
            memset(it->state, 0, sizeof(_PySlotIterator_state));
            it->state->slot = result->sl_ptr;
            switch (result->sl_id) {
                case Py_slot_subslots:
                    it->state->slot_struct_kind = _PySlot_KIND_SLOT; break;
                case Py_tp_slots:
                    it->state->slot_struct_kind = _PySlot_KIND_TYPE; break;
                case Py_mod_slots:
                    it->state->slot_struct_kind = _PySlot_KIND_MOD; break;
            }
            continue;
        }

        if (flags & PySlot_INTPTR) {
            MSG("casting from intptr");
            /* this should compile to nothing on common architectures */
            switch (_PySlot_get_dtype(result->sl_id)) {
                case _PySlot_DTYPE_SIZE: {
                    result->sl_size = (Py_ssize_t)(intptr_t)result->sl_ptr;
                } break;
                case _PySlot_DTYPE_INT64: {
                    result->sl_int64 = (int64_t)(intptr_t)result->sl_ptr;
                } break;
                case _PySlot_DTYPE_UINT64: {
                    result->sl_uint64 = (uint64_t)(intptr_t)result->sl_ptr;
                } break;
                case _PySlot_DTYPE_PTR:
                case _PySlot_DTYPE_FUNC:
                case _PySlot_DTYPE_VOID:
                    break;
            }
        }

        advance(it);
        switch (_PySlot_get_dtype(result->sl_id)) {
            case _PySlot_DTYPE_VOID:
            case _PySlot_DTYPE_PTR:
                MSG("result: %d (%s): %p",
                    (int)result->sl_id, _PySlot_GetName(result->sl_id),
                    (void*)result->sl_ptr);
                break;
            case _PySlot_DTYPE_FUNC:
                MSG("result: %d (%s): %p",
                    (int)result->sl_id, _PySlot_GetName(result->sl_id),
                    (void*)result->sl_func);
                break;
            case _PySlot_DTYPE_SIZE:
                MSG("result: %d (%s): %zd",
                    (int)result->sl_id, _PySlot_GetName(result->sl_id),
                    (Py_ssize_t)result->sl_size);
                break;
            case _PySlot_DTYPE_INT64:
                MSG("result: %d (%s): %ld",
                    (int)result->sl_id,  _PySlot_GetName(result->sl_id),
                    (long)result->sl_int64);
                break;
            case _PySlot_DTYPE_UINT64:
                MSG("result: %d (%s): %lu (0x%lx)",
                    (int)result->sl_id, _PySlot_GetName(result->sl_id),
                    (unsigned long)result->sl_int64,
                    (unsigned long)result->sl_int64);
                break;
        }
        assert (result->sl_id > 0);
        assert (result->sl_id <= _Py_slot_COUNT);
        if (it->is_first_run && (handle_first_run(it) < 0)) {
            goto error;
        }
        return result->sl_id != Py_slot_end;
    }
    Py_UNREACHABLE();

error:
    it->current.sl_id = Py_slot_invalid;
    return true;
}

/* Validate current slot, and do bookkeeping */
static int
handle_first_run(_PySlotIterator *it)
{
    int id = it->current.sl_id;

    if (_PySlot_get_must_be_static(id)) {
        if (!(it->current.sl_flags & PySlot_STATIC)
            && (it->state->slot_struct_kind == _PySlot_KIND_SLOT))
        {
            PyErr_Format(
                PyExc_SystemError,
                "%s requires PySlot_STATIC",
                _PySlot_GetName(id));
            return -1;
        }
    }

