Commit Graph
1534 Commits
Author SHA1 Message Date
Joshua Megnauth 7ec2682153 ucd: Rewrite parser to be faster & more flexible (#8611)
Related: #8599

My original parser was monolithic and inflexible. It worked as intended
for the derived data files, but anything more complicated required hacky
code. For example, the original parser always expected to build a vector
of values, yet sometimes we required other data structures such as
BTreeMaps.

I split up the parser into helper functions that are both cleaner and
more flexible. The actual parser should still yield the same results -
this doesn't "fix" anything yet. However, this is preliminary work for
fixing more of UCD since we will need a more flexible parser for fixes
like the linked PR.
2026-09-01 08:48:52 +09:00
Jeong, YunWon 6aac4653e6 Fix post-merge subinterpreter lifecycle issues (#8632)
Preserve logical memoryview descriptors across interpreter transfers, make channel-end release idempotent, and scope runtime-owned interpreter cleanup to the creating top-level runtime. Re-read owned interpreters during shutdown so finalizers cannot leave newly-created children behind.

Add regression coverage for sliced and cast memoryviews, repeated channel release, and multiple embedded runtimes.

Assisted-by: Codex:GPT-5
2026-09-01 08:47:43 +09:00
Jeong, YunWon 516a116f9a Name the function a failed argument binding was binding for (#8630)
* Name the function a failed argument binding was binding for

A built-in call that binds badly reported neither the function nor, for a
method, the right numbers: `self` was prepended before binding, so it was
counted as both an expected parameter and a given argument. `[].append()`
read `expected at least 2 arguments, got 1`.

`Callee` carries what a message says about the function: the name, and
whether the leading argument fills the instance parameter. `PyNativeFn`
takes one, `PyNativeFunction` and `PyMethodDescriptor` supply it, and the
four method-descriptor call specializations in `frame.rs` do the same.
`bind_for` subtracts the instance from both numbers.

The messages now read as their counterparts do:

- `_PyArg_CheckPositional`: `find expected at least 1 argument, got 0`,
  with the singular when the count is one.
- `_PyArg_UnpackKeywords`: `split() got an unexpected keyword argument
  'bogus'`, and `cast() missing required argument 'format' (pos 1)` for a
  parameter a call may pass by name. A positional-only parameter is only
  ever counted, so it keeps the first form.

A binding that happens where the name isn't known leaves it off, the way
`_PyArg_Parser.fname` is NULL.

`test_find_etc_raise_correct_error_messages` now passes in both
`test_bytes` and `string_tests`.

Assisted-by: Claude

* Name the type whose constructor or initializer bound the arguments

`Constructor::slot_new` and `Initializer::slot_init` bound their arguments
without a name, and so did the slots that override them, so a constructor
that was called wrongly said only `expected 1 argument, got 0`.

Both defaults and every override now name the type the slot was written
for, not the subclass being constructed and not the module `tp_name`
carries: `float expected at most 1 argument, got 2`, and `deque expected
at most 2 arguments, got 3` for a `deque` subclass.

`slice()` and `range()` counted their own arguments and raised messages of
their own; they now raise the one `_PyArg_CheckPositional` raises, which
makes `test_range_constructor_error_messages` pass.

Assisted-by: Claude
2026-09-01 06:57:58 +09:00
Jeong, YunWon 306f104847 codecs: address post-merge review findings (#8623)
Assisted-by: Codex:GPT-5
2026-08-31 18:52:34 +09:00
Jeong, YunWon 322f294a21 common: add VM-independent codec and text engines (#8622)
* common: add PyPy CJK codec engines

Assisted-by: Codex:GPT-5

* common: mark CJK mapping tables generated

Assisted-by: Codex:GPT-5

* common: add reusable byte and text engines

Assisted-by: Codex:GPT-5

* common: record opt-in engine dependencies

Assisted-by: Codex:GPT-5

* stdlib: add `_multibytecodec` and the six `_codecs_*` modules

Wire the CJK codec engines in `rustpython-common` up to the VM. `_multibytecodec`
holds `MultibyteCodec`, `MultibyteIncrementalEncoder`, `MultibyteIncrementalDecoder`,
`MultibyteStreamReader` and `MultibyteStreamWriter`, the encode/decode drivers and
the error-handler protocol; each `_codecs_*` module exposes `getcodec` for the
encodings of its region.

`rustpython-stdlib` now enables the `cjk-codecs` feature of `rustpython-common`.

Add `cjk::decode_reset`, which the decoder `reset()` methods need. It differs from
building a fresh decoder state: ISO 2022 keeps its G1..G3 designations and the
escape-throughout flag, and resets only G0 and the shifted flag.

Drop the markers from the CJK codec tests and from the `test_codecs`, `test_io`,
`test_email`, `test_zipfile` and `test_traceback` cases that needed a CJK codec.
`test_codecs.BasicUnicodeTest.{test_basics,test_decoder_state}` stay expected
failures for an unrelated reason: `codecs.charmap_encode` rejects a `None` mapping.

Assisted-by: Claude Code:claude-opus-5

* stdlib: use the byte and text engines from `rustpython-common`

`binascii`, `_json` and `_socket`'s address converters now call the engines in
`rustpython-common` instead of carrying their own copies, and `rustpython-stdlib`
enables the `binascii`, `inet` and `json` features for them. That leaves
`base64` and `crc32fast` with no caller in `rustpython-stdlib`, and
`crates/stdlib/src/json/machinery.rs`, the last of the json_in_type-derived code,
goes away with its last caller.

The address converters change behaviour. `inet_aton` reads the lenient forms
(`127.1`, `16909060`, `0x7f.1`, `0177.0.0.1`), `inet_pton` rejects an octet with a
redundant leading zero and a group of five hex digits, `inet_ntop` writes the
IPv4-compatible form as `::c000:201`, and an address family with no converter
raises `EAFNOSUPPORT` instead of a bare `OSError`.

Give the JSON engine the closing-quote scan and the allocation-free `\uXXXX`
escape it needs to carry `_json`'s workload. Against the code it replaces,
`json.dumps` runs 2.3x faster with `ensure_ascii=True` and 1.7x without it, and
`json.loads` 1.2x.

`binascii.a2b_base64` now reports the messages `binascii.c` does: no
`error decoding base64: ` prefix, and the data-character count in parentheses.

Assisted-by: Claude Code:claude-opus-5

* test: enable the Windows cp932 codec case

The shared CJK engine now satisfies the Windows code-page adapter, so keeping this test marked as an expected failure turns its success into a CI failure.

Assisted-by: Codex:GPT-5
2026-08-31 15:44:55 +09:00
Hanjeong Lee d1bbf4bc1a Report every generated __text_signature__, and keep it out of __doc__ (#8614)
* Strip the signature prefix from builtin __doc__

A function's signature and its documentation share one string, separated
by `\n--\n\n`, as in CPython. __text_signature__ read the front of it,
but __doc__ returned the whole thing:

    >>> len.__doc__
    'len(obj, /)\n--\n\nReturn the number of items in a container.'   # was
    'Return the number of items in a container.'                      # now

44 of the 46 builtin functions leaked the prefix.

get_doc_from_internal_doc already stripped it but was reachable only from
PyType.__doc__. Split it the way CPython does, into doc_without_signature
(_PyType_DocWithoutSignature) and a wrapper mapping an empty result to
None (_PyType_GetDocFromInternalDoc), and call it from PyNativeFunction
and PyMethodDescriptor as well.

Assisted-by: Claude Code:claude-opus-5

* Terminate a generated __text_signature__ that carries no documentation

A signature and its documentation share one string, separated by
`\n--\n\n`, and readers find the signature by searching for that marker.
A #[pyfunction] with no doc comment stored the bare signature, which no
reader could parse:

    >>> time.clock_getres.__doc__
    'clock_getres(clk_id, /)'
    >>> time.clock_getres.__text_signature__
    None

Emit the marker in that case too, as Argument Clinic does for an
undocumented function. 136 of the 915 functions reachable from the
importable modules were affected.

__doc__ now reports None for them, matching CPython, because nothing
follows the marker.

Assisted-by: Claude Code:claude-opus-5

* Report a __text_signature__ for every method

A #[pymethod] built its doc only when the method carried a doc comment,
so one without a comment dropped the generated signature too:

    >>> list.append.__text_signature__
    None

Build it from either part, as #[pyfunction] does. All 1101 method
descriptors reachable from the builtin types now report a signature, up
from 1, and 713 of the 1030 that CPython also describes match it exactly.

A method that takes its receiver as an ordinary first argument instead of
`&self` reported that argument by name, so binding the method could not
drop it:

    >>> inspect.signature([].__dir__)
    (obj, /)     # was
    ()           # now

Mark it $self, or $type for a classmethod, as CPython does. 310 methods
were affected.

test_unbound_builtin_method_noargs and test_bound_builtin_method_noargs
pass now.

Assisted-by: Claude Code:claude-opus-5

* Drop the expectedFailure on test_simple_completion

rlcompleter closes the parenthesis for a callable whose signature takes
no parameters, and leaves it open when the signature cannot be read:

    def _callable_postfix(self, val, word):
        if callable(val):
            word += "("
            try:
                if not inspect.signature(val).parameters:
                    word += ")"
            except ValueError:
                pass

os.getpid reports `()` since the generated signature carries the `--`
terminator, so completing `os.getpid` yields `os.getpid()` and the test
passes.

Assisted-by: Claude Code:claude-opus-5

* Name every #[pymethod] receiver zelf

A method that needs an owned handle cannot take `&self`, so it takes the
receiver as its first argument and names it `zelf`, `self` being a Rust
keyword. 24 of the 163 such methods named it something else: `instance`
(11), `obj` (4), `exc` (3), `_self` (3), `_instance` (2).

Rename them. The generated signature is unaffected either way, since the
macro marks the receiver by position rather than by name.

Assisted-by: Claude Code:claude-opus-5

* Drop the unreachable zelf name check in func_sig

The receiver is now marked by position, so the name it carries no longer
matters, and no path reaches this check with an argument named zelf:

- a #[pymethod] or #[pyclassmethod] without a `&self` receiver has its
  first argument replaced by the marker before the name is read
- a `&self` receiver is handled as syn::FnArg::Receiver
- a #[pymethod(raw)] is passed to static_raw_func, whose PyNativeFn bound
  fixes its signature to (&VirtualMachine, FuncArgs)
- no #[pystaticmethod] or #[pyfunction] names an argument zelf
- #[pymember], #[pygetset] and #[pyslot] never reach func_sig

Every generated signature is byte for byte identical without it.

Assisted-by: Claude Code:claude-opus-5

* Keep the argument bundle when marking the receiver

A #[pyclassmethod] that takes FuncArgs receives the class inside the
bundle along with every other argument, but the marker was spent on the
bundle and the arguments went unreported:

    >>> object.__subclasshook__.__text_signature__
    '($type, /)'                    # was, claims it takes nothing
    '($type, *args, **kwargs)'      # now

Report both, the shape CPython uses for __new__. Two methods take their
arguments this way, __subclasshook__ on object and on type.

Assisted-by: Claude Code:claude-opus-5
2026-08-31 14:23:29 +09:00
Jeong, YunWon 5b1a1c08d7 Leave a byte that starts no UTF-8 sequence at the end of a console write (#8621)
* Leave a byte that starts no UTF-8 sequence at the end of a console write

`find_last_utf8_boundary` read every byte at or above 0xc0 as the start of a
sequence, giving 0xf8..=0xff an expected length of 4 and cutting the tail back
to before it.  `_find_last_utf8_boundary` stops the four-byte range at 0xf8 and
returns the full length for anything above it, leaving the byte for
MultiByteToWideChar to answer with U+FFFD.

