Starting off with WASI version, WASI SDK version, and whether cooperative multithreading is available. All values are required as WASI SDK is the officially supported compiler according to PEP 11.
The marshal writer decided whether an object can be referenced later
(FLAG_REF) from its reference count, so the output for the same value
depended on what else in the process held a reference to its parts, and
differed between the default and the free-threaded builds' view of the
same objects. This is the remaining cause of gh-129724 and the cause of
gh-156504.
FLAG_REF is now set exactly on the objects which are written more than
once in the dump. The writer still makes one pass: it records the
position of the type byte of each object it remembers and of each
TYPE_REF, and when the dump is complete it sets the flags and renumbers
the references. A reference count of one is only used to skip the
hashtable. Interned strings are no longer flagged unconditionally.
The reader is unchanged and the format version is not bumped: both the
old and the new output are loaded by old and new readers.
PyMarshal_WriteObjectToFile() now builds the data in memory and writes
it with one fwrite(), since the flags are only known at the end.
Nothing is written if the object cannot be marshalled.
Set elements are written in the order of their dumps. They were sorted
as (dump, element) pairs, so elements with the same dump were compared.
That raised TypeError for a set of several complex NaNs, which the
compiler can produce by constant folding, making the module impossible
to marshal.
Sort (dump, index, element) tuples, in which the indexes are all
different. Elements with the same dump stay in the order of the set,
as float NaNs did before.
Marshalling a set element can run Python code (__buffer__, an audit
hook) which changes the set. The number of elements was read before
the loop, so a set which grew was written past the end of the list and
one which shrank left NULL items in the list which was then sorted.
Raise RuntimeError("set changed size during iteration") instead.
Previously the marshal writer recorded an error code and converted it into
an exception at the end, replacing the exception which was already raised
with ValueError("unmarshallable object"). Error messages now name the type
of the unsupported object and the required version.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Functions reading marshalled data from a FILE* now raise OSError for I/O
errors and KeyboardInterrupt for interrupted reading, instead of EOFError.
PyMarshal_WriteObjectToFile() and PyMarshal_WriteLongToFile() now detect
I/O errors and interrupted writing instead of ignoring them.
PyMarshal_WriteObjectToFile() now also sets the error indicator if the
value cannot be marshalled.
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
Also fix a crash when unmarshalling a self-referencing tuple.
Co-authored-by: Michael Bommarito <michael.bommarito@gmail.com>
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
The TYPE_FROZENDICT reader reserved a reference slot but never filled it with
r_ref_insert, unlike TYPE_FROZENSET, so a frozendict referenced more than once
failed to load with ValueError.
Loading a reference-tracked dictionary dereferenced a NULL pointer when
the allocation that registers it for back-references failed under low
memory. It now raises MemoryError, matching the tuple and list paths.
Forbid marshalling recursive code, slice and frozendict objects which
cannot be correctly unmarshalled.
Reject invalid marshal data produced by marshalling recursive frozendict
objects which was previously incorrectly unmarshalled.
Add multiple tests for recursive data structures.
Rename from _Py_INTERNAL_ABI_SLOT to _Py_ABI_SLOT
and define the macro using _PyABIInfo_DEFAULT.
Use the ABI slot in stdlib extension modules to enable running
a check of ABI version compatibility.
_tkinter, _tracemalloc and readline don't use the slots, hence they need
explicit handling.
Co-authored-by: Victor Stinner <vstinner@python.org>
Add TYPE_FROZENDICT to the marshal module.
Add C API functions:
* PyAnyDict_Check()
* PyAnyDict_CheckExact()
* PyFrozenDict_Check()
* PyFrozenDict_CheckExact()
* PyFrozenDict_New()
Add PyFrozenDict_Type C type.
Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>
Co-authored-by: Adam Johnson <me@adamj.eu>
Co-authored-by: Benedikt Johannes <benedikt.johannes.hofer@gmail.com>
Writing out an object may involve a slot lookup, which is not safe to do with
an exception raised. In debug mode an assertion failure will occur if this
happens.
The previous `Py_REFCNT(x) == 1` checks can have data races in the free
threaded build. `_PyObject_IsUniquelyReferenced(x)` is a more conservative
check that is safe in the free threaded build and is identical to
`Py_REFCNT(x) == 1` in the default GIL-enabled build.