    _PySlot_PROBLEM_HANDLING null_handling = _PySlot_get_null_handling(id);
    if (null_handling != _PySlot_PROBLEM_ALLOW) {
        bool is_null = false;
        switch (_PySlot_get_dtype(id)) {
            case _PySlot_DTYPE_PTR: {
                is_null = it->current.sl_ptr == NULL;
            } break;
            case _PySlot_DTYPE_FUNC: {
                is_null = it->current.sl_func == NULL;
            } break;
            default: {
                //Py_UNREACHABLE();
            } break;
        }
        if (is_null) {
            MSG("slot is NULL but shouldn't");
            if (null_handling == _PySlot_PROBLEM_REJECT) {
                MSG("error (NULL rejected)");
                PyErr_Format(PyExc_SystemError,
                             "NULL not allowed for slot %s",
                             _PySlot_GetName(id));
                return -1;
            }
            if (it->states[0].slot_struct_kind == _PySlot_KIND_SLOT) {
                MSG("deprecated NULL");
                if (PyErr_WarnFormat(
                    PyExc_DeprecationWarning,
                    1,
                    "NULL value in slot %s is deprecated",
                    _PySlot_GetName(id)) < 0)
                {
                    return -1;
                }
            }
            else {
                MSG("unwanted NULL in legacy struct");
            }
        }
    }

    _PySlot_PROBLEM_HANDLING duplicate_handling = _PySlot_get_duplicate_handling(id);
    if (duplicate_handling != _PySlot_PROBLEM_ALLOW) {
        if (_PySlotIterator_SawSlot(it, id)) {
            MSG("slot was seen before but shouldn't be duplicated");
            if (duplicate_handling == _PySlot_PROBLEM_REJECT) {
                MSG("error (duplicate rejected)");
                PyErr_Format(
                    PyExc_SystemError,
                    "%s%s%s has multiple %s (%d) slots",
                    kind_name(it->kind),
                    it->name ? " " : "",
                    it->name ? it->name : "",
                    _PySlot_GetName(id),
                    (int)it->current.sl_id);
                return -1;
            }
            if (it->states[0].slot_struct_kind == _PySlot_KIND_SLOT) {
                MSG("deprecated duplicate");
                if (PyErr_WarnFormat(
                        PyExc_DeprecationWarning,
                        0,
                        "%s%s%s has multiple %s (%d) slots. This is deprecated.",
                        kind_name(it->kind),
                        it->name ? " " : "",
                        it->name ? it->name : "",
                        _PySlot_GetName(id),
                        (int)it->current.sl_id) < 0) {
                    return -1;
                }
            }
            else {
                MSG("unwanted duplicate in legacy struct");
            }
        }
    }
    it->seen[seen_index(id)] |= seen_mask(id);
    return 0;
}

Coverage Report

Created: 2026-05-30 06:18

Line	Count	Source
1		/* Common handling of type/module slots
2		*/
3
4		#include "Python.h"
5
6		#include "pycore_slots.h"
7
8		#include <stdio.h>
9
10		// Iterating through a recursive structure doesn't look great in a debugger.
11		// Flip the #if to 1 to get a trace on stderr.
12		// (The messages can also serve as code comments.)
13		#if 0
14		#define MSG(...) { \
15		fprintf(stderr, "slotiter: " __VA_ARGS__); fprintf(stderr, "\n");}
16		#else
17		#define MSG(...)