`write_console_utf8` therefore reported fewer bytes written than it was given
whenever one of those bytes fell in the last three, and for a buffer that began
with one it cut the length to 0, converted nothing and returned Ok(0) -- a
write that never advances.

The scan also ran a fourth iteration the C loop does not; the arms happen to
answer the same there, but the bound is now the same 3.

* Drop the expectedFailure on test_winconsoleio's test_write

The marker went stale with the boundary fix in the parent commit.  The test
writes `b'\xff'*10` and `data + b'\xff'` to CONOUT$ and asserts the returned
count, which is the case `find_last_utf8_boundary` was answering wrong, so
regrtest now reports it as an unexpected success.
2026-08-30 23:35:08 +09:00
Lee Dogeon 578217e1f6 Fix tuple subclass preservation in type bases (#8420)
* Fix tuple subclass preservation in type bases

Assisted-by: Codex:gpt-5.6-sol

* Refine type bases representation

Store validated base classes in the original typed tuple, while retaining a bootstrap vector only until a Python tuple can be materialized.

Assisted-by: gpt-5.6-sol
Assisted-by: Codex:gpt-5.6-sol

* Bootstrap tuple type with type hierarchy

Initialize tuple and the canonical empty tuple alongside type and object so every type stores an actual typed bases tuple from construction. Remove the bootstrap bases representation and keep raw initialization Miri-safe.

Assisted-by: Codex:gpt-5.6-sol
2026-08-30 22:54:22 +09:00
김은빈 8b65a5455f feat: reuse weak callable proxy (#8618) 2026-08-30 17:28:46 +09:00
Jeong, YunWon 2c8d3ce50b Implement PEP 667 frame locals semantics (#8602)
* Implement PEP 667 frame locals semantics

Assisted-by: Codex:GPT-5

* Fix C API test CString import

Assisted-by: Codex:GPT-5

* Address PEP 667 review findings

Assisted-by: Codex:GPT-5
2026-08-30 17:20:33 +09:00
Lee Dogeon a21377a97b Match uuid.getnode() native node detection to CPython (#8612)
* uuid: expose stable hardware node

Cache native MAC address detection and advertise an extractable node only when a hardware address is available. This lets uuid.getnode() use the native UUID path while preserving its existing fallbacks.

Assisted-by: Codex:gpt-5.6-sol

* Prefer universally administered MAC addresses

Match uuid.getnode()'s documented interface-selection rule by scanning available addresses before falling back to a locally administered one. Ignore zero addresses and cover the selection behavior with Rust unit tests.

Assisted-by: Codex:gpt-5.6-sol
2026-08-30 16:14:36 +09:00
Jeong, YunWon 7c6c78f955 Implement CPython 3.14 subinterpreter APIs (#8605)
* Add _interpreters and _interpchannels modules

Apply the patch baseline for the low-level subinterpreter modules:

- crates/vm/src/stdlib/_interpreters.rs: create/destroy/list_all/get_main/
  get_current/is_running/exec/call/run_string/run_func/set___main___attrs/
  is_shareable/whence and the Interpreter*Error exceptions
- crates/vm/src/stdlib/_interpchannels.rs: channel create/destroy/send/recv/
  list_all/list_interpreters/release/close and the Channel*Error exceptions
- crates/vm/src/vm/crossinterp.rs: cross-interpreter data protocol
- crates/vm/src/vm/{interpreter,mod,runtime,vm_new}.rs: interpreter registry
  and lifecycle plumbing the modules need
- Lib/concurrent/interpreters/: high-level PEP 734 package

Assisted-by: Claude:claude-opus-5

* Correct _interpreters and _interpchannels against CPython 3.14

Argument matching:
- Add `function::ArgSpec`, a `PyArg_ParseTupleAndKeywords` equivalent that
  applies the `|`, `$` and `:` markers of a format string to a `kwlist`, and
  route every module function of both modules through it. This enforces
  keyword-only parameters, rejects unexpected keywords, accepts keyword forms
  that were previously positional-only (`whence(id=)`, `get_config(id=)`,
  `set___main___attrs(id=, updates=)`, `capture_exception(exc=)`,
  `_register_end_types(send=, recv=)`), and reproduces the arity messages.
- `O!` slots (`shared`, `updates`, `call`'s `args`/`kwargs`) now reject None,
  and `_PyArg_BadArgument` renders None as "None" rather than "NoneType".
- `new_config` takes at most one positional `str`; `list_all` of
  `_interpchannels` is argument-less.
- Convert arguments in `kwlist` order, so an argument's own error is raised
  ahead of the checks that follow it.

_interpreters:
- Add the `CrossInterpreterBufferView` type and build the received memoryview
  on it, keeping the sending interpreter's exporter out of the destination.
- Build `excinfo.errdisplay` from `traceback.TracebackException`.

Feature flags:
- `os.fork` checks finalization before `allow_fork`, matching `os_fork_impl`.
- `_thread.start_new_thread` and `start_joinable_thread` reject an interpreter
  without `allow_threads`.

Lib/concurrent/interpreters/_crossinterp.py: restore the stripped docstrings
and comments.

Assisted-by: Claude:claude-opus-5

* Correct the stateless checks and error shapes of _interpreters against CPython 3.14

verify_stateless_function follows _PyFunction_VerifyStateless: it rejects
non-dict builtins, a non-empty __defaults__, __kwdefaults__ or __closure__,
and code whose LOAD_GLOBAL names are held by the function's globals or
absent from its builtins.

code_returns_only_none follows _PyCode_ReturnsOnlyNone: generator,
coroutine and async-generator code is rejected up front, the instruction
walk skips inline caches and maps specialized and instrumented opcodes
back, and the LOAD_CONST preceding each RETURN_VALUE is compared against
the index of None in co_consts.

ExcInfo::capture keeps an empty exception message instead of dropping it,
and builds `formatted` as `module.qualname: msg`, leaving out the builtins
and __main__ modules.

_interpreters.call packs the callable through _PyFunction_GetXIData before
pickle and re-raises the stateless-check failure when both fail. A func,
args or kwargs that cannot be rebuilt in the target, and a result without
cross-interpreter data, now raise NotShareableError with the snapshot as
the cause rather than being returned as excinfo.

_interpreters.capture_exception() without an argument returns None.

pickle_loads and _PyFunction_GetXIData attach the underlying failure as
__cause__.

channel_send converts the object to cross-interpreter data after the
channel's `closing` check.

ChannelID rich comparison returns the result of comparing its id with the
other number instead of coercing that result to bool.

PyMemoryView_FromObjectAndFlags raises "memoryview: a bytes-like object is
required, not 'X'" for an object that is not a buffer.

Assisted-by: Claude:claude-opus-5

* Correct cross-interpreter data conversion and channel argument parsing

Bound shareable ints by isize, raising OverflowError("try sending as
bytes") outside that range and keeping it as the NotShareableError cause.

Report an unshareable object by its repr, and attach a failing conversion
as __cause__ of the NotShareableError raised for the object it was called
for, so each level of a nested tuple appears in the chain.

Guard each tuple item conversion with with_recursion("while sharing a
tuple").

Gate the memoryview getdata function on `_interpreters` having been
imported, and route channel_send_buffer through a memoryview so it uses
that function and the resolved fallback.

Create the cross-interpreter exception types from the module_exec of
either module that raises them, instead of only `_interpreters`.

parse_cid raises OverflowError("int too big to convert"); int_arg
reproduces the `i` converter's three overflow messages and is also used
while parsing channel_send arguments.

Add BASETYPE to _queue.Empty, and gate nt.execv/nt.execve on allow_exec.

Assisted-by: Claude:claude-opus-5

* Correct interpreter ID parsing and the channel_send defaults lookup

_PyInterpreterState_ObjectToID accepts any object with __index__, raises
OverflowError("int too big to convert") outside the int64 range, and
reports a negative ID with the repr of the original object.

channelsmod_send reads the channel's default unboundop and fallback only
when one of the two arguments is negative, so an explicit pair is
validated before the channel is looked up.

Assisted-by: Claude:claude-opus-5

* Add the _interpqueues module and concurrent.interpreters._queues

_interpqueues holds a process-wide queue table and exposes create,
destroy, list_all, put, get, bind, release, get_maxsize,
get_queue_defaults, is_full, get_count and _register_heap_types, raising
QueueError and QueueNotFoundError.  QueueEmpty and QueueFull, which
subclass queue.Empty and queue.Full, are registered per interpreter by
concurrent.interpreters._queues.

Cross-interpreter data carries a queue as a refcounted queue ID that
binds when the data is captured and releases when it is dropped, and
is_shareable reports a registered Queue as shareable.

Queue and channel items owned by an interpreter are now cleared from
Interpreter::finalize, after module finalization, rather than from
destroy_owned_interpreter, so values sent by an atexit callback also
become unbound.

is_shareable gates memoryview on the same registration flag as the
getdata lookup.

Assisted-by: Claude:claude-opus-5

* Add the high-level concurrent.interpreters API

Interpreter, ExecutionFailed and the queue aliases, copied verbatim from
CPython 3.14.

Assisted-by: Claude:claude-opus-5

* Destroy leftover subinterpreters when the main interpreter finalizes

Interpreter::finalize now runs finalize_subinterpreters between the atexit
handlers and the finalizing flag: when the main interpreter still owns
subinterpreters it emits the RuntimeWarning "remaining subinterpreters;
close them with Interpreter.close()" and then finalizes each of them.

runtime::owned_interpreter_ids lists the runtime-owned interpreters.

Assisted-by: Claude:claude-opus-5

* Absolutize the script path in run_file

_Py_abspath and _PyPathConfig_ComputeSysPath0 arrive as abs_path and
script_sys_path0. run_file hands the absolutized path to get_importer
and to the runner, so __file__ and co_filename no longer stay relative,
and inserts the symlink-resolved script directory as sys.path[0]
instead of the argument's parent.

test_cmd_line_script.test_script_abspath no longer expects a failure.

Assisted-by: Claude:claude-opus-5

* Name types in error messages the way tp_name does

The object, number, sequence and mapping protocols, the
unsupported-operand helpers, and the type-specific messages fed from
them now read PyType::slot_name() where they read PyType::name(),
so a type declared with a module keeps it.

Message texts corrected along the way:
- PySequence_Size, PyMapping_Size, PySequence_GetItem and
  PySequence_SetItem/DelItem split their merged wording in two, and
  PyObject_SetItem/DelItem say "object".
- PyObject_GenericSetAttr reports a read-only attribute and the
  missing __dict__.
- check_class drops the type name it appended.
- __int__ and __index__ drop the class prefix; __float__ keeps it.
- float(), complex(), round(), next(), str subscripting and list
  subscripting take their own wording.
- str.join and bytes.join number the item they turn down and name what
  they wanted, and report a non-iterable as "can only join an
  iterable".

test_class.testObjectAttributeAccessErrorMessages,
string_tests.test_subscript and the test_descrtut doctest no longer
expect a failure.

Assisted-by: Claude:claude-opus-5

* Gate script_code's source compilation on the compiler feature

crossinterp::script_code called vm.compile unconditionally, which only
exists with the rustpython-compiler feature. Builds without it, such as
example_projects/barebone, now raise a TypeError instead of failing to
compile.