* Document that slices can be marshalled
* Deduplicate and organize the list of supported types
in docs
* Organize the type code list in marshal.c, to make
it more obvious that this is a versioned format
* Back-fill some historical info
Co-authored-by: Michael Droettboom <mdboom@gmail.com>
* Make slices marshallable
* Emit slices as constants
* Update Python/marshal.c
Co-authored-by: Peter Bierma <zintensitydev@gmail.com>
* Refactor codegen_slice into two functions so it
always has the same net effect
* Fix for free-threaded builds
* Simplify marshal loading of slices
* Only return SUCCESS/ERROR from codegen_slice
---------
Co-authored-by: Mark Shannon <mark@hotpy.org>
Co-authored-by: Peter Bierma <zintensitydev@gmail.com>
Fix warnings when using -Wimplicit-fallthrough compiler flag.
Annotate explicitly "fall through" switch cases with a new
_Py_FALLTHROUGH macro which uses __attribute__((fallthrough)) if
available. Replace "fall through" comments with _Py_FALLTHROUGH.
Add _Py__has_attribute() macro. No longer define __has_attribute()
macro if it's not defined. Move also _Py__has_builtin() at the top
of pyport.h.
Co-Authored-By: Nikita Sobolev <mail@sobolevn.me>
* Add an InternalDocs file describing how interning should work and how to use it.
* Add internal functions to *explicitly* request what kind of interning is done:
- `_PyUnicode_InternMortal`
- `_PyUnicode_InternImmortal`
- `_PyUnicode_InternStatic`
* Switch uses of `PyUnicode_InternInPlace` to those.
* Disallow using `_Py_SetImmortal` on strings directly.
You should use `_PyUnicode_InternImmortal` instead:
- Strings should be interned before immortalization, otherwise you're possibly
interning a immortalizing copy.
- `_Py_SetImmortal` doesn't handle the `SSTATE_INTERNED_MORTAL` to
`SSTATE_INTERNED_IMMORTAL` update, and those flags can't be changed in
backports, as they are now part of public API and version-specific ABI.
* Add private `_only_immortal` argument for `sys.getunicodeinternedsize`, used in refleak test machinery.
* Make sure the statically allocated string singletons are unique. This means these sets are now disjoint:
- `_Py_ID`
- `_Py_STR` (including the empty string)
- one-character latin-1 singletons
Now, when you intern a singleton, that exact singleton will be interned.
* Add a `_Py_LATIN1_CHR` macro, use it instead of `_Py_ID`/`_Py_STR` for one-character latin-1 singletons everywhere (including Clinic).
* Intern `_Py_STR` singletons at startup.
* For free-threaded builds, intern `_Py_LATIN1_CHR` singletons at startup.
* Beef up the tests. Cover internal details (marked with `@cpython_only`).
* Add lots of assertions
Co-Authored-By: Eric Snow <ericsnowcurrently@gmail.com>
This PR adds the ability to enable the GIL if it was disabled at
interpreter startup, and modifies the multi-phase module initialization
path to enable the GIL when loading a module, unless that module's spec
includes a slot indicating it can run safely without the GIL.
PEP 703 called the constant for the slot `Py_mod_gil_not_used`; I went
with `Py_MOD_GIL_NOT_USED` for consistency with gh-104148.
A warning will be issued up to once per interpreter for the first
GIL-using module that is loaded. If `-v` is given, a shorter message
will be printed to stderr every time a GIL-using module is loaded
(including the first one that issues a warning).
* EOFError no longer overrides other errors such as MemoryError or OSError at
the start of the object.
* Raise more relevant error when the NULL object occurs as a code object
component.
* Minimize an overhead of calling PyErr_Occurred().
Remove old aliases which were kept backwards compatibility with
Python 3.8:
* _PyObject_CallMethodNoArgs()
* _PyObject_CallMethodOneArg()
* _PyObject_CallOneArg()
* _PyObject_FastCallDict()
* _PyObject_Vectorcall()
* _PyObject_VectorcallMethod()
* _PyVectorcall_Function()
Update code which used these aliases to use new names.
Here we are doing no more than adding the value for Py_mod_multiple_interpreters and using it for stdlib modules. We will start checking for it in gh-104206 (once PyInterpreterState.ceval.own_gil is added in gh-104204).
* Eliminate all remaining uses of Py_SIZE and Py_SET_SIZE on PyLongObject, adding asserts.
* Change layout of size/sign bits in longobject to support future addition of immortal ints and tagged medium ints.
* Add functions to hide some internals of long object, and for setting sign and digit count.
* Replace uses of IS_MEDIUM_VALUE macro with _PyLong_IsCompact().
For wasmtime 2.0, the stack depth cost is 6% higher. This causes the default max `marshal` recursion depth to blow the stack.
As the default marshal depth is 2000 and Windows is set to 1000, split the difference and choose 1500 for WASI to be safe.
Brett Cannon