18		#endif
19
20		static char*
21		kind_name(_PySlot_KIND kind)
22	0	{
23	0	switch (kind) {
24	0	case _PySlot_KIND_TYPE: return "type";
25	0	case _PySlot_KIND_MOD: return "module";
26	0	case _PySlot_KIND_COMPAT: return "compat";
27	0	case _PySlot_KIND_SLOT: return "generic slot";
28	0	}
29	0	Py_UNREACHABLE();
30	0	}
31
32		static void
33		init_with_kind(_PySlotIterator it, const void slots,
34		_PySlot_KIND result_kind,
35		_PySlot_KIND slot_struct_kind)
36	4.95k	{
37	4.95k	MSG("");
38	4.95k	MSG("init (%s slot iterator)", kind_name(result_kind));
39	4.95k	it->state = it->states;
40	4.95k	it->state->any_slot = slots;
41	4.95k	it->state->slot_struct_kind = slot_struct_kind;
42	4.95k	it->kind = result_kind;
43	4.95k	it->name = NULL;
44	4.95k	it->recursion_level = 0;
45	4.95k	it->is_at_end = false;
46	4.95k	it->is_first_run = true;
47	4.95k	it->current.sl_id = 0;
48	4.95k	memset(it->seen, 0, sizeof(it->seen));
49	4.95k	}
50
51		void
52		_PySlotIterator_Init(_PySlotIterator it, const PySlot slots,
53		_PySlot_KIND result_kind)
54	0	{
55	0	init_with_kind(it, slots, result_kind, _PySlot_KIND_SLOT);
56	0	}
57
58		void
59		_PySlotIterator_InitLegacy(_PySlotIterator it, const void slots,
60		_PySlot_KIND kind)
61	4.95k	{
62	4.95k	init_with_kind(it, slots, kind, kind);
63	4.95k	}
64
65		void
66		_PySlotIterator_Rewind(_PySlotIterator it, const void slots)
67	3.02k	{
68	3.02k	MSG("");
69	3.02k	MSG("rewind (%s slot iterator)", kind_name(it->kind));
70	3.02k	assert (it->is_at_end);
71	3.02k	assert (it->recursion_level == 0);
72	3.02k	assert (it->state == it->states);
73	3.02k	it->is_at_end = false;
74	3.02k	it->state->any_slot = slots;
75	3.02k	it->is_first_run = false;
76	3.02k	}
77
78		static Py_ssize_t
79		seen_index(uint16_t id)
80	62.4k	{
81	62.4k	return id / _PySlot_SEEN_ENTRY_BITS;
82	62.4k	}
83
84		static unsigned int
85		seen_mask(uint16_t id)
86	62.4k	{
87	62.4k	return ((unsigned int)1) << (id % _PySlot_SEEN_ENTRY_BITS);
88	62.4k	}
89
90		bool
91		_PySlotIterator_SawSlot(_PySlotIterator *it, int id)
92	30.8k	{
93	30.8k	assert (id > 0);
94	30.8k	assert (id < _Py_slot_COUNT);
95	30.8k	return it->seen[seen_index(id)] & seen_mask(id);
96	30.8k	}
97
98		// Advance `it` to the next entry. Currently cannot fail.
99		static void
100		advance(_PySlotIterator *it)
101	55.5k	{
102	55.5k	MSG("advance (at level %d)", (int)it->recursion_level);
103	55.5k	switch (it->state->slot_struct_kind) {
104	0	case _PySlot_KIND_SLOT: it->state->slot++; break;
105	47.9k	case _PySlot_KIND_TYPE: it->state->tp_slot++; break;
106	7.60k	case _PySlot_KIND_MOD: it->state->mod_slot++; break;
107	0	default:
108	0	Py_UNREACHABLE();
109	55.5k	}
110	55.5k	}
111
112		static int handle_first_run(_PySlotIterator *it);
113
114		bool
115		_PySlotIterator_Next(_PySlotIterator *it)
116	63.5k	{
117	63.5k	MSG("next");
118	63.5k	assert(it);
119	63.5k	assert(!it->is_at_end);
120	63.5k	assert(!PyErr_Occurred());
121
122	63.5k	it->current.sl_id = -1;
123
124	71.5k	while (true) {
125	71.5k	if (it->state->slot == NULL) {