Assisted-by: Claude:claude-opus-5

* Skip test_pyinit_function_raises_exception

The test imports _testsinglephase in its body without a decorator
guarding it, and now that _interpreters exists requires_subinterpreters
no longer skips it.

Assisted-by: Claude:claude-opus-5
2026-08-30 13:45:54 +09:00
Jeong, YunWon c47e4170f5 posixsubprocess: call libc setgroups directly in the child (#8609)
`setgroups_if_needed` was compiled out on macOS, so `extra_groups` was
accepted and then silently ignored there.  nix gates `unistd::setgroups`
off `apple_targets`, `redox` and `haiku`; calling `libc::setgroups` and
checking the return with `nix::Error::result` is the shape the adjacent
`setregid_if_needed` and `setreuid_if_needed` already use, and libc
declares the function everywhere except redox.

`u32` and `libc::gid_t` have the same layout, so the caller's slice is
passed as-is instead of being collected into a fresh `Vec` after fork
and before exec.  `ngroups` is `c_int` on the BSDs and `size_t` on
linux, hence `as _`.

Assisted-by: Claude
2026-08-30 10:52:35 +09:00
Jeong, YunWon 6658ffa717 memoryview: traverse the view for the collector, and name types as tp_name does (#8608)
* memoryview: walk the view and the buffer wrapper for the collector

Neither `memoryview` nor the `_buffer_wrapper` a `__buffer__` produces was
traversed, so the object a view looks at was never reported and a cycle
running through one was classified as reachable:

    class Src:
        def __buffer__(self, flags): return memoryview(b'abcdef')
    o = Src(); o.keep = memoryview(o)   # o is never freed

Both now report what they hold, as `memory_traverse` and `mbuf_traverse` do.

Assisted-by: Claude

* Name the type in an unhashable-type message the way `tp_name` does

The message took the short name, so a type defined in a module lost the
module: `hash(array.array('B', b'a'))` said `unhashable type: 'array'`
where the name is `array.array`, and `collections.deque` said `'deque'`.
`slot_name()` is what `tp_name` holds, and it leaves a class defined in
Python reported by its own name as before.

Assisted-by: Claude
2026-08-29 23:00:31 +09:00
Jeong, YunWon f9b177719b Fix formatting, numeric, unicode, codec, complex and marshal mismatches found by differential testing (#8600)
* Fix %-formatting of bytes precision, width and %c errors

`format_bytes` subtracted the byte length from the field width without
saturating, so `b'%1s' % (b'abcde',)` aborted with a capacity overflow.
A precision written as a bare dot now truncates to nothing, and `%r`/`%a`
on bytes now honour the precision and width like the other conversions.

`%c` with a bytes, bytearray or str argument that is not one unit long
now names the argument by its length instead of by its type.

Assisted-by: Claude Code:claude-opus-5

* Fix format spec handling of grouping, bool, 'c' and complex

A grouping option next to an unrecognised presentation type now reports
"Cannot specify ',' with 'a'." instead of falling through to the type
check. `format(True, spec)` now validates the spec the way an int does.

The 'c' type now pads and aligns its character, and an integer outside
the C long range raises OverflowError rather than reporting a code point
out of range.

A complex formatted with the 'n'/'g' types or with a precision and no
type now goes through the general format without forcing a fraction.

Assisted-by: Claude Code:claude-opus-5

* Round floats at a negative ndigits from the exact decimal digits

Dividing by a power of ten rounded twice: once when the quotient was
stored and again at the tie, so e.g. `round(2.5e2, -2)` came out as 300.0.
The digits now come from the exact decimal expansion of the value.

Assisted-by: Claude Code:claude-opus-5

* Report the requested base in int literal errors and reject a bare sign

An invalid literal parsed with base 0 named the base that the prefix
turned out to mean rather than 0. A string of nothing but a sign was
taken for the old octal form and returned 0 instead of raising.

Assisted-by: Claude Code:claude-opus-5

* Split, strip and expand tabs over the Py_UNICODE_ISSPACE set

`str.split`, `rsplit`, `strip`, `lstrip` and `rstrip` with no separator
used Rust's whitespace predicate, which differs from the 29 code points
`Py_UNICODE_ISSPACE` names: U+001C-U+001F and U+0085 were skipped and
U+200B was treated as a separator.

`expandtabs` went through `str`, so it dropped the lone surrogates of a
WTF-8 string; it now works on `Wtf8` throughout.

Indexing a str out of range now says "string index out of range".

Assisted-by: Claude Code:claude-opus-5

* Read Unicode numeric values as exact rationals

`DerivedNumericValues.txt` field 1 carries a rounded decimal, so
`unicodedata.numeric('⅐')` and its neighbours came back short of the
value CPython reports. The generator now reads the rational in field 3,
and takes the 3.2 values from field 8 of `UnicodeData-3.2.0.txt`.

Assisted-by: Claude Code:claude-opus-5

* Return a mappingproxy from Pattern.groupindex

`pattern_groupindex` wraps the group index in a dict proxy, and hands
back a plain dict only when the pattern has no named group.

Assisted-by: Claude Code:claude-opus-5

* Fix the utf-16/32/7 codecs' error handling

The utf-32 decoder dropped a code point above U+10FFFF instead of calling
the error handler, and both the utf-16 and utf-32 handlers were told the
encoding was "utf-16"/"utf-32" whichever byte order the data was in.

The encoders now take a bytes replacement from the handler as it stands,
rejecting one that does not fill whole code units, rather than iterating
over it as text; a str replacement from the utf-16 encoder now splits an
astral code point into a surrogate pair.

The utf-7 decoder names its encoding "utf7", as its codec does.

Assisted-by: Claude Code:claude-opus-5

* Rework complex multiplication, division and power

Division now divides by whichever part of the divisor is larger, the way
`_Py_c_quot` does, and both it and multiplication recover the infinities
that the plain formulas turn into nan, following C11 Annex G. An operand
that is a real number is now multiplied and divided component-wise, which
keeps the sign of a zero and the other part of an infinity; a real
numerator has its own quotient so that its zero keeps a sign too.

An integer exponent no greater than 100 in magnitude is now reached by
repeated multiplication rather than through the polar form, so e.g.
`(1+2j) ** 2` is exact. A zero exponent gives 1, and an exponent with no
imaginary part no longer reaches for a logarithm that turns an infinite
magnitude into a nan. A result that came out infinite raises
OverflowError.

`complex() arg is a malformed string` is replaced by `could not convert
string to complex: ...` when the string carries a misplaced underscore,
`complex division by zero` by `division by zero`, and the message for
zero raised to a negative or complex power no longer names the base.

Assisted-by: Claude Code:claude-opus-5

* Intern the string constants that read as names

A code object's string constants were interned by length, so a short
string that is not a name was interned and a long name was not. They are
now picked out the way `all_name_chars` does. The one-character latin-1
strings are interned as well, so that every route to one of them lands on
the same object.

Assisted-by: Claude Code:claude-opus-5

* Honour the marshal version and separate its EOF errors

Versions below 2 now write a float or complex as its digits under
TYPE_FLOAT/TYPE_COMPLEX, versions from 4 on write a tuple of fewer than
256 items under TYPE_SMALL_TUPLE and a long ascii string under
TYPE_ASCII, and a string is marked interned only when it is.

`marshal.loads` now tells apart the three ways its data can run out:
"EOF read where object expected" where an object was to start, "EOF read
where not expected" where a single byte was, and "marshal data too short"
where a run of bytes was cut short.

Assisted-by: Claude Code:claude-opus-5
2026-08-29 22:43:11 +09:00
Jeong, YunWon 0ae835a073 Give heap types a dict namespace (#8606)
Replace `PyType::attributes` (`PyRwLock<PyAttributes>`) with a `TypeNamespace`
enum. A type created while an interpreter is running holds a `PyDict`; the
types `Context::genesis` and `PyType::new_static` build keep the interned-key
`IndexMap`, since hashing a string needs a VM.

`type.__new__` binds `__classdictcell__` to the type's own namespace rather
than the namespace dict passed to it, so an annotation scope reads attribute
changes made after the class body ran. Removes the `expectedFailure` on
`test_type_params.TypeParamsClassScopeTest.test_modified_later`.

`PyGetSet` holds its class as a `PyRef<PyType>` instead of a non-owning
`PointerSlot`, and traverses it, because a namespace can outlive the type it
belongs to. `PointerSlot` and the `unsafe` on `Context::new_getset` are gone.

`subs_parameters` raises `TypeError` when `__typing_subst__` returns a
non-tuple in an unpack position, using the new
`PyType::fully_qualified_name` for the message. Removes the
`expectedFailure` on
`test_typing.GenericTests.test_return_non_tuple_while_unpacking`.

Assisted-by: Claude
2026-08-29 21:12:40 +09:00
Jeong, YunWon 17deb6af5b lock: add an opt-in rwlock that detaches before it blocks (#8556)
* lock: add an opt-in rwlock that detaches before it blocks

A thread blocked acquiring a lock reaches no safepoint, so stop-the-world
cannot stop it, and the lock it waits for is routinely one a thread the
requester already suspended is holding. `RawDetachingRwLock` wraps the raw
rwlock and hands the wait for a contended acquire to a hook that leaves the
interpreter first; an acquire that takes the lock on its first try does not
reach the hook. The vm installs the hook during interpreter init and
implements it with `allow_threads`.

The wait ends with the lock acquired while detached, so re-attaching can park
the thread holding it. That is only safe where nothing reachable from a
stop-the-world section takes the same lock, so it is opt-in per lock:
`PyDetachingRwLock` is a separate type from `PyRwLock`, and `Traverse` is not
implemented for it, so a payload holding one cannot derive `Traverse`.

`PyByteArray::inner` takes it. `BorrowedValue`/`BorrowedValueMut` gain the
matching mapped-guard variants.

`a_thread_blocked_on_a_lock_does_not_stall_stop_the_world` blocks an
interpreter thread on a `PyDetachingRwLock` and asserts stop-the-world still
completes, running the stop on its own thread with a timeout so a stop that
never completes fails rather than hangs. Without the hook installed it fails
on the 10 s timeout; with it, it passes in 0.07 s.

Assisted-by: Claude

* lock: stop detaching where the lock may already be held

`upgrade` runs with the upgradable lock held, and `lock_shared_recursive` may
be the re-entrant take of a lock the calling thread holds; detaching there
parks a thread holding the lock, which is what this type documents it must not
do. They forward to the wrapped lock instead. `lock_upgradable` starts from
holding nothing, but nothing takes an upgradable read of one of these, so it
forwards too. `lock_shared` and `lock_exclusive` still detach.

Also narrow two claims the comments overstated. Not implementing `Traverse`
enforces the opt-in rule only against collections, not against the other things
that stop the world. And the requester exemption the hook relies on is wider
than `_PyEval_StopTheWorld` gives, so it is a local invariant.

Assisted-by: Claude

* os.readinto: read aside when the fd can wait

`readinto` held the destination's write lock for the whole call, including the
`read(2)` inside `allow_threads`. On a pipe, socket or terminal that read
returns only when the other end writes, so a thread reaching the same object
waited on a lock for an unbounded time, reaching no safepoint while it did.

Take the fd that answers without waiting directly, as before, and otherwise
read into scratch and take the lock only for the copy. This is what
`FileIO.readinto`, `socket.recv_into` and `socket.recvfrom_into` already do;
`os.readinto` was the site left over.

The EINTR retry moves to `read_into_slice`, unchanged.

