* introduce executable specific linker flags
Add PY_CORE_EXE_LDFLAGS and EXE_LDFLAGS which stores executable specific
LDFLAGS, replacing PY_CORE_LDFLAGS for building
executable targets.
If PY_CORE_EXE_LDFLAGS / EXE_LDFLAGS is not provided, then it defaults
to the value of PY_CORE_LDFLAGS which is the existing behaviour.
If both flags are supplied, and there is a need
to distinguish between executable and shared specific LDFLAGS,
in particular, PY_CORE_LDFLAGS should contain the shared specific LDFLAGS.
* documentation for new linker flags
* update Misc folder documentation
* Update Makefile.pre.in
Co-authored-by: Victor Stinner <vstinner@python.org>
---------
Co-authored-by: Filipe Laíns <filipe.lains@gmail.com>
Co-authored-by: Victor Stinner <vstinner@python.org>
Co-authored-by: Filipe Laíns <lains@riseup.net>
The pymalloc huge page support had two problems. First, on
architectures where the default huge page size exceeds the arena
size (e.g. 32 MiB on PPC, 512 MiB on ARM64 with 64 KB base
pages), mmap with MAP_HUGETLB silently allocates a full huge page
even when the requested size is smaller. The subsequent munmap
with the original arena size then fails with EINVAL, permanently
leaking the entire huge page. Second, huge pages were always
attempted when compiled in, with no way to disable them at
runtime. On Linux, if the huge page pool is exhausted, page
faults including copy-on-write faults after fork deliver SIGBUS
and kill the process.
The arena allocator now queries the system huge page size from
/proc/meminfo and skips MAP_HUGETLB when the arena size is not a
multiple of it. Huge pages also now require explicit opt-in at
runtime via the PYTHON_PYMALLOC_HUGEPAGES environment variable,
which is read through PyConfig and respects -E and -I flags.
The config field pymalloc_hugepages is propagated to the runtime
allocators struct so the low-level arena allocator can check it
without calling getenv directly.
Adds a PrivacyInfo.xcprivacy file when packaging `_hashlib` and `_ssl` modules
for iOS (based on the original OpenSSL sources); and adds handling to the build
script to allow any app to add `xcprivacy` handling for a binary module.
Adds tooling to generate and test an iOS XCframework, in a way that will also facilitate
adding other XCframework targets for other Apple platforms (tvOS, watchOS, visionOS and
even macOS, potentially).
---------
Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>
Modifies the iOS testbed project to add a test plan. This simplifies the iOS
test runner, as we can now use the built-in log streaming to see test results.
It also allows for some other affordances, like providing a default LLDB config,
and using a standardized mechanism for specifying test arguments.
* Doc/c-api/memory.rst: extend --without-pymalloc doc with ASan information
This commit extends the documentation for disabling pymalloc with the `--without-pymalloc` flag regarding why it is worth to use it when enabling AddressSanitizer for Python build (which is done, e.g., in CPython's CI builds).
I have tested the CPython latest main build with both ASan and pymalloc enabled and it seems to work just fine. I did run the `python -m test` suite which didn't uncover any ASan crashes (though, it detected some memory leaks, which I believe are irrelevant here).
I have discussed ASan and this flag with @encukou on the CPython Core sprint on EuroPython 2025. We initially thought that the `--without-pymalloc` flag is needed for ASan builds due to the fact pymalloc must hit the begining of page when determining if the memory to be freed comes from pymalloc or was allocated by the system malloc. In other words, we thought, that ASan would crash CPython during free of big objects (allocated by system malloc). It may be that this was the case in the past, but it is not the case anymore as the `address_in_range` function used by pymalloc is annotated to be skipped from the ASan instrumentation.
This code can be seen here:
https://github.com/python/cpython/blob/acefb978dcb5dd554e3c49a3015ee5c2ad6bfda1/Objects/obmalloc.c#L2096-L2110
While the annotation macro is defined here:
https://github.com/python/cpython/blob/acefb978dcb5dd554e3c49a3015ee5c2ad6bfda1/Include/pyport.h#L582-L598
And the corresponding attribute is documented in:
* for gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-no_005fsanitize_005faddress-function-attribute
* for clang: https://clang.llvm.org/docs/AttributeReference.html#no-sanitize-address-no-address-safety-analysis
* Update Doc/c-api/memory.rst
* Improve --with-address-sanitizer and pymalloc docs
---------
Co-authored-by: Petr Viktorin <encukou@gmail.com>
The iOS testbed now treats the app_packages folder as a site folder. This ensures it is
on the path, but also ensures any .pth files are processed on app startup.
Remove `experimental` qualification for free-threading in the document text. Note that images included in the document will be updated later in the release cycle.
Chris Eibl