126	7.97k	if (it->recursion_level == 0) {
127	7.97k	MSG("end (initial nesting level done)");
128	7.97k	it->is_at_end = true;
129	7.97k	return 0;
130	7.97k	}
131	0	MSG("pop nesting level %d", (int)it->recursion_level);
132	0	it->recursion_level--;
133	0	it->state = &it->states[it->recursion_level];
134	0	advance(it);
135	0	continue;
136	7.97k	}
137
138	63.5k	switch (it->state->slot_struct_kind) {
139	0	case _PySlot_KIND_SLOT: {
140	0	MSG("copying PySlot structure");
141	0	it->current = *it->state->slot;
142	0	} break;
143	54.0k	case _PySlot_KIND_TYPE: {
144	54.0k	MSG("converting PyType_Slot structure");
145	54.0k	memset(&it->current, 0, sizeof(it->current));
146	54.0k	it->current.sl_id = (uint16_t)it->state->tp_slot->slot;
147	54.0k	it->current.sl_flags = PySlot_INTPTR;
148	54.0k	it->current.sl_ptr = (void*)it->state->tp_slot->pfunc;
149	54.0k	} break;
150	9.53k	case _PySlot_KIND_MOD: {
151	9.53k	MSG("converting PyModuleDef_Slot structure");
152	9.53k	memset(&it->current, 0, sizeof(it->current));
153	9.53k	it->current.sl_id = (uint16_t)it->state->mod_slot->slot;
154	9.53k	it->current.sl_flags = PySlot_INTPTR;
155	9.53k	it->current.sl_ptr = (void*)it->state->mod_slot->value;
156	9.53k	} break;
157	0	default: {
158	0	Py_UNREACHABLE();
159	0	} break;
160	63.5k	}
161
162		/* shorter local names */
163	63.5k	PySlot *const result = &it->current;
164	63.5k	uint16_t flags = result->sl_flags;
165
166	63.5k	MSG("slot %d, flags 0x%x, from %p",
167	63.5k	(int)result->sl_id, (unsigned)flags, it->state->slot);
168
169	63.5k	uint16_t orig_id = result->sl_id;
170	63.5k	switch (it->kind) {
171	54.0k	case _PySlot_KIND_TYPE:
172	54.0k	result->sl_id = _PySlot_resolve_type_slot(result->sl_id);
173	54.0k	break;
174	9.53k	case _PySlot_KIND_MOD:
175	9.53k	result->sl_id = _PySlot_resolve_mod_slot(result->sl_id);
176	9.53k	break;
177	0	default:
178	0	Py_UNREACHABLE();
179	63.5k	}
180	63.5k	MSG("resolved to slot %d (%s)",
181	63.5k	(int)result->sl_id, _PySlot_GetName(result->sl_id));
182
183	63.5k	if (result->sl_id == Py_slot_invalid) {
184	0	MSG("error (unknown/invalid slot)");
185	0	if (flags & PySlot_OPTIONAL) {
186	0	advance(it);
187	0	continue;
188	0	}
189	0	_PySlot_err_bad_slot(kind_name(it->kind), orig_id);
190	0	goto error;
191	0	}
192	63.5k	if (result->sl_id == Py_slot_end) {
193	7.97k	MSG("sentinel slot, flags %x", (unsigned)flags);
194	7.97k	if (flags & PySlot_OPTIONAL) {
195	0	MSG("error (bad flags on sentinel)");
196	0	PyErr_Format(PyExc_SystemError,
197	0	"invalid flags for Py_slot_end: 0x%x",
198	0	(unsigned int)flags);
199	0	goto error;
200	0	}
201	7.97k	it->state->slot = NULL;
202	7.97k	continue;
203	7.97k	}
204
205	55.5k	if (result->sl_id == Py_slot_subslots
206	55.5k	\|\| result->sl_id == Py_tp_slots
207	55.5k	\|\| result->sl_id == Py_mod_slots
208	55.5k	) {
209	0	if (result->sl_ptr == NULL) {
210	0	MSG("NULL subslots; skipping");
211	0	advance(it);
212	0	continue;
213	0	}
214	0	if ((it->states[0].slot_struct_kind == _PySlot_KIND_MOD)