Assisted-by: Claude

* fcntl: detach around the calls that wait

Every call in this module ran with the thread attached, so a thread inside one
reached no safepoint until it returned. `flock(LOCK_EX)` and `lockf(F_LOCK)`
return when whoever holds the lock gives it up, which may be never, and an
ioctl on a terminal or socket answers when the device is ready to; the world
could not be stopped for that long. `fcntl_fcntl_impl`, `fcntl_ioctl_impl`,
`fcntl_flock_impl` and `fcntl_lockf_impl` all release around the call.

`ioctl` with `mutate_flag` additionally held the target's write lock for the
whole call, so a thread reaching the same object waited on a lock for as long
as the device took. Its bytes now go in and come back through a buffer of our
own, as `fcntl_ioctl_impl` copies through one of its own for anything up to
IOCTL_BUFSZ. The export the argument holds is what keeps the length from
changing in between.

test_fcntl and test_ioctl pass.

Assisted-by: Claude

* openssl: read aside instead of holding the caller's buffer locked

`SSLSocket.read` wrote straight into the destination buffer, holding the lock
that reaching its bytes takes for the whole call. That read returns when the
peer writes, which may be never, so a thread touching the same object waited on
that lock for as long as the peer took, reaching no safepoint while it did.

Read into a buffer of our own and take the destination's lock only for the
copy. The rustls backend already reads this way, and `_ssl__SSLSocket_read_impl`
works from a `Py_buffer` whose critical section ended before the read.

`test_ssl` on this backend fails the same 16 tests before and after.

Assisted-by: Claude

* vm: add the inverse of allow_threads for callbacks

A call that detaches hands the thread to stop-the-world, which counts it as
parked. A callback that reaches Python from inside such a call would then run
on a thread the requester believes is stopped, and nothing in the vm could
stop it: `attach_thread` and `detach_thread` are private to `thread.rs`, and
`allow_threads` only goes the one way.

`attach_for_callback` attaches for the duration of the closure and returns the
thread to where it was, the way `PyGILState_Ensure` and `PyGILState_Release`
bracket `_servername_callback`. It tests for "not ATTACHED" rather than for
DETACHED, so a thread a stop-the-world has already moved to SUSPENDED routes
through `attach_thread` and parks there until the world starts again.

`a_callback_inside_a_detached_call_waits_for_the_world` stops the world with a
thread detached, then turns that thread loose at a callback and asserts it does
not run until the world starts. With the transition disabled it fails.

Assisted-by: Claude

* openssl: attach around the callbacks that run Python

`_servername_callback` and `_msg_callback` reach the interpreter from inside an
SSL call -- they take a reference to the Python callback, build arguments and
call it. That call is about to detach, and running Python from a detached
thread runs it on a thread a stop-the-world requester counts as parked.
`_servername_callback` opens with `PyGILState_Ensure()` for the same reason.

Both now rejoin the interpreter for the duration of the callback and give the
thread back afterwards. The reference to the callback moves inside that
section, since taking it is itself an interpreter operation; the check for
whether a callback is set at all stays outside, so a socket with none set never
reaches the interpreter.

No behavior change yet: nothing detaches around these calls, so
`attach_for_callback` finds the thread already attached and just runs.

Assisted-by: Claude

* openssl: detach around the SSL calls that wait

On a socket with a timeout the wait lands in `select` -> `sock_wait`, which
already detaches. On a blocking socket there is no such return: `SSL_read`
blocks in `recv(2)` through `impl Read for &PySocket`, with the thread attached
and the connection's write lock held, so the world could not be stopped for as
long as the peer stayed silent. `SSL_do_handshake`, `SSL_read_ex`,
`SSL_write_ex` and `SSL_shutdown` all run between `Py_BEGIN_ALLOW_THREADS` and
`Py_END_ALLOW_THREADS`; these now do too, in both socket and BIO mode as there.

The connection lock stays held across the call and so becomes a detaching lock:
a thread reaching the same socket gives up its interpreter rather than wait for
it attached. `connection` is `#[pytraverse(skip)]`, so a collection does not
walk into it and never takes that lock -- which is the rule for opting in,
though the skip is what supplies it here rather than the missing `Traverse`.

A server that completes a handshake and then says nothing used to deadlock the
whole process: the collector suspended the main thread at a safepoint and then
waited forever for the reader, so even the test's own timeout could not fire.
It now collects in 3 ms. Verified separately that a Python `_msg_callback`
still runs from inside the handshake -- 920 invocations across 40 handshakes
with a collector looping, five runs clean.

test_ssl on this backend fails the same 8 tests before and after, by name, and
openssl.rs draws no clippy warning it did not draw before.

Assisted-by: Claude

* lock: assert the opt-in rule against every stop-the-world section

Not implementing `Traverse` for `PyDetachingRwLock` states the rule to a
collection: a payload holding one cannot derive `Traverse`, so a collection
cannot walk into it. It says nothing to the other sections that stop the world
-- fork, traceback dumps, frame enumeration -- and `#[pytraverse(skip)]` steps
around it besides, which is how `_SSLSocket.connection` holds one. For those
the rule was a comment.

`set_world_stopped` records, on the one thread still running inside a stopped
world, that it is that thread; `lock_shared` and `lock_exclusive` assert it is
not set. A section that took one of these could block on a lock a parked thread
holds and only that section can release, which is the deadlock the rule exists
to prevent. Debug builds only; release builds track nothing.

Nothing in the tree trips it: 180 rounds of collect, `sys._current_frames`,
`faulthandler.dump_traceback` and 18 forks with four threads churning
bytearrays, plus test_gc/test_bytes/test_threading/test_memoryview/test_buffer
on a debug build, all clean.

`taking_one_while_stopping_the_world_is_caught` takes one with the flag set and
asserts the panic, so the guard is not dead code.

Assisted-by: Claude

* clippy: drop std_instead_of_core suppressions

1.98 no longer reports `std::io` items for the lint, so the six `expect`
attributes for it are unfulfilled. Also drops `from_iter_instead_of_collect`
from the workspace lint table, which 1.98 removed.

Assisted-by: Claude

* lock: spell out why the detaching rwlock exists

States the motivation as the three-thread cycle it avoids: how a stop reaches
a DETACHED thread but not an ATTACHED one, why a thread blocked on a lock
reaches no safepoint, and why the waiter rather than the holder gives way.

Puts it on `RawDetachingRwLock`, which is public and so rendered; the module
doc is private and keeps only the hook description.

Assisted-by: Claude

* fcntl: raise the error the call returned

The six detached calls discarded the `io::Error` and read `errno` again after
`allow_threads`, which re-attaches in between and can park on the way. `lockf`
already converts the returned error; these now do too.

Assisted-by: Claude

* openssl: allocate the read buffer through the vm

Without a `buffer` argument `read_len` is whatever non-negative size the caller
passed, so `vec![0u8; read_len]` aborts on allocation failure.
`new_zeroed_bytes` raises `MemoryError` instead, as the two other reads in this
file already do.

Assisted-by: Claude

* lock: leave no attached blocking acquire on a detaching lock

`lock_upgradable` starts from holding nothing, so it detaches like
`lock_shared`. A recursive read cannot: it may be the re-entrant take of a lock
this thread holds, so detaching there parks a thread holding it, and staying
attached stalls stop-the-world. `RawRwLockRecursive` is no longer implemented,
which removes `read_recursive` from these locks; nothing took one.

The assertion test no longer replaces the panic hook, which is process-wide and
was suppressing panic output from whatever else ran beside it.

Assisted-by: Claude

* vm: wait for the actual block in the stop-the-world test

The worker signalled before `read()` and the test slept 50ms, so a stop could
complete with nothing blocked on the lock and the test would pass having
checked nothing. It now publishes its thread id from inside the interpreter and
the test waits for that slot to reach DETACHED, bounded so an acquire that
never detaches fails rather than hangs.

Assisted-by: Claude
2026-08-28 16:20:39 +09:00
Andrej730 e2f7529f32 str.format: reject non-existing !b format conversion (#8597) 2026-08-26 15:42:53 +09:00
Jeong, YunWon b4e282a6b9 compiler: end the missing-comma diagnostic past the whole second atom (#8594)
`missing_comma_expression_error` returned its span as `(index, next + 1)`,
where `next` is the byte index at which the second atom starts.  The `+ 1`
is a fixed one-byte width, so the reported `end_offset` matched CPython
only when that atom was a single ASCII character:

    (a b)    end 5, CPython 5
    (a bb)   end 5, CPython 6
    (a bbb)  end 5, CPython 7
    (a β)    end 4, CPython 5

`adjacent_atom_end` already measures an atom -- identifiers including
non-ASCII ones, string literals and numbers -- and is what the first atom
is measured with three lines above.  Use it for the second one too.

Assisted-by: Claude
2026-08-26 00:50:30 +09:00
Joshua Megnauth 60c08b45be host_env: rustix for unlinkat, fix clippy deny (#8591)
Like the other patches, this greatly simplifies our unlinkat code and is
overall nicer because it uses the syscall directly on Linux.

As an added benefit, this commit adds WASI support and fixes a clippy
deny. The old code caused clippy to complain that the WASI branch
bypassed host_env for remove/unlink.
2026-08-25 09:52:02 +09:00
Luan Taraschi 782d5d2639 Warn instead of aborting when a class namespace holds a non-string key (#8581)
* Warn instead of aborting when a class namespace holds a non-string key

type() took the whole process down when the namespace it was handed had
a key that was not an exact str:

    >>> type("MyClass", (), {1: 2})
    thread 'main' panicked at crates/vm/src/builtins/dict.rs:781:65:
    dict has non-string keys: [PyObject PyInt { value: 1 }]

to_attributes called expect() on downcast_exact, so a str subclass hit
the same line, and that one names an attribute as well as a str does.
PyAttributes is keyed by interned strings and can hold nothing else, so
a str subclass is now interned like any other name, and a key that is no
kind of string is skipped, with the caller deciding what the skip means.
type() warns once per class, the way CPython does, and
_thread.start_new_thread raises the TypeError an ordinary call already
raises for the same mapping.

The key itself still does not land in the class dict, which is what
test_type_lookup_mro_reference needs, so that one stays skipped with the
reason rewritten.

Assisted-by: Claude Code:claude-opus-5

* Mark test_type_lookup_mro_reference as an expected failure

It aborted the runner before, which is why it was skipped. Now that it
only fails, the run can carry it: five runs in a row report it as an
expected failure, and it cannot turn into a pass while the class dict
drops the key its lookup needs.

Assisted-by: Claude Code:claude-opus-5
2026-08-24 17:52:18 +09:00
Joshua Megnauth 9b6feb5132 unicodedata: Fix Bidirectional, improve parser (#8548)
We can save space by calculating the diffs between modern Unicode and
3.2.0 and storing membership information where valid. This avoids
storing entire tables for 3.2.0, and is also more correct in the long
run since it handles absence from 3.2.0 correctly. I switched over Bidi
to this new method which partially fixed the test. Unfortunately, our
Unicode data is more up to date than Python 3.14 so the test fails for
modern Unicode. I updated the test to 3.15 as per review, and now our
bidi passes the test.
2026-08-24 17:51:53 +09:00
Jeong, YunWon f87cfe7e7a Match CPython on code objects, ast, symtable and syntax error positions (#8580)
* Guard all/any/tuple(genexpr) calls when the generator is a coroutine

`maybe_optimize_function_call()` reserves a `skip_optimization` label for
every `name(genexpr)` call and, for `all`, `any` and `tuple`, emits an
identity guard against the builtin plus an inlined loop. The port skipped
both whenever the generator expression's symbol table was a coroutine, so
`all(await x for x in xs)` and `all(x async for x in xs)` compiled to a
plain call.