215	0	&& (it->state->slot_struct_kind == _PySlot_KIND_SLOT)
216	0	&& !(result->sl_flags & PySlot_STATIC))
217	0	{
218	0	PyErr_Format(PyExc_SystemError,
219	0	"slots included from PyModuleDef must be static");
220	0	goto error;
221	0	}
222	0	it->recursion_level++;
223	0	MSG("recursing into level %d", it->recursion_level);
224	0	if (it->recursion_level >= _PySlot_MAX_NESTING) {
225	0	MSG("error (too much nesting)");
226	0	PyErr_Format(PyExc_SystemError,
227	0	"%s (slot %d): too many levels of nested slots",
228	0	_PySlot_GetName(result->sl_id), orig_id);
229	0	goto error;
230	0	}
231	0	it->state = &it->states[it->recursion_level];
232	0	memset(it->state, 0, sizeof(_PySlotIterator_state));
233	0	it->state->slot = result->sl_ptr;
234	0	switch (result->sl_id) {
235	0	case Py_slot_subslots:
236	0	it->state->slot_struct_kind = _PySlot_KIND_SLOT; break;
237	0	case Py_tp_slots:
238	0	it->state->slot_struct_kind = _PySlot_KIND_TYPE; break;
239	0	case Py_mod_slots:
240	0	it->state->slot_struct_kind = _PySlot_KIND_MOD; break;
241	0	}
242	0	continue;
243	0	}
244
245	55.5k	if (flags & PySlot_INTPTR) {
246	55.5k	MSG("casting from intptr");
247		/* this should compile to nothing on common architectures */
248	55.5k	switch (_PySlot_get_dtype(result->sl_id)) {
249	0	case _PySlot_DTYPE_SIZE: {
250	0	result->sl_size = (Py_ssize_t)(intptr_t)result->sl_ptr;
251	0	} break;
252	0	case _PySlot_DTYPE_INT64: {
253	0	result->sl_int64 = (int64_t)(intptr_t)result->sl_ptr;
254	0	} break;
255	3.86k	case _PySlot_DTYPE_UINT64: {
256	3.86k	result->sl_uint64 = (uint64_t)(intptr_t)result->sl_ptr;
257	3.86k	} break;
258	16.2k	case _PySlot_DTYPE_PTR:
259	51.7k	case _PySlot_DTYPE_FUNC:
260	51.7k	case _PySlot_DTYPE_VOID:
261	51.7k	break;
262	55.5k	}
263	55.5k	}
264
265	55.5k	advance(it);
266	55.5k	switch (_PySlot_get_dtype(result->sl_id)) {
267	0	case _PySlot_DTYPE_VOID:
268	16.2k	case _PySlot_DTYPE_PTR:
269	16.2k	MSG("result: %d (%s): %p",
270	16.2k	(int)result->sl_id, _PySlot_GetName(result->sl_id),
271	16.2k	(void*)result->sl_ptr);
272	16.2k	break;
273	35.5k	case _PySlot_DTYPE_FUNC:
274	35.5k	MSG("result: %d (%s): %p",
275	35.5k	(int)result->sl_id, _PySlot_GetName(result->sl_id),
276	35.5k	(void*)result->sl_func);
277	35.5k	break;
278	0	case _PySlot_DTYPE_SIZE:
279	0	MSG("result: %d (%s): %zd",
280	0	(int)result->sl_id, _PySlot_GetName(result->sl_id),
281	0	(Py_ssize_t)result->sl_size);
282	0	break;
283	0	case _PySlot_DTYPE_INT64:
284	0	MSG("result: %d (%s): %ld",
285	0	(int)result->sl_id, _PySlot_GetName(result->sl_id),
286	0	(long)result->sl_int64);
287	0	break;
288	3.86k	case _PySlot_DTYPE_UINT64:
289	3.86k	MSG("result: %d (%s): %lu (0x%lx)",
290	3.86k	(int)result->sl_id, _PySlot_GetName(result->sl_id),
291	3.86k	(unsigned long)result->sl_int64,
292	3.86k	(unsigned long)result->sl_int64);
293	3.86k	break;
294	55.5k	}
295	55.5k	assert (result->sl_id > 0);
296	55.5k	assert (result->sl_id <= _Py_slot_COUNT);
297	55.5k	if (it->is_first_run && (handle_first_run(it) < 0)) {
298	0	goto error;
299	0	}