An `await` or an `async for` in the generator does not disqualify the
shape: the inlined `FOR_ITER` raises the same `TypeError` that calling the
builtin on an async generator raises, which is what
test_builtin test_builtin_call_async_genexpr_no_crash asserts.

This was the last code-level difference against CPython across `Lib/`:
comparing every file's code tree by structure, opcode and constant value
(qualnames aside, which moved in 3.14.3+, and set constants compared by
value rather than by hash order) now matches on 1720 of 1720 comparable
files, up from 1719.

Assisted-by: Claude Code:claude-opus-5

* Name the ellipsis type `ellipsis`

`type(...).__name__`, its `__qualname__`, and `types.EllipsisType.__name__`
read `EllipsisType`.

Assisted-by: Claude Code:claude-opus-5

* Align compiler front end and instruction positions with CPython

Reject a bare generator expression in a class header and a format spec
nested more than two deep. Both parse here; the reference grammar has no
rule for either, since a class header only takes `arguments` and the
tokenizer runs out of nesting levels at the third format spec.

Scan the interpolations a format spec carries inside another format spec,
so `f"{x:{y:{z}}}"` reaches `z` when building the symbol table.

Give every generic function's type params scope a `.defaults` slot,
whether or not the signature has any default, so `co_varnames` and
`co_nlocals` match. Classes and type aliases keep theirs empty.

Decide an unparenthesized sole generator argument by the parser's
`parenthesized` flag instead of scanning the source for the shape of its
element. `_sum((d := x - c) * d for x in data)` opens with a parenthesized
group the rest of the expression continues, which the scan read as the
generator's own parentheses and left the call's out of its range.

Drop empty f-string fragments unconditionally. A concatenation whose
fragments are all empty now loads its empty string at the whole
concatenation instead of at whichever fragments happened to be plain
string literals.

Keep a byte order mark in source handed over as text, and report it as an
invalid non-printable character. Reading a file to freeze strips it, as
the encoded-bytes path already did.

Carry the filename into the errors `compile(..., PyCF_ONLY_AST)` raises;
they reported `<unknown>` or an empty name.

Across `Lib/`, the 1729 files that compile on both sides now agree on
opcodes, constants, flags, variable names, names, and exception tables,
and on instruction positions in all but 7 files, where a compound
statement whose body ends in a trailing `;` ends one column short.

Assisted-by: Claude Code:claude-opus-5

* Align ast module output with CPython

- Keep lone surrogates in string, f-string and t-string literal values by
  reading such a literal from its source; the literal-value helpers move
  out of `Compiler` into `rustpython_codegen` and `ConstantLiteral::Str`
  holds `Wtf8Buf`.
- Give `{expr=}` interpolations their leading text as a Constant and
  default their conversion to `repr`, in both f-strings and t-strings.
- Span folded consecutive literals from the first of them to the last.
- Take the `:` into a format spec's range only when the parser left it
  out, instead of always widening by one.
- Report a node end that lands on a line start as that line, column 0.
- Give a generator expression written straight into a call's parentheses
  the range of those parentheses, in the preprocess pass, replacing
  codegen's source scan and `_ast`'s one-column adjustment.
- Drop the expectedFailure on test_ast_line_numbers_with_parentheses.

Assisted-by: Claude Code:claude-opus-5

* Align symbol table output with CPython

- Register an import as `DEF_IMPORT` alone, and an annotated parameter as
  a plain parameter, so `import x; global x` is accepted and annotated
  parameters are not reported as annotated names.
- Record a `global` declaration in the module block as well, and resolve a
  name a `global` in an enclosing scope covers as an implicit global, so a
  class body reading such a name emits `LOAD_NAME`.
- Resolve a name bound nowhere as an implicit global instead of leaving
  its scope unknown.
- Require a binding only for a name an explicit `nonlocal` declared;
  a free variable that reached the scope any other way already resolved.
- Name a generator expression's block `genexpr`; the code object keeps
  `<genexpr>`.
- Locate a `def`/`class` block at its keyword rather than at the first
  decorator. `decorated_definition_range()` moves from `Compiler` to
  `rustpython_codegen` for that.
- Carry a comprehension symbol's flags over when inlining it into a parent
  entry that only holds a free variable propagated from a child.
- Leave `__conditional_annotations__` out of an annotation block's
  symbols and have the compiler cook up the free variable, which places
  it after the ones the symbol table supplies.
- Check `from __future__` placement while building the symbol table, and
  give `symtable.symtable()` the same docstring stripping and future
  feature validation the compiler does.
- Floor `co_stacksize` at 1.

Assisted-by: Claude Code:claude-opus-5

* Locate the eval return and the interactive print like CPython

Leave `eval` mode's `RETURN_VALUE` without a location, so the exit block
is duplicated per reaching path and each copy carries the location of the
branch that jumps to it. `a and b` now ends with two returns as it does
in CPython, and `a if b else c` gives the first one the `a` it returns.

Emit an interactive `CALL_INTRINSIC_1(Print)` at the expression statement
rather than wherever the expression left the location, which differ for
`(a := 10)` and `f'{0:fz}'`.

Assisted-by: Claude Code:claude-opus-5

* Give interactive mode the conditional annotations cell

`compile_program_single()` emitted the `__conditional_annotations__` set
and its name accesses but never added the cell that holds it, so a module
compiled in `single` mode was missing the `MAKE_CELL` and the cellvar that
the same source gets in `exec` mode.

Assisted-by: Claude Code:claude-opus-5

* Give compiler-raised SyntaxErrors an end position

`CodegenError` and `SymbolTableError` now carry an `end_location`
alongside `location`, and `CompileError::python_end_location()` returns
it, so errors such as "'await' outside function" set `end_lineno` and
`end_offset` instead of leaving them None.

`SymbolTableBuilder::error_ranged()` builds both positions from a range,
replacing the inline `source_location()` calls at the error sites.

Drop the `expectedFailure` on
`test_exceptions.SyntaxErrorTests.test_file_source`, which now passes.

Assisted-by: Claude Code:claude-opus-5

* Report parser diagnostics with CPython's wording

`InvalidAnnotatedAssignmentTarget` becomes "illegal target for
annotation", `UnexpectedExpressionToken` becomes plain "invalid syntax"
rather than prefixing the parser's text, and the list-recovery
diagnostics ("Expected an expression or a '}'" and its siblings) join the
two that already mapped to "invalid syntax".

Assisted-by: Claude Code:claude-opus-5

* Punctuate the code object repr like CPython

`repr(code)` was missing the comma after the address and escaped the
filename through Rust's Debug formatting.

Drop the `expectedFailure` on the six `test_dis` tests that compare
disassembly text, which now pass.

Assisted-by: Claude Code:claude-opus-5

* Match CPython's parser error positions

A syntax error the parser reports counts its columns in characters, so
`source_location()` converts with UTF-32 rather than UTF-8; an offset
inside a character walks back to where that character starts.

Spans the parser reported differently:

- an error between two tokens covered nothing, and now covers one
  character, since the narrowest token still covers one
- a "was never closed" bracket ends at column 0
- an unterminated string literal ends where it starts
- "leading zeros in decimal integer literals" spans the run of zeros
- an exponent with no digits and no sign is blamed on the digit before
  the exponent letter, which the tokenizer puts back

Assisted-by: Claude Code:claude-opus-5

* codegen: seek to the finally body's own scopes before copying it

An early exit from a try block emits an extra copy of the finally body.
Nested scopes are handed out by position, and the cursors still sit inside
the try block's own run of scopes there, so the copy took those instead of
the ones the finally body opens: a generator expression got a sibling's
symbol table and raised "the symbol 'k' must be present in the symbol
table", or, where the sibling was a named scope, built a code object with
no `.0` argument that raised UnboundLocalError when it ran.

Seek the cursors to the first scope beginning on or after the finally
body's first line before compiling the copy. The existing restore then
leaves the try statement's own copies starting from the same place.

Assisted-by: Claude
2026-08-23 14:32:56 +09:00
Luan Taraschi 97a142d809 Bound the recursion in exception group split and subgroup (#8584)
Both walk nested groups by calling themselves back through
vm.call_method, and neither pushes a Python frame, so the frame limit
never sees the nesting and the native stack runs out first. A group
nested past the recursion limit segfaults:

    e = TypeError(1)
    for _ in range(exceeds_recursion_limit()):
        e = ExceptionGroup("eg", [e])
    e.split(TypeError)      # dumps core

vm.with_recursion is the guard for exactly this, the same one comparison
and repr already use, and it turns the crash into the RecursionError
CPython raises. test_deep_split and test_deep_subgroup were skipped on
the segfault and now pass.

Assisted-by: Claude Code:claude-opus-5
2026-08-22 23:54:46 +00:00
Luan Taraschi d1e80365d6 Drop the handler-table borrow before running a signal handler (#8582)
trigger_signals borrowed the handler table for the whole dispatch loop
and the borrow was still alive while the Python handler ran. A handler
that disarms itself, which is the ordinary way to write one, reached for
the same cell:

    >>> import signal
    >>> def h(signum, frame): signal.signal(signal.SIGUSR1, signal.SIG_IGN)
    ...
    >>> signal.signal(signal.SIGUSR1, h)
    >>> signal.raise_signal(signal.SIGUSR1)
    thread 'main' panicked at crates/vm/src/stdlib/_signal.rs:255:43:
    RefCell already borrowed

The handler now comes out of the table one signal at a time, and the
borrow ends before it runs. Reading inside the loop rather than once up
front also keeps the table current, so a handler that arms or disarms
another signal is obeyed for the rest of the pass.

Assisted-by: Claude Code:claude-opus-5
2026-08-23 08:33:14 +09:00
github-actions[bot]andgithub-actions[bot] ffd10d9094 Update doc DB for CPython 3.14.7 (#8579)
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
2026-08-23 00:12:30 +09:00
이광효 dd32207408 Use non-raising lookup for default optional attribute access (#8576)
* vm: use non-raising lookup for default attribute access

get_attribute_opt() backs hasattr() and getattr() with a default. It used
get_attr_inner() for every object, then converted AttributeError from a
missing attribute into None. The usual user-object miss therefore built and
dropped an exception just to answer an optional lookup.

Route objects using PyBaseObject::getattro through generic_getattr_opt(),
which returns the missing case without constructing AttributeError. Objects
with a custom getattro slot keep the raising path: their __getattribute__ and
__getattr__ hooks can run Python code, so their exceptions must preserve the
existing behavior. AttributeError from either route, including a descriptor,
is still converted to None; non-AttributeError exceptions propagate.

The new snippet covers ordinary hits and misses, custom __getattribute__ /
__getattr__, descriptor exceptions, and dynamic getattro-slot updates.

Refs youknowone#48

Assisted-by: Codex:GPT-5.6-terra

* vm: use non-raising lookup for optional attributes
2026-08-22 20:55:24 +09:00
Shahar Naveh 50b60dc85c Remove #[repr(C)] from LinkedList (#8575)
* fix doc

* drop `repr(C)]`

* remove needless generics from LinkedList

* clippy
2026-08-22 20:54:18 +09:00
Jeong, YunWonandJean-Marc Le Roux 4ea9e84a3a Give the strong count the bits an unused weak field held (#8574)
* Give the strong count the bits an unused weak field held

RefCount packs its state into one usize and splits the non-flag bits evenly
between a strong and a weak count, so a 32-bit target left the strong count
15 bits. An object reaching 32 767 references then called refcount_overflow,
which aborts the process; on wasm that surfaces as an unreachable trap with
no Python-level error. Two ordinary module imports pass that total.

The weak half is never read and never written. WEAK_COUNT appears once
outside its own definition, in RefCount::new, and nothing in the repository
observes those bits: weak references live in the object's WeakRefList, which
Py::weak_count walks. The strong count now takes every bit the three flags
leave, which is 29 on a 32-bit target and 61 on a 64-bit one.

The tests run on wasm32-wasip2, where the old layout traps and the new one
passes. A 64-bit host passes either way, since 31 bits already covered them.

Fixes #8469

Assisted-by: Claude Code:claude-opus-5

* Return the strong count as usize so a 64-bit target cannot truncate it

The count is 61 bits wide on a 64-bit target once it takes the bits the weak
field held, so a u32 return truncates above 4 294 967 295 references: inc
would read a wrapped 0 and re-increment, and dec would read a wrapped 1 and
free a live object. A 32-bit target is unaffected, where 29 bits fit u32.

Assisted-by: Claude Code:claude-opus-5

* Cover the refcount ceiling through inc and dec

inc_by writes its own overflow check, so a test built on it leaves inc and
dec unexercised. The reported aborts came through inc, one reference at a
time.

Assisted-by: Claude Code:claude-opus-5

---------

Co-authored-by: Jean-Marc Le Roux <jeanmarc@lx.industries>
2026-08-22 16:42:12 +09:00
Shahar Naveh c645e17f9a Use ruff_python_ast::name::Name for symtable and compiler (#8344)
* Use `ruff_python_ast::name::Name` for symtable and compiler

* apply suggestion

* fix tests
2026-08-22 13:24:07 +09:00
Luan Taraschi e17555459f Reject the string format flags CPython refuses (#8571)
A sign, a space or an alternate form parsed fine on a string spec and
then had no effect:

    >>> format('ab', '+')
    'ab'
    >>> f"{'ab':#5}"
    'ab   '

CPython raises ValueError for all three. format_string already refused z
and an explicit '=' alignment with the same family of messages, so the
three checks go next to those, in the order CPython reports them: sign,
then z, then the alternate form, then the alignment.

Assisted-by: Claude Code:claude-opus-5
2026-08-22 12:43:38 +09:00
Luan Taraschi b9f591b665 Follow CPython's padding rules in a2b_base64 (#8570)
With strict_mode=True the decoder accepted padding CPython rejects:

    >>> binascii.a2b_base64(b'YWJj=', strict_mode=True)
    b'abc'

It also dropped data in the default mode, because it returned at the
first pad that completed a quad:

    >>> binascii.a2b_base64(b'abc=a')
    b'i\xb7'          # CPython: b'i\xb7\x1a'

The loop now counts pads and decides at the end, the way CPython does,
so a stray pad is ignored outside strict mode and named as leading,
excess or discontinuous inside it. DecodeError::InvalidPadding was dead
in this file and now carries the excess padding message.

test_base64_strict_mode and test_base64_excess_data were marked as
expected failures and pass now.

Assisted-by: Claude Code:claude-opus-5
2026-08-22 12:43:05 +09:00
Luan Taraschi 003307131f Drop what a deque with maxlen of zero is handed (#8567)
append and appendleft trimmed before pushing, and the test they used,
maxlen == len, holds for an empty deque whose bound is zero. The pop then
had nothing to remove and the item stayed:

    >>> d = deque(maxlen=0)
    >>> d.append(1)
    >>> list(d)
    [1]

Both now push first and trim after, which is the order CPython uses, so a
bound of zero drops what just arrived. extend, extendleft, insert, rotate,
the operators and the constructor were already right.

Assisted-by: Claude Code:claude-opus-5
2026-08-22 12:42:40 +09:00
Luan Taraschi d86ec309b1 Apply the format spec to a bool instead of dropping it (#8566)
format_bool answered "True" or "False" for every spec that carries no
presentation type, so width, fill, alignment and sign were all discarded:

    >>> f"{True:>5}"
    'True'

CPython has no bool.__format__ of its own. It uses int's, where an empty
spec on a subclass gives str(self) and everything else formats the integer.
The empty spec keeps the spelled out answer, the rest now goes to
format_int, which also brings back the errors an integer spec raises.

Assisted-by: Claude Code:claude-opus-5
2026-08-22 12:42:10 +09:00
Luan Taraschi c3d22bb225 Insert the item rather than its key in bisect.insort (#8565)
insort_left and insort_right rebound `x` to `key(x)` and then handed that
same value to both the search and `a.insert`, so the object the caller
passed in never reached the list:

    >>> words = ["a", "ccc"]
    >>> bisect.insort(words, "bb", key=len)
    >>> words
    ['a', 2, 'ccc']

The key now feeds the search only, and the insert keeps the original.

Assisted-by: Claude Code:claude-opus-5
2026-08-22 12:41:53 +09:00
Luan Taraschi cdb8a8dd83 Fix str.expandtabs aborting on a tab size of zero (#8562)
`"a\tb".expandtabs(0)` panicked with a capacity overflow. CPython returns
`'ab'`: with no width to advance to, the tabs come out and nothing else
moves. `expandtabs(-1)` is the same call, since `ExpandTabsArgs::tabsize`
sends every negative value to 0.

`expandtabs` keeps the tab stop in `tab_size` and the current column in
`col_count`, and on a tab it does `tab_size - col_count`. With a tab size of
zero both start at 0, the first character makes `col_count` 1 while
`tab_size` stays 0, and the subtraction underflows. The run of spaces asked
for next is `usize::MAX`, and the allocation aborts the process. A tab has to
follow something on the line to reach it: `"\ta".expandtabs(0)` subtracts 0
from 0 and comes out right by accident.

`BytesInner::expandtabs` already returns early for this and filters the tabs
out. The string version now does the same.

Assisted-by: Claude Code:claude-opus-5
2026-08-21 20:29:22 +09:00
Luan Taraschi c4549e1985 Drop the last two lint expectations clippy 1.98 no longer fulfils (#8568)
Assisted-by: Claude Code:claude-opus-5
2026-08-21 20:28:42 +09:00
hyoinandout e5c8701d44 csv: validate dialect options (#8402)
* csv: validate dialect options

Resolve each dialect once and validate the merged options before
constructing readers and writers. Handle Unicode character parsing
consistently and enable the corresponding CPython CSV tests.

Assisted-by: Tau:gpt-5.6-luna

* cargo fmt

* Validate csv dialect conflicts with line terminators

- Reject dialect characters that overlap any lineterminator character
- Validate Dialect construction consistently and allow non-ASCII terminators
- Unskip csv invalid character coverage now that validation matches behavior

* Remove stale CSV rejection snippet

Removes a RustPython-only assertion that contradicts the
CPython-compatible dialect validation added by this branch.

Scope: test-only
AI-Assisted-By: Codex

* Revert "Remove stale CSV rejection snippet"

This reverts commit 3a145dbba4.

* Reapply "Remove stale CSV rejection snippet"

This reverts commit 0754731a2e.

* fix(csv): complete dialect merge resolution

Restore dialect validation and remove stale quoting logic.

Assisted-by: Codex: GPT-5
2026-08-21 17:17:56 +09:00
Yubin KimandJeong, YunWon 7bd61d17d8 Rebase range iterator __reduce__ to match CPython (#8424)
* Rebase range iterator __reduce__ to match CPython

range_iterator.__reduce__ (and longrange_iterator) returned the original
range plus the current index as pickle state; CPython returns the range
rebased to the current position with a None state. Rebase start by
index * step (clamped to the length) and emit None. __setstate__ is kept
so pickles carrying an integer state still load.

Assisted-by: Claude Code:claude-opus-4-8

* Add snippet test for range iterator __reduce__

Assert the rebased range and None state added in the previous commit. The
snippet runner executes it under both CPython and RustPython, so it also
cross-checks the representation against CPython.

Assisted-by: Claude Code:claude-opus-4-8

* Update extra_tests/snippets/builtin_range.py

---------

Co-authored-by: Jeong, YunWon <69878+youknowone@users.noreply.github.com>
2026-08-21 17:16:40 +09:00
Luan Taraschi 8d0e232111 Fix re.findall reporting a group that did not match (#8563)
findall returns the matched text rather than a match object, so a group that
took no part in the match is reported as an empty value. With one group it
was reported as `None`:

    >>> re.findall(r"(a)?b", "b ab")
    [None, 'a']          # CPython: ['', 'a']

The branch for two or more groups was already right, since it passes `""` to
`Match.groups` as the default, so the two halves of the same function
disagreed with each other.

That default is built as a `str` whatever the pattern is, so a `bytes`
pattern came back with `str` mixed into it:

    >>> re.findall(rb"(a)|(b)", b"ab")
    [(b'a', ''), ('', b'b')]     # CPython: [(b'a', b''), (b'', b'b')]

The empty value is now built once from `isbytes` and both branches use it.
`Match.groups` still reports `None`, which is what CPython does.

Assisted-by: Claude Code:claude-opus-5
2026-08-21 17:13:29 +09:00
Luan Taraschi 3144a00bda Drop the lint expectations clippy 1.98 no longer fulfils (#8564)
`clippy::std_instead_of_core` stopped firing at the four places that carry
an `#[expect]` for it. All four were added for the same false positive, on
items whose `core` counterpart is still unstable.

`unfulfilled_lint_expectations` is denied through `-D warnings`, so the
three clippy jobs and the WASM check fail on current stable for every pull
request, whatever it touches.

Assisted-by: Claude Code:claude-opus-5
2026-08-21 07:46:44 +00:00
Luan Taraschi a72f77884d Fix str.replace with an empty pattern splitting characters (#8561)
Wtf8::replace looks for the pattern with a byte search. An empty pattern
matches at every byte, so the replacement was inserted between the bytes of
a multi-byte character and the result was no longer WTF-8:

    >>> "á".replace("", "-")
    '-ím'          # CPython: '-á-'

from_bytes_unchecked then took that as valid without looking, so every later
read of the string returned something else. An empty pattern now walks code
points instead. A pattern that is not empty stays on the byte search, which
is safe because a WTF-8 sequence never starts inside another one.

Assisted-by: Claude Code:claude-opus-5
2026-08-21 15:37:08 +09:00
Andrej730 5201bf68e5 str.format: fix not raising for unknown conversions (#8560)
* `str.format`: fix not raising for unknown conversions

* Move test to Python, test error msg too
2026-08-21 15:36:32 +09:00
Jeong, YunWon a7981dccc7 Align compiler futures, annotations, and symtable with CPython (#8550)
* Align compiler futures and annotations with CPython

Handle Barry parsing consistently across AST, type-comment, REPL, and WASM paths. Preserve deferred annotation source and scope metadata, and make _symtable conversion cached and linear-time.

Assisted-by: Codex:gpt-5.4

* Fix f-string debug ranges and update Barry/annotate test expectations

Compute the debug f-string source range from the raw leading and
trailing text instead of the comment-stripped text, so a comment inside
a multi-line replacement field no longer shifts the emitted LOAD_CONST
location.

Restrict the obsolete-operator location shift to `<>` by also requiring
a `>` at the reported offset; without it any `ExpectedExpression` that
followed a `<` (`2 <;`) was reported one column to the left.