300	55.5k	return result->sl_id != Py_slot_end;
301	55.5k	}
302	63.5k	Py_UNREACHABLE();
303
304	0	error:
305	0	it->current.sl_id = Py_slot_invalid;
306	0	return true;
307	63.5k	}
308
309		/* Validate current slot, and do bookkeeping */
310		static int
311		handle_first_run(_PySlotIterator *it)
312	31.5k	{
313	31.5k	int id = it->current.sl_id;
314
315	31.5k	if (_PySlot_get_must_be_static(id)) {
316	4.78k	if (!(it->current.sl_flags & PySlot_STATIC)
317	4.78k	&& (it->state->slot_struct_kind == _PySlot_KIND_SLOT))
318	0	{
319	0	PyErr_Format(
320	0	PyExc_SystemError,
321	0	"%s requires PySlot_STATIC",
322	0	_PySlot_GetName(id));
323	0	return -1;
324	0	}
325	4.78k	}
326
327	31.5k	_PySlot_PROBLEM_HANDLING null_handling = _PySlot_get_null_handling(id);
328	31.5k	if (null_handling != _PySlot_PROBLEM_ALLOW) {
329	25.2k	bool is_null = false;
330	25.2k	switch (_PySlot_get_dtype(id)) {
331	6.55k	case _PySlot_DTYPE_PTR: {
332	6.55k	is_null = it->current.sl_ptr == NULL;
333	6.55k	} break;
334	18.7k	case _PySlot_DTYPE_FUNC: {
335	18.7k	is_null = it->current.sl_func == NULL;
336	18.7k	} break;
337	0	default: {
338		//Py_UNREACHABLE();
339	0	} break;
340	25.2k	}
341	25.2k	if (is_null) {
342	0	MSG("slot is NULL but shouldn't");
343	0	if (null_handling == _PySlot_PROBLEM_REJECT) {
344	0	MSG("error (NULL rejected)");
345	0	PyErr_Format(PyExc_SystemError,
346	0	"NULL not allowed for slot %s",
347	0	_PySlot_GetName(id));
348	0	return -1;
349	0	}
350	0	if (it->states[0].slot_struct_kind == _PySlot_KIND_SLOT) {
351	0	MSG("deprecated NULL");
352	0	if (PyErr_WarnFormat(
353	0	PyExc_DeprecationWarning,
354	0	1,
355	0	"NULL value in slot %s is deprecated",
356	0	_PySlot_GetName(id)) < 0)
357	0	{
358	0	return -1;
359	0	}
360	0	}
361	0	else {
362	0	MSG("unwanted NULL in legacy struct");
363	0	}
364	0	}
365	25.2k	}
366
367	31.5k	_PySlot_PROBLEM_HANDLING duplicate_handling = _PySlot_get_duplicate_handling(id);
368	31.5k	if (duplicate_handling != _PySlot_PROBLEM_ALLOW) {
369	27.8k	if (_PySlotIterator_SawSlot(it, id)) {
370	0	MSG("slot was seen before but shouldn't be duplicated");
371	0	if (duplicate_handling == _PySlot_PROBLEM_REJECT) {
372	0	MSG("error (duplicate rejected)");
373	0	PyErr_Format(
374	0	PyExc_SystemError,
375	0	"%s%s%s has multiple %s (%d) slots",
376	0	kind_name(it->kind),
377	0	it->name ? " " : "",
378	0	it->name ? it->name : "",
379	0	_PySlot_GetName(id),
380	0	(int)it->current.sl_id);
381	0	return -1;
382	0	}
383	0	if (it->states[0].slot_struct_kind == _PySlot_KIND_SLOT) {
384	0	MSG("deprecated duplicate");
385	0	if (PyErr_WarnFormat(
386	0	PyExc_DeprecationWarning,
387	0	0,
388	0	"%s%s%s has multiple %s (%d) slots. This is deprecated.",
389	0	kind_name(it->kind),
390	0	it->name ? " " : "",
391	0	it->name ? it->name : "",
392	0	_PySlot_GetName(id),
393	0	(int)it->current.sl_id) < 0) {
394	0	return -1;
395	0	}
396	0	}
397	0	else {
398	0	MSG("unwanted duplicate in legacy struct");
399	0	}
400	0	}
401	27.8k	}
402	31.5k	it->seen[seen_index(id)] \|= seen_mask(id);
403	31.5k	return 0;
404	31.5k	}