Add `CodeFlags::FUTURE_MASK` and use it in builtins, the shell, and the
WASM VM instead of repeating the eight-flag union, and collapse the
duplicated Barry diagnostic sequences into `BarrySource::diagnostic`.

Update the `__annotate__` disassembly snapshot to LOAD_FAST_BORROW and
replace the RustPython-only `barry_as_FLUFL` co_flags assertion in
extra_tests with the CPython-matching one.

Assisted-by: Claude Code:claude-opus-5

* Restore the annotated function in __annotate__ qualnames

Signature annotation scopes are compiled in the scope enclosing the
annotated function, so the function name has to be folded back into the
qualname: `f.__annotate__`, `C.m.__annotate__`,
`outer.<locals>.inner.__annotate__`. test_type_annotations
test_annotate_qualname covers this.

test_pyrepl test_future_barry_as_flufl now passes, so drop its
expectedFailure marker.

Assisted-by: Claude Code:claude-opus-5

* Pass safepoints in the attached-thread interpreter tests

`main_and_subinterpreter_run_sections_overlap` parked its workers on a
condvar while attached, and `busy_main_interpreter_does_not_block_subinterpreter`
looped over protocol calls that never reach a safepoint. An attached
thread that never reaches a safepoint cannot be suspended, so a
concurrent process-wide stop-the-world (from the gc test running in
parallel) never completes and the already-stopped sibling interpreter
stays stopped; the second worker then waits in `wait_while_suspended`
until the 30s deadline.

Both loops now call `vm.check_signals()` each iteration, and the condvar
wait uses `wait_timeout` so the lock is released between safepoints.

Reproduced on Linux (4 CPUs): the two tests with `--test-threads=2`
failed 2/40 before and 0/40 after; the full `rustpython-vm` lib binary
failed 1/30 before and 0/30 after.

Assisted-by: Claude Code:claude-opus-5

* Report the obsolete `<>` operator from one place

`<>` was located twice: `BarrySource` recorded the token ranges it
rewrote to `!=`, and `cpython_parse_diagnostic_override` separately
peeked at the bytes around an `ExpectedExpression` location. Both
produced "invalid syntax" spanning the whole operator.

`prepare_barry_as_flufl_source` now records the operator ranges in the
non-Barry case too -- by plain text search, since nothing is rewritten
there -- so `BarrySource::invalid_legacy_operator` covers both, and the
byte-peeking helper is gone. It also defers to an unclosed bracket
earlier in the source, which the diagnostic chain it used to sit in did
for it.

A `<>` that starts a statement now spans both characters: the parser
stops at the `<` rather than one character in, which the byte peek did
not handle.

Assisted-by: Claude Code:claude-opus-5

* Drop a py object's payload before its class

`PyInner` declares `typ` before `payload`, so `drop_in_place` dropped the
class first and `PyAtomicRef::drop` left it null. A `PyWeak` payload is
still linked into the weakref list of the object it points at until its
own `Drop` unlinks it under the stripe lock, which happens after that.
`WeakRefList::add` walks the same list looking for a proxy to reuse and
reads `node.class()` off every node it passes, so it could dereference
the null class of a node on its way out.

`PyInner::dealloc` now runs the two destructors in the other order at all
three of its exit paths, with a compile-time check that no other field
has one.

Reproduced by the new test in about 0.1s, as the panic CI hit in the
c-api `weakrefobject::tests::new_proxy` run:

  panicked at crates/vm/src/object/ext.rs:312:
  unsafe precondition(s) violated: hint::unreachable_unchecked must
  never be reached

Assisted-by: Claude Code:claude-opus-5
2026-08-20 12:47:36 +09:00
Jeong, YunWon f75f951c91 compiler-core: implement DerefMut and IndexMut for Constants (#8557)
`Constants<C>` exposed `Deref` and `Index<ConstIdx>` but neither mutable
counterpart, so an owner of a `CodeObject` could read a constant but not
replace one in place and had to rebuild the whole boxed slice.

`[T]` already carries both halves of the `VarNum` pair in this file.

Assisted-by: Claude
2026-08-20 12:42:23 +09:00
Jeong, YunWon 4fab5c966e Raise where the fuzzer found aborts and stack overflows, and collect with the count in the object header (#8551)
* Correct what the non-unix frame stack is for

The comment said non-unix threading builds have no stop-the-world.
CollectStopTheWorld is gated on `feature = "threading"` alone, and
sys._current_frames stops the world on both paths; the field is the
fallback a reader uses when there is no `top_iframe` to materialize from.

Assisted-by: Claude

* Seek by the whole file position on Windows

`SetFilePointer` answers with the low half of the new position and signals
failure with INVALID_SET_FILE_POINTER, which is also that half of a
position four gigabytes in; telling them apart takes the error code, which
this did not read, so such a seek was reported as an error. Deciding
seekability from it also called such a file unseekable.

`SetFilePointerEx` returns the whole position and a success flag of its
own, which also removes the transmute of the position into halves.

Assisted-by: Claude

* memoryview: tell a value of the wrong kind from one that does not fit

Assigning an item reported every packing failure as a TypeError, so
m[0] = 300 on a 'B' view said the value was the wrong type rather than out
of range. Packing now says which of the two it was, and whether the value's
own code raised, in which case that error is the answer as it is:

    m[0] = 300                       ValueError: invalid value for format 'B'
    m[0] = "x"                       TypeError: invalid type for format 'B'
    m[0] = <__index__ that raises>   the raised error

`struct` reports both as `struct.error` and is unchanged; the kind travels
beside the exception for the caller that tells them apart.

Also: None was read as a deletion, so m[0] = None answered "cannot delete
memory" instead of packing it; and deleting through the mapping protocol
never reached the read-only check, which comes first.

Assisted-by: Claude

* Raise MemoryError for allocations sized by Python input

os.read, _RawIOBase.read, int.to_bytes, struct.pack, ctypes array
creation and the _ssl RAND functions sized a Vec from a Python-supplied
length with vec![], which calls handle_alloc_error and, under
panic = "abort", ends the process. They now allocate through
vm.new_zeroed_bytes and raise MemoryError.

itertools.product built its pools without checking that
len(iterables) * repeat is representable; it now raises OverflowError
"repeat argument too large" and reserves the pool and index vectors
fallibly. repeat is read as isize, so a negative one raises ValueError
"repeat argument cannot be negative" instead of the conversion's message.

_ssl.RAND_bytes and RAND_pseudo_bytes read n as i32, matching the int
they are declared with.

Assisted-by: Claude

* Collect with the count in the object header

A collection kept the count it was working with in a table keyed by the
object's address, and the objects it had proved reachable in a second one.
Between them they were hashed once per candidate and twice per edge in the
heap, which is where most of a collection over a live heap went.

The count now lives in `PyInner::gc_refs`, with `GcBits::COLLECTING` saying
it is meaningful, and reachability is `gc_refs == GC_REACHABLE` rather than
membership in a set. Step 5 splits the candidates and clears the bit in one
pass. gcbench, five interleaved pairs, median: a live heap of 423k objects
goes from 0.101s to 0.055s and a dead one from 0.402s to 0.383s.

The bits, generation, owner and count take eight bytes between them. A
64-bit header had those eight as the padding its alignment forces, so it is
unchanged at 48 bytes; a 32-bit header grows from 24 to 28.

Assisted-by: Claude

* Take an explicit thread stack size as a floor in debug builds

A debug build already started Python threads on 8 MiB rather than Rust's
2 MiB default, but an explicit threading.stack_size(N) went through
verbatim. test_threading asks for 256 KiB, and starting a thread on that
walked off the end of the stack: the guard page fault landed in the
prologue of ExecutingFrame::run.

Unoptimized, that prologue reserves 80,848 bytes where the optimized one
reserves 656 -- execute_instruction is #[inline(always)] and LLVM only
colors stack slots from opt-level 1, so the frame is the sum of all 200
instruction arms' temporaries rather than the largest. A Python call costs
88,672 bytes of native stack there, and threading's bootstrap is six
frames deep, so 256 KiB holds less than half of what starting a thread
takes.

The floor reaches thread::Builder only; threading.stack_size() still
answers with what was asked for, and release builds are unchanged.

Assisted-by: Claude

* Check the native stack on every frame entry

The C-stack guard ran on one frame entry in eight. That asks the margin to
cover eight frames rather than one, and it does not: an unoptimized frame
entered through native code takes 88,672 bytes against a debug margin of
262,144. A recursion whose steps re-enter that way -- `__add__` calling
itself, a sort key that sorts -- ran off the end of the stack instead of
raising RecursionError. On a debug build `class Add: __add__ = lambda s, o:
s + o; Add() + 1` segfaulted on the main thread; it now raises, as it does
under CPython and in release builds.

enter_iframe checked and then called enter_iframe_unchecked, which checked
again; it now leaves the check to the one call.

Measured on a call-dominated benchmark, five interleaved pairs: instructions
retired go up 0.17%, about four per call, which is the stack pointer read
and the compare.

Assisted-by: Claude

* Take an iterable's length hint when a list is filled from it

`map_py_iter` read `__length_hint__` only to pass it to `PyIterIter`, and
returned an empty vector when the hint was `isize::MAX` or more. Collecting
through `PyResult` dropped the iterator's lower bound, so nothing reserved
the room the hint asked for.

`list()`, `list.extend()` and `list.__iadd__()` now reserve it and report a
hint they cannot honour as `MemoryError`; a hint that leaves no room for the
elements the list already holds is passed over, as `list_extend()` does.
`tuple()` and the other callers keep filling up without reserving.

`length_hint_opt` errors other than the `TypeError` it already turns into
`None` now reach the caller instead of being dropped.

`__iadd__` and `inplace_concat` went through `extract_cloned`, which reads
`__len__` and not `__length_hint__`; both call `PyList::extend` now, the way
`list_inplace_concat()` calls `list_extend()`.

The tuple, list and dict fast paths of `extract_elements_inner` reserve their
known length, which the `collect()` they used dropped.

Assisted-by: Claude

* Drop map.__length_hint__

`map_methods` has no `__length_hint__`, so `operator.length_hint()` on a map
answers 0, not the length of what it draws from.

The method walked into the length hint of every iterator it holds, and a
chain of maps 10000 long overflowed the native stack answering for the
outermost one. It also took the longest of its iterators, where a map stops
at the shortest.

Assisted-by: Claude

* Ask for a length hint where each caller asks for it

`map_py_iter` asked the iterable it was handed, for every caller, and reported
what asking raised. Only some callers ask it: `list_extend()` and
`_PyBytes_FromIterator()` ask the iterable, `PySequence_Tuple()` asks the
iterator, and the bytearray constructor asks nothing. `tuple()`, `min()`,
`max()`, `collections.deque()` and `f(*x)` raised for an iterable whose
`__len__` or `__length_hint__` does, where they answer.

Which object is asked is now the caller's to say. `sorted()` asks the iterable,
being `PySequence_List()`.

`bytes_from_object()` stood in for `PyBytes_FromObject()`, for
`bytearray_extend()` and for the bytearray constructor, which do not agree on
this: the first two ask, the last does not. It is split, and assigning to a
bytearray slice takes the constructor's side with `PyByteArray_FromObject()`.

`list.extend()` counted what it held before the iterable had been asked, where
`list_extend()` reads `Py_SIZE(self)` after. A `__length_hint__` that adds to
the list made the overflow guard read a count too small and raise `MemoryError`
where nothing is wrong; one that empties it made the guard skip a reservation
that cannot be served.

Assisted-by: Claude

* Settle product's pool count before it reads its arguments

`product_new()` checks `repeat` and works out `npools` before it calls
`PySequence_Tuple()` on any argument, and fills the pools `npools` times.

The pools were filled by repeating the arguments `repeat` times instead, which
walks that many steps even with no arguments to repeat: `product(repeat=2**62)`
counted up to it rather than answering `[()]`. The count was also worked out
after the arguments had been read, so a repeat too large to serve ran their
code first.

Assisted-by: Claude

* Let the bool format answer with the error its value raised

`pack_single()` leaves `'?'` to `PyObject_IsTrue()` and returns what that
raised. Packing classified the error instead, so a `ValueError` from a
`__bool__` came back as "memoryview: invalid value for format '?'".

Assisted-by: Claude

* Release a cell's old value after the lock

`PyCell::set` dropped what it replaced while still holding the mutex guarding
the cell contents. A `__del__` running from that drop and reading the same cell
waited on a lock its own caller held, so `del it` on a closure variable whose
value has such a `__del__` deadlocked.

The replaced value is now released once the guard is gone, as `Py_XSETREF`
stores before it decrefs.

Assisted-by: Claude

* Have a set iterator hold the set it iterates

The iterator kept only a reference to the inner hash table, so in
`it = iter(A(*args))` the `A()` temporary was the last owner and died as the
call returned, before `it` was bound. A `__del__` reading `it` there saw an
unbound name and its error was printed and ignored.

The iterator now holds the set object, as `si_set` does, and releases it once
exhausted. That release happens after the lock is dropped, where
`setiter_iternext()` puts its `Py_DECREF(so)` past `Py_END_CRITICAL_SECTION()`,
so a `__del__` that iterates again does not wait on a lock the call holds.

Assisted-by: Claude

* Release an exhausted iterator's container after the lock

`PositionIterInternal::_next` overwrote its `IterStatus::Active` while the
caller still held the mutex around it. Dropping the container there ran any
`__del__` under that lock, and a `__del__` that iterated the same object again
blocked on it.

`exhaust()` now hands the container back instead of dropping it, and
`locked_step()` releases it after the guard. list, list_reverseiterator, tuple,
str, dict and its views and reverse views, bytes, bytearray, memoryview,
array, deque, and the enumerate and sequence iterators all go through it.

Assisted-by: Claude

* Unskip test_free_after_iterating

Assisted-by: Claude

* Stop listing test_set as an environment polluter

`check_free_after_iterating` no longer leaves an ignored exception behind, and
the job that reruns the listed tests ten times fails once one of them stops
polluting.

Assisted-by: Claude

* Drop winsound imports left unused

`TryFromBorrowedObject`, `exceptions`, and `ToWideString` have no reference in
the module, which fails the Windows clippy line under `-Dwarnings`.

Assisted-by: Claude

* Ask nothing where the caller takes no room

`map_py_iter` asked the iterator for a length hint on behalf of every caller
that does not reserve, and reported what asking raised. Those callers ask
nothing at all: `tuple()`, `f(*x)`, `bytearray(x)`, `min()`, `max()` and
`collections.deque()` answer for an iterator whose `__length_hint__` raises,
where they had been raising it.

The answer was also never spent. It reached `PyIterIter` for a `size_hint()`
the push loop does not read, so the lookup and any call it made were work
thrown away: `tuple()` over a generator drops 22% of its instructions, and 17%
over an iterator with a `__length_hint__` written in Python.

Assisted-by: Claude

* Stop asking an iterator how long it is to walk it

`PyIter::iter` and `PyIter::into_iter` asked for a length hint and reported
what asking raised. Nothing spent the answer: it reached `PyIterIter` for a
`size_hint()` that every caller either loops past or drops, since collecting
into a `Result` reports no lower bound.

23 operations answered for an iterator whose `__length_hint__` raises, where
they had been raising it: `set`, `frozenset` and the nine `set` methods that
take an iterable, `dict.fromkeys` and the dict view operators, `array` and
`array.extend`, `all`, `any`, `sum`, `io.writelines`, `math.fsum`,
`math.prod`, and `csv.writerow` and `writerows`.

Over a generator, `set()` drops 16% of its instructions and `all()` 23%.

`str.join` and `bytes.join` do ask, reaching their elements through
`PySequence_Fast()`, which fills a list from the iterator. They take
`iter_sized()`, which is now the only way to ask. `iter_without_hint` is gone,
its callers being what `iter` already does.

Assisted-by: Claude

* Name the matrix jobs rather than let the matrix name them

A generated job name lists every value in the matrix entry, so `cargo check`
carried the booleans its dependencies and `skip_ssl` keys expand to, and the
snippets job carried its test arguments and timeout. Adding or removing a key
renames the check, which drops it from the required list until that list is
edited to match. Emptying `env_polluting_tests` renamed three checks this way.

`Run rust tests` and `clippy` keep the names they had. `cargo check` drops the
booleans from six of its nine, and the snippets job drops its arguments and
timeout from all three.

Assisted-by: Claude

* Keep a sequence iterator active when an element raises

`PositionIterInternal::_next` exhausted the iterator for any non-`Return`
result, so an error from `__getitem__` ended the walk. `iter_iternext()`
lets go of its sequence for `IndexError` and `StopIteration` alone, and
`PyIterReturn::from_getitem_result` has already turned the first of those
into the second, so only `StopIteration` exhausts now.

Both deque iterators keep exhausting on their own mutation guard, which
`deque_iternext()` does by zeroing the counter before it raises; they
share one step function for it, and the message it raises is lowercased
to match the three other sites in the module.

Assisted-by: Claude

* Name the caller in the bytes conversion TypeError

An object with no iteration protocol reached `PyObject_GetIter`'s "not
iterable" message, and `bytearray.extend()` reported bytes. Each entry
point now checks for the protocol first and names itself:

    bytes(object())               cannot convert 'object' object to bytes
    bytearray(object())           cannot convert 'object' object to bytearray
    bytearray().extend(object())  can't extend bytearray with object

Assisted-by: Claude

* Take a strong count too large to hold as reachable

`start_gc_refs` clipped a count at `GC_REACHABLE - 1`, a number the
per-reference subtraction could still walk down to zero and collect a
live object. It now stores `GC_REACHABLE`, and `subtract_gc_ref` leaves
that value alone.

Assisted-by: Claude

* Raise AssertionError where a snippet asserts False

`assert False` is removed under `-O`, which the snippet suite may run.

Assisted-by: Claude

* Keep raising for a collection that moved under its iterator

A deque, set or dict iterator raised once and then read as spent. The
guard is sticky: `deque_iternext()` looks at the deque's state before the
count it keeps, and `dictiter_iternextkey()` and `setiter_iternext()`
write a size no collection can have, so every later call finds the same
thing and raises again. `dequereviter_next()` is the one exception,
looking at its count first, so it runs out after the first raise.

Both deque iterators now carry `dequeiterobject.counter` rather than
reading a length back from the deque, and the dict and set iterators
compare the size they captured against the collection's own every time
they are asked how much is left, which is what makes that answer nothing
from the moment the collection changes rather than only once the
iterator has raised.

The set's message is capitalized to match `setiter_iternext()`.

Measured against 3.14.6, for each of deque, reversed deque, set, dict
and a reversed dict view: the hint after the change, the error, the hint
after the error, and what a later call answers.

Assisted-by: Claude

* Give apt-get update a deadline to fail on

The step waits on `apt-get update`, which has no deadline of its own, so
a source that takes the connection and then stops answering holds the
job until the workflow's own timeout. The retry that disables the
Microsoft and azure-cli sources runs only when the update exits
non-zero, which a held connection never does; three jobs on this branch
sat on this step for 20 minutes to five and a half hours.

Each attempt is now bounded, and the transports are given a timeout, so
a source that stops answering reaches the retry.

Assisted-by: Claude
2026-08-20 07:08:03 +09:00
mumallaeng b310b6bf6d Collapse bare ExpectedExpression to 'invalid syntax'; fix '<>' diagnostic offset (#8540)
* Collapse bare ExpectedExpression to 'invalid syntax'; fix '<>' diagnostic offset

`ParseErrorType::ExpectedExpression` currently surfaces as the raw ruff
parser message (e.g. "Expected an expression") to callers that only
depend on `rustpython-compiler` (no `rustpython-vm`). `rustpython-vm`'s
`vm_new.rs` already collapses this to CPython's generic "invalid
syntax" for its own callers; mirror that same collapse inside
`cpython_parse_diagnostic_override` so non-vm consumers get the same
CPython-compatible message.

A bare `<>` outside Barry-as-BDFL mode (`2 <> 3`) lexes as `Less` then
an unexpected `Greater`, so the resulting `ExpectedExpression` location
points at the `>` -- one character past where CPython's tokenizer
(which treats `<>` as a single obsolete token) reports the error.
Detect the `<` immediately preceding the location and shift the
reported range back over it.

Assisted-by: Claude Code:claude-sonnet-5

* Require an adjacent '>' before treating '<' as the obsolete <> operator

CodeRabbit review on #8540: the previous check only looked at the byte
before the ExpectedExpression location for '<', without confirming an
adjacent '>' really follows it. For inputs like a trailing '<' at EOF
this could misclassify an unrelated ExpectedExpression as the bare '<>'
case and report a bogus range. Require both bytes are present before
constructing the diagnostic.

Also remove the now-stale `@unittest.expectedFailure # TODO: RUSTPYTHON`
markers on test_guido_as_bdfl and test_barry_as_bdfl_relative_import,
which pass with this fix (test_barry_as_bdfl and
test_barry_as_bdfl_look_ma_with_no_compiler_flags still need real
Barry-as-BDFL tokenizer support and stay marked).

Assisted-by: Claude Code:claude-sonnet-5
2026-08-19 20:07:39 +09:00
Joshua Megnauth aaa4e65364 host_env: Reject interior NULs for CreateProcessW (#8555) 2026-08-19 13:13:03 +09:00
Jeong, YunWon a0eec84cb0 winsound: drop the imports the NUL-safe PlaySound left behind (#8554)
WideCString::from_vec rejects interior NULs itself, so the explicit check
through exceptions::nul_char_error and the to_wide_with_nul call it fed
both went away; TryFromBorrowedObject arrived unused. Windows clippy
rejects all three, which is every Windows clippy run since.

Assisted-by: Claude
2026-08-19 13:12:35 +09:00
6ea492207d ffi: No interior NULs (part 1) (#8245)
* ffi: No interior NULs (part 1)

Interior NULs is a security hazard for C-style strings. A NUL byte
truncates a string which can lead the caller and callee to see two
different strings. It can cause path traversal attacks where a path in
Python looks complete but it is interpreted differently through FFI.

RustPython needs to handle this for some of its C-API as well as raw
libc or Windows calls. Both Rust's standard library as well as Rustix
handle interior NULs for us with CStrings, so this mostly affects
a handful of Windows functions or areas where we have raw bytes that
weren't checked by CString.

Finally, this PR is non-exhaustive. I will have to rely heavily on
CodeRabbit to help lint it to ensure that interior NUL checks are only
introduced for FFI and not outside of it. Most of RustPython seems to
handle interior NULs already due to CString as well as WideCString.

**Sources:**
* https://owasp.org/www-community/attacks/Embedding_Null_Code
* python/cpython#11656

* rename null_terminated_bytes

---------

Co-authored-by: Jeong, YunWon <69878+youknowone@users.noreply.github.com>
Co-authored-by: Jeong, YunWon <jeong@youknowone.org>
2026-08-18 15:30:34 +